Bloodless management of significantly elevated transcranial Doppler velocity value in a Jehovah's witness child with sickle cell disease: A tertiary centre experience-A case report.

BACKGROUND: Effective management of complications in sickle cell disease (SCD), such as stroke prevention, often necessitates the use of blood transfusions. However, individuals who adhere to the religious tenets of Jehovah's Witnesses strictly abstain from accepting blood transfusions, thereby presenting a formidable challenge in clinical decision-making. CASE REPORT: This is a case of a 3 year old child Jehovah's Witness who was found to have significantly elevated transcranial Doppler (TCD) velocity values between 193 and 203 cm/s, following routine screening. This was an otherwise clinically stable child, whose mother was diligently ensuring he had adequate medical care. Ideally, a prophylactic exchange blood transfusion program would have been commenced immediately but was not done due to due to the lack of consent from the caregiver. Patient was initially on hydroxyurea at 15 mg/kg and self medicating on omega 3 supplements and astymin syrup. Further elevation of TCD velocity upto 242 cm/s after a repeat testing, necessitated graduated increase of the dosage of hydroxyurea to 35 mg/kg to optimize its therapeutic effect, and discontinuation of omega 3 fatty acids and replacement of astymin with folic acid, vitamin C and B complex. Following these adjustments, the TCD dropped to below 190 cm/s reducing the risk of stroke in the child. CONCLUSION: This case report demonstrates the successful implementation of a bloodless management strategy for stroke prevention in a Jehovah's Witness child with SCD. This study contributes to the existing literature by providing valuable insights and practical guidance for healthcare providers facing similar ethical and medical dilemmas.

Treatment Patterns for Sickle Cell Disease among Those with Cerebrovascular Disease in the USA.

BACKGROUND: New treatments and guidelines in sickle cell disease (SCD) have improved the quality and lifespan of SCD patients. Over 90% of people with SCD will live into adulthood, and the majority will live past 50 years of age. However, data on comorbidities and treatments among SCD patients with and without cerebrovascular disease (CVD) are limited. OBJECTIVES: The objective of this study was to describe the outcomes and preventive treatments used on SCD patients with and without CVD, based on a dataset of over 11,000 SCD patients. METHODS: We identified SCD patients with and without CVD from the MarketScan administrative database using validated International Classification of Diseases, 10th Revision, Clinical Modification codes from January 1, 2016, to December 31, 2017. We summarized treatments received (iron chelation, blood transfusion, transcranial Doppler, and hydroxyurea) and tested for differences by CVD status using the t test for continuous variables and the χ2 for categorical variables. We also tested for differences among SCD, stratifying by age (<18 years vs. ≥18 years). RESULTS: Of the 11,441 SCD patients, 833 (7.3%) had CVD. SCD patients with CVD were more likely to have diabetes mellitus (32.4% among those with CVD vs. 13.8% without CVD), congestive heart failure (18.3 vs. 3.4%), hypertension (58.6 vs. 24.7%), chronic kidney disease (17.9 vs. 4.9%), and coronary artery disease (21.3 vs. 4.0%). SCD patients with CVD were more likely to receive a blood transfusion (15.3 vs. 7.2%) and hydroxyurea (10.5 vs. 5.6%). Fewer than 20 patients with SCD were given iron chelation therapy, and none received transcranial Doppler ultrasound. Hydroxyurea was prescribed among a greater percentage of children (32.9%) than adults (15.9%). CONCLUSIONS: There appears to be an underutilization overall of treatment options among SCD patients with CVD. Further research would confirm these trends and explore ways to increase utilization of standard treatments among SCD patients.

Pediatric Patients With Sickle Cell Disease at a Public Hospital: Nutrition, Compliance and Early Experience With L-Glutamine Therapy.

BACKGROUND/AIM: Hydration and hydroxyurea (HU) can modify sickle cell disease (SCD) severity. Optimal nutrition and L-glutamine (Gln) may provide further amelioration. PATIENTS AND METHODS: Reviews of medical records and nutrition surveys were used to investigate severity of pediatric patients with SCD in relation to nutrition, growth, hematologic parameters, and diseasemodifying agents. RESULTS: Among 25 females and 25 males (9.1±7 years), beta-globin genotypes were: HbSS/Sß°, 60%; HbSC, 32%; HbSß+, 8%. The mean number of annual pain crises (APC) was 0.97±1.1. APCs increased ≥2-fold as HbF dropped to <10% with age. Proper hydration and nutrition correlated with younger ages and fewer APCs. Height and weight Z-scores were ≤-1SD in 20% of 35 surveyed patients (12±7.8 years), who had more APCs (2.5±2.5 vs. 1±1.3, p=0.03). Prealbumin levels were overall low. Twenty-two of 28 patients on HU reported ≥90% adherence - with higher mean corpuscular volume (92±9.6 vs. 74±10 f/l, p<0.01). Seventy percent of Gln prescriptions were filled. Compliance over 23 months was ≥70% in 12 patients, including 2 on chronic transfusion. Of 10 evaluable patients, 6 (8.8±2.2 years) had fewer APCs with Gln (mean 0.2 vs. 0.9, p=0.016), with increasing prealbumin levels (14.1 to 15.8 mg/dl, p=0.1). CONCLUSION: Younger, and well-nourished, well-hydrated patients have a milder clinic course. Disease severity was the worse in undernourished teenagers with suboptimal compliance. L-Glutamine with prealbumin monitoring should be considered for further evaluation in pediatric SCD.

Bringing Sickle Cell Disease Care Closer to Home: Feasibility and Efficacy of a Quality Improvement Initiative at a Community Hospital.

Comprehensive care for patients with sickle cell disease has been shown to improve morbidity. However, few studies have focused on community hospitals where the burden of disease is highest. From 2017 to 2019, a series of quality improvement interventions was implemented in Brampton, Toronto, ON, Canada, directed toward pediatric and adult sickle cell disease populations. This included a new adult clinic and education directed at patients and healthcare providers. There were 206 visits from 88 unique patients at the clinic and hydroxyurea (HU) uptake increased from 41.0 to 60.0% over that time (p < 0.001). The annual admission rate by adult patients before and after intervention was 90.0 and 75.0% respectively (p = 0.010). The length of stay of pediatric patients decreased from 3.5 to 2.9 days (p = 0.039). These interventions resulted in significant improvements in acute care utilization and HU use by sickle cell disease patients locally, but larger studies are required to confirm these findings.

Progression of central nervous system disease from pediatric to young adulthood in sickle cell anemia.

Silent cerebral infarcts and arteriopathy are common and progressive in individuals with sickle cell anemia. However, most data describing brain lesions in sickle cell anemia are cross-sectional or derive from pediatric cohorts with short follow-up. We investigated the progression of silent cerebral infarct and cerebral vessel stenosis on brain MRI and MRA, respectively, by describing the incidence of new or worsening lesions over a period of up to 25 years among young adults with sickle cell anemia and explored risk factors for progression. Forty-four adults with sickle cell anemia (HbSS or HbSß0thalassemia), exposed to chronic transfusions (n = 12) or hydroxyurea (n = 32), median age 19.2 years (range 18.0-31.5), received a screening brain MRI/MRA and their results were compared with a clinical exam performed during childhood and adolescence. We used exact log-rank test to compare MRI and MRA progression among any two groups. The hazard ratio (HR) and 95% confidence interval (CI) were calculated from Cox regression analyses. Progression of MRI and MRA occurred in 12 (27%) and 4 (9%) young adults, respectively, relative to their pediatric exams. MRI progression risk was high among participants with abnormal pediatric exams (HR: 11.6, 95% CI: 2.5-54.7) and conditional or abnormal transcranial Doppler ultrasound velocities (HR: 3.9, 95% CI: 1.0-15.1). Among individuals treated with hydroxyurea, high fetal hemoglobin measured in childhood was associated with lower hazard of MRI progression (HR: 0.86, 95% CI: 0.76-0.98). MRA progression occurred more frequently among those with prior stroke (HR: 8.6, 95% CI: 1.2-64), abnormal pediatric exam (P = 0.00084), and elevated transcranial Doppler ultrasound velocities (P = 0.004). Brain MRI/MRA imaging in pediatrics can identify high-risk patients for CNS disease progression in young adulthood, prompting consideration for early aggressive treatments.

Quail (Coturnix japonica) egg attenuated 2-butoxyethanol-induced enzymatic dysregulation, disseminated thrombosis and hemolytic impairment in female wistar rats.

Influence of quail egg on pathologies has increased research interests and series of investigations are currently being done on its influence against these pathologies. The influence of quail egg against 2-butoxyethanol induced hemolysis and disseminated thrombosis was investigated to determine the enzymatic regulations that ensue in the amelioration of deleterious hemolytic and disseminated thrombosis displayed in female Wistar rats. Quail egg was separated into three (3) components (extracts)-quail egg yolk water soluble (QYWS) and fat soluble (QYFS), and albumen extract (QA) and the inorganic and organic compositions were characterized. Depranocytotic assaults was achieved by 250 mg/kg of 2-Butoxyethanol administered for 4 days, the clinical observation revealed a dark purple-red discoloration on the distal tails of the rats and therapeutic applications followed with 1000 mg/kg BWT of QYWS, QYFS and QA, and 15 mg/kg BWT of hydroxyurea. Morphological evaluation, haematological estimations and biochemical evaluations of the influence on the activities of sphingosine kinase-1, RNase, red cell carbonic anhydrase, lactate dehydrogenase, glutathione peroxidase and caspase-3, vis a vis the concentrations of sphingosine-1 phosphate, selenium and zinc (plasma and urine). In vitro anti-inflammatory influence of quail egg components were investigated against hemolysis and key enzymes of inflammation-cycloxygenase, lipoxygenase and ß-glucuronidase. The in vitro anti-inflammatory effects of QYWS, QYFS and QA were concentration dependent from 200 to 800 µg/ml against hemolysis and the key enzymes of inflammation. The characterization of inorganic and organic bioactive composition of the yolk and albumen revealed the presence of folic acid, cobalamin, pyridine, riboflavin, ascorbic acid as well as vitamins D and E, selenium, zinc, iron and calcium. These had reflected in the attenuation of the induced hemolytic and disseminated thrombosis by regulations of enzymes linked to the infarction, apoptosis and oxidative stress characterized in sickle cell index.

VZHE-039, a novel antisickling agent that prevents erythrocyte sickling under both hypoxic and anoxic conditions.

Sickle cell disease (SCD) results from a hemoglobin (Hb) mutation ßGlu6 → ßVal6 that changes normal Hb (HbA) into sickle Hb (HbS). Under hypoxia, HbS polymerizes into rigid fibers, causing red blood cells (RBCs) to sickle; leading to numerous adverse pathological effects. The RBC sickling is made worse by the low oxygen (O2) affinity of HbS, due to elevated intra-RBC concentrations of the natural Hb effector, 2,3-diphosphoglycerate. This has prompted the development of Hb modifiers, such as aromatic aldehydes, with the intent of increasing Hb affinity for O2 with subsequent prevention of RBC sickling. One such molecule, Voxelotor was recently approved by U.S. FDA to treat SCD. Here we report results of a novel aromatic aldehyde, VZHE-039, that mimics both the O2-dependent and O2-independent antisickling properties of fetal hemoglobin. The latter mechanism of action-as elucidated through crystallographic and biological studies-is likely due to disruption of key intermolecular contacts necessary for stable HbS polymer formation. This dual antisickling mechanism, in addition to VZHE-039 metabolic stability, has translated into significantly enhanced and sustained pharmacologic activities. Finally, VZHE-039 showed no significant inhibition of several CYPs, demonstrated efficient RBC partitioning and high membrane permeability, and is not an efflux transporter (P-gp) substrate.

In vitro assessment of the anti-sickling properties of Buchholzia coriacea and Mucuna pruriens seed extracts.

Sickle cell disease is a group of diseases inherited through the gene and it affects the haemoglobin in the red blood cell. This study investigated the methanol seed extract of Buchholzia coriacea for possible in vitro anti-sickling effects and also determined the effect of Mucuna pruriens seed extract on the solubility and oxygen-binding rate of sickle cell haemoglobin. Sickle cell blood was collected from sickle cell disease patients with subsequent addition of 2% sodium metabisulphite to cause more sickling. Varying concentrations of the seed extracts (50%, 25%, 12.5% and 6.25%) were added to the pre-treated blood for these in vitro assays. The results showed that the extract of Buchholzia coriacea significantly (P < 0.05) inhibited sickling at all concentrations with the highest percentage inhibition of 73.3 ± 5.8, reversed sickled erythrocytes at all concentrations with the highest percentage reversal of 83.3 ± 5.8 and significantly (P < 0.05) inhibited polymerisation at all concentrations used in comparison to the parallel control. The extract of Mucuna pruriens seed significantly (P < 0.05) increased the solubility of sickle haemoglobin at 50%, 25%, 12.5% and 6.25% concentrations, increased Fe2+/Fe3+ ratio from 1.7 (control) to 12.2 (50% concentration) and reduced osmotic fragility (at 12.5% and 6.25% concentrations) when compared with parallel control. The results indicate the feasibility of the seed extracts as promising agents in the management of sickle cell disease.

The association between hydroxyurea adherence and opioid utilization among Texas Medicaid enrollees with sickle cell disease.

BACKGROUND: Individuals with sickle cell disease (SCD) suffer from recurrent catastrophic pain crises that are often managed by opioid analgesics. Being adherent to hydroxyurea has been associated with decreased health care resource use for pain; however, evidence of its association with opioid use is limited. OBJECTIVE: To determine if adherence to hydroxyurea is associated with opioid use among patients with SCD. METHODS: This retrospective study used Texas Medicaid data from September 1, 2011, to August 31, 2016 (study period). The index date was the date of hydroxyurea initiation. Patients who were aged 2-63 years at the index date, had ≥ 1 inpatient or ≥ 2 outpatient SCD diagnoses during the study period, had ≥ 1 hydroxyurea prescription during the identification period (September 1, 2011-August 31, 2015), had no diagnosis of other indications for hydroxyurea during the study period, and were continuously enrolled for at least 12 months after the index date were included. Hydroxyurea adherence was measured using medication possession ratio (MPR). The study outcomes (measured 1-year post-index) were (a) opioid use; (b) number of opioid prescriptions; (c) strong opioid use (morphine, hydromorphone, fentanyl, and methadone); (d) number of strong opioid prescriptions; (e) high-dose opioid use (≥ 50 mg morphine milligram equivalent [MME]); and (f) days supply for opioid prescriptions. Covariates included demographic (age and gender) and clinical (vaso-occlusive crisis [VOC], avascular necrosis, iron overload, acute chest syndrome, and blood transfusion) characteristics. Descriptive, bivariate (chi-square and Wilcoxon-Mann-Whitney tests), multiple logistic regression, and negative binomial regression analyses were performed. RESULTS: 1,146 patients (18.3 [12.3] years) met the inclusion criteria. Of these, 19.6% were adherent to hydroxyurea (defined as MPR ≥ 80%) and mean (SD) MPR was 48.3% (29.7%). In the 1 year following hydroxyurea initiation, 923 (80.5%) patients had ≥ 1 opioid prescription with 7.6 (9.4) opioid prescriptions per patient, while 259 (22.6%) patients had ≥ 1 strong opioid prescription with 1.5 (4.4) strong opioid prescriptions per patient. Average (SD) opioid dose was 41.7 (74.3) mg MME, and 27.1% had high daily MME doses (≥ 50 mg MME). Average (SD) opioid days supply was 83.1 (112.2) days. After adjusting for covariates, compared with being nonadherent, being adherent to hydroxyurea was associated with a 50.5% decreased risk of having strong opioids (OR = 0.495, 95% CI = 0.278-0.879, P = 0.0165). Additionally, SCD-related complications (VOC, avascular necrosis, and iron overload) and older age were significant factors associated with opioid use and higher MME. Post hoc analyses showed that being adherent to hydroxyurea was significantly associated with lower probabilities of experiencing SCD-related complications. CONCLUSIONS: Results showed that patients with SCD are moderately adherent to hydroxyurea. Being adherent to hydroxyurea was found to be associated with a lower risk of receiving a prescription for strong opioids. Findings suggest that close monitoring and interventions to improve adherence may help mitigate strong opioid use among these patients. DISCLOSURES: This research did not receive any specific funding. Barner and Kang report grants from Novartis Pharmaceuticals, unrelated to this work. A part of this study was presented as a poster at the American Pharmacists Association (APhA) 2019 Annual Meeting and Exposition (March 22-25, 2019, Seattle, WA) and received the 2019 APhA-APRS Presentation Award in the APhA-APRS Contributed Research Paper, Graduate Student/Fellow/Postdoctoral Scholar category.

Phytomedicines (medicines derived from plants) for sickle cell disease.

BACKGROUND: Sickle cell disease, a common recessively inherited haemoglobin disorder, affects people from sub-Saharan Africa, the Middle East, Mediterranean basin, Indian subcontinent, Caribbean and South America. It is associated with complications and a reduced life expectancy. Phytomedicines (medicine derived from plants in their original state) encompass many of the plant remedies from traditional healers which the populations most affected would encounter. Laboratory research and limited clinical trials have suggested positive effects of phytomedicines both in vivo and in vitro. However, there has been little systematic appraisal of their benefits. This is an updated version of a previously published Cochrane Review. OBJECTIVES: To assess the benefits and risks of phytomedicines in people with sickle cell disease of all types, of any age, in any setting. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, the International Standard Randomised Controlled Trial Number Register (ISRCTN), the Allied and Complimentary Medicine Database (AMED), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Dates of most recent searches: Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Trials Register: 17 March 2020; ISRCTN: 19 April 2020; AMED: 18 May 2020; ClinicalTrials.gov: 24 April 2020; and the WHO ICTRP: 27 July 2017. SELECTION CRITERIA: Randomised or quasi-randomised trials with participants of all ages with sickle cell disease, in all settings, comparing the administration of phytomedicines, by any mode to placebo or conventional treatment, including blood transfusion and hydroxyurea. DATA COLLECTION AND ANALYSIS: Both authors independently assessed trial quality and extracted data. MAIN RESULTS: Three trials (212 participants) of three phytomedicines: Niprisan® (also known as Nicosan®), Ciklavit® and a powdered extract of Pfaffia paniculata were included. The Phase IIB (pivotal) trial suggests that Niprisan® may be effective in reducing episodes of severe painful sickle cell disease crisis over a six-month period (low-quality evidence). It did not appear to affect the risk of severe complications or the level of anaemia (low-quality evidence). The single trial of Cajanus cajan (Ciklavit®) reported a possible benefit to individuals with painful crises, and a possible adverse effect (non-significant) on the level of anaemia (low-quality evidence). We are uncertain of the effect of Pfaffia paniculata on the laboratory parameters and symptoms of SCD (very low-quality of evidence). No adverse effects were reported with Niprisan® and Pfaffia paniculata (low- to very low-quality evidence). AUTHORS' CONCLUSIONS: While Niprisan® appeared to be safe and effective in reducing severe painful crises over a six-month follow-up period, further trials are required to assess its role in managing people with SCD and the results of its multicentre trials are awaited. Currently, no conclusions can be made regarding the efficacy of Ciklavit® and the powdered root extract of Pfaffia paniculata in managing SCD. Based on the published results for Niprisan® and in view of the limitations in data collection and analysis of the three trials, phytomedicines may have a potential beneficial effect in reducing painful crises in SCD. This needs to be further validated in future trials. More trials with improved study design and data collection are required on the safety and efficacy of phytomedicines used in managing SCD.

Blood transfusion for preventing primary and secondary stroke in people with sickle cell disease.

BACKGROUND: Sickle cell disease is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. Sickle cell disease can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Stroke affects around 10% of children with sickle cell anaemia (HbSS). Chronic blood transfusions may reduce the risk of vaso-occlusion and stroke by diluting the proportion of sickled cells in the circulation. This is an update of a Cochrane Review first published in 2002, and last updated in 2017. OBJECTIVES: To assess risks and benefits of chronic blood transfusion regimens in people with sickle cell disease for primary and secondary stroke prevention (excluding silent cerebral infarcts). SEARCH METHODS: We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 8 October 2019. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 19 September 2019. SELECTION CRITERIA: Randomised controlled trials comparing red blood cell transfusions as prophylaxis for stroke in people with sickle cell disease to alternative or standard treatment. There were no restrictions by outcomes examined, language or publication status. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial eligibility and the risk of bias and extracted data. MAIN RESULTS: We included five trials (660 participants) published between 1998 and 2016. Four of these trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of sickle cell disease. Three trials compared regular red cell transfusions to standard care in primary prevention of stroke: two in children with no previous long-term transfusions; and one in children and adolescents on long-term transfusion. Two trials compared the drug hydroxyurea (hydroxycarbamide) and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children); and one in secondary prevention (children and adolescents). The quality of the evidence was very low to moderate across different outcomes according to GRADE methodology. This was due to the trials being at a high risk of bias due to lack of blinding, indirectness and imprecise outcome estimates. Red cell transfusions versus standard care Children with no previous long-term transfusions Long-term transfusions probably reduce the incidence of clinical stroke in children with a higher risk of stroke (abnormal transcranial doppler velocities or previous history of silent cerebral infarct), risk ratio 0.12 (95% confidence interval 0.03 to 0.49) (two trials, 326 participants), moderate quality evidence. Long-term transfusions may: reduce the incidence of other sickle cell disease-related complications (acute chest syndrome, risk ratio 0.24 (95% confidence interval 0.12 to 0.48)) (two trials, 326 participants); increase quality of life (difference estimate -0.54, 95% confidence interval -0.92 to -0.17) (one trial, 166 participants); but make little or no difference to IQ scores (least square mean: 1.7, standard error 95% confidence interval -1.1 to 4.4) (one trial, 166 participants), low quality evidence. We are very uncertain whether long-term transfusions: reduce the risk of transient ischaemic attacks, Peto odds ratio 0.13 (95% confidence interval 0.01 to 2.11) (two trials, 323 participants); have any effect on all-cause mortality, no deaths reported (two trials, 326 participants); or increase the risk of alloimmunisation, risk ratio 3.16 (95% confidence interval 0.18 to 57.17) (one trial, 121 participants), very low quality evidence. Children and adolescents with previous long-term transfusions (one trial, 79 participants) We are very uncertain whether continuing long-term transfusions reduces the incidence of: stroke, risk ratio 0.22 (95% confidence interval 0.01 to 4.35); or all-cause mortality, Peto odds ratio 8.00 (95% confidence interval 0.16 to 404.12), very low quality evidence. Several review outcomes were only reported in one trial arm (sickle cell disease-related complications, alloimmunisation, transient ischaemic attacks). The trial did not report neurological impairment, or quality of life. Hydroxyurea and phlebotomy versus red cell transfusions and chelation Neither trial reported on neurological impairment, alloimmunisation, or quality of life. Primary prevention, children (one trial, 121 participants) Switching to hydroxyurea and phlebotomy may have little or no effect on liver iron concentrations, mean difference -1.80 mg Fe/g dry-weight liver (95% confidence interval -5.16 to 1.56), low quality evidence. We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: risk of stroke (no strokes); all-cause mortality (no deaths); transient ischaemic attacks, risk ratio 1.02 (95% confidence interval 0.21 to 4.84); or other sickle cell disease-related complications (acute chest syndrome, risk ratio 2.03 (95% confidence interval 0.39 to 10.69)), very low quality evidence. Secondary prevention, children and adolescents (one trial, 133 participants) Switching to hydroxyurea and phlebotomy may: increase the risk of sickle cell disease-related serious adverse events, risk ratio 3.10 (95% confidence interval 1.42 to 6.75); but have little or no effect on median liver iron concentrations (hydroxyurea, 17.3 mg Fe/g dry-weight liver (interquartile range 10.0 to 30.6)); transfusion 17.3 mg Fe/g dry-weight liver (interquartile range 8.8 to 30.7), low quality evidence. We are very uncertain whether switching to hydroxyurea and phlebotomy: increases the risk of stroke, risk ratio 14.78 (95% confidence interval 0.86 to 253.66); or has any effect on all-cause mortality, Peto odds ratio 0.98 (95% confidence interval 0.06 to 15.92); or transient ischaemic attacks, risk ratio 0.66 (95% confidence interval 0.25 to 1.74), very low quality evidence. AUTHORS' CONCLUSIONS: There is no evidence for managing adults, or children who do not have HbSS sickle cell disease. In children who are at higher risk of stroke and have not had previous long-term transfusions, there is moderate quality evidence that long-term red cell transfusions reduce the risk of stroke, and low quality evidence they also reduce the risk of other sickle cell disease-related complications. In primary and secondary prevention of stroke there is low quality evidence that switching to hydroxyurea with phlebotomy has little or no effect on the liver iron concentration. In secondary prevention of stroke there is low-quality evidence that switching to hydroxyurea with phlebotomy increases the risk of sickle cell disease-related events. All other evidence in this review is of very low quality.

Interventions for preventing silent cerebral infarcts in people with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Silent cerebral infarcts are the commonest neurological complication in children and probably adults with SCD. Silent cerebral infarcts also affect academic performance, increase cognitive deficits and may lower intelligence quotient. OBJECTIVES: To assess the effectiveness of interventions to reduce or prevent silent cerebral infarcts in people with SCD. SEARCH METHODS: We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 14 November 2019. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 07 October 2019. SELECTION CRITERIA: Randomised controlled trials comparing interventions to prevent silent cerebral infarcts in people with SCD. There were no restrictions by outcomes examined, language or publication status. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. MAIN RESULTS: We included five trials (660 children or adolescents) published between 1998 and 2016. Four of the five trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of SCD. One trial focused on preventing silent cerebral infarcts or stroke; three trials were for primary stroke prevention and one trial dealt with secondary stroke prevention. Three trials compared the use of regular long-term red blood cell transfusions to standard care. Two of these trials included children with no previous long-term transfusions: one in children with normal transcranial doppler (TCD) velocities; and one in children with abnormal TCD velocities. The third trial included children and adolescents on long-term transfusion. Two trials compared the drug hydroxyurea and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children), and one in secondary prevention (children and adolescents). The quality of the evidence was moderate to very low across different outcomes according to GRADE methodology. This was due to trials being at high risk of bias because they were unblinded; indirectness (available evidence was only for children with HbSS); and imprecise outcome estimates. Long-term red blood cell transfusions versus standard care Children with no previous long-term transfusions and higher risk of stroke (abnormal TCD velocities or previous history of silent cerebral infarcts) Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, risk ratio (RR) 0.11 (95% confidence interval (CI) 0.02 to 0.86) (one trial, 124 participants, low-quality evidence); but make little or no difference to the incidence of silent cerebral infarcts in children with previous silent cerebral infarcts on magnetic resonance imaging and normal or conditional TCDs, RR 0.70 (95% CI 0.23 to 2.13) (one trial, 196 participants, low-quality evidence). No deaths were reported in either trial. Long-term red blood cell transfusions may reduce the incidence of: acute chest syndrome, RR 0.24 (95% CI 0.12 to 0.49) (two trials, 326 participants, low-quality evidence); and painful crisis, RR 0.63 (95% CI 0.42 to 0.95) (two trials, 326 participants, low-quality evidence); and probably reduces the incidence of clinical stroke, RR 0.12 (95% CI 0.03 to 0.49) (two trials, 326 participants, moderate-quality evidence). Long-term red blood cell transfusions may improve quality of life in children with previous silent cerebral infarcts (difference estimate -0.54; 95% confidence interval -0.92 to -0.17; one trial; 166 participants), but may have no effect on cognitive function (least squares means: 1.7, 95% CI -1.1 to 4.4) (one trial, 166 participants, low-quality evidence). Transfusions continued versus transfusions halted: children and adolescents with normalised TCD velocities (79 participants; one trial) Continuing red blood cell transfusions may reduce the incidence of silent cerebral infarcts, RR 0.29 (95% CI 0.09 to 0.97 (low-quality evidence). We are very uncertain whether continuing red blood cell transfusions has any effect on all-cause mortality, Peto odds ratio (OR) 8.00 (95% CI 0.16 to 404.12); or clinical stroke, RR 0.22 (95% CI 0.01 to 4.35) (very low-quality evidence). The trial did not report: comparative numbers for SCD-related adverse events; quality of life; or cognitive function. Hydroxyurea and phlebotomy versus transfusions and chelation Primary prevention, children (121 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts (no infarcts); all-cause mortality (no deaths); risk of stroke (no strokes); or SCD-related complications, RR 1.52 (95% CI 0.58 to 4.02) (very low-quality evidence). Secondary prevention, children and adolescents with a history of stroke (133 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts, Peto OR 7.28 (95% CI 0.14 to 366.91); all-cause mortality, Peto OR 1.02 (95%CI 0.06 to 16.41); or clinical stroke, RR 14.78 (95% CI 0.86 to 253.66) (very low-quality evidence). Switching to hydroxyurea and phlebotomy may increase the risk of SCD-related complications, RR 3.10 (95% CI 1.42 to 6.75) (low-quality evidence). Neither trial reported on quality of life or cognitive function. AUTHORS' CONCLUSIONS: We identified no trials for preventing silent cerebral infarcts in adults, or in children who do not have HbSS SCD. Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, but may have little or no effect on children with normal TCD velocities. In children who are at higher risk of stroke and have not had previous long-term transfusions, long-term red blood cell transfusions probably reduce the risk of stroke, and other SCD-related complications (acute chest syndrome and painful crises). In children and adolescents at high risk of stroke whose TCD velocities have normalised, continuing red blood cell transfusions may reduce the risk of silent cerebral infarcts. No treatment duration threshold has been established for stopping transfusions. Switching to hydroxyurea with phlebotomy may increase the risk of silent cerebral infarcts and SCD-related serious adverse events in secondary stroke prevention. All other evidence in this review is of very low-quality.

Potential of isoquercitrin as antisickling agent: a multi-spectroscopic, thermophoresis and molecular modeling approach.

Sickle cell disease is an inherited disease caused by point mutation in hemoglobin (ß-globin gene). Under oxygen saturation, sickle hemoglobin form polymers, leading to rigid erythrocytes. The transition of the blood vessels is altered and initiated by the adhesion of erythrocytes, neutrophils and endothelial cells. Sickle Hemoglobin (HbS) polymerization is a major cause in red blood cells (RBC), promoting sickling and destruction of RBCs. Isoquercitrin, a medicinal bioactive compound found in various medicinal plants, has multiple health benefits. The present study examines the potential of isoquercitrin as an anti-sickle agent, showing a significant decrease in the rate of polymerization as well as sickling of RBCs. Isoquercitrin-induced graded alteration in absorbance and fluorescence of HbS, confirmed their interaction. A negative value of ΔG° strongly suggests that it is a spontaneous exothermic reaction induced by entropy. Negative ΔH° and positive ΔS° predicted that hydrogen and hydrophobic binding forces interfered with a hydrophobic microenvironment of ß6Val leading to polymerization inhibition of HbS. HbS-Isoquercitrin complex exhibits helical structural changes leading to destabilization of the HbS polymer as confirmed by CD spectroscopy. MST and DSC results indicate greater changes in thermophoretic mobility and thermal stability of sickle hemoglobin in the presence of isoquercitrin, respectively. These findings were also supported by molecular simulation studies using DOCK6 and GROMACS. Hence, we can conclude that isoquercitrin interacts with HbS through hydrogen bonding, which leads to polymerization inhibition. Consequently, isoquercitrin could potentially be used as a medication for the treatment of sickle cell disease.Communicated by Ramaswamy H. Sarma.

Drugs for preventing red blood cell dehydration in people with sickle cell disease.

BACKGROUND: Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. This is an updated version of a previously published review. OBJECTIVES: To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We also searched online trials registries for any ongoing trials (01 July 2018).Last search of the Group's Haemoglobinopathies Trials Register: 08 October 2018. SELECTION CRITERIA: Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies for inclusion, assessed study quality and extracted data. MAIN RESULTS: Of the 51 studies identified, three met the inclusion criteria, including 524 people with sickle cell disease aged between 12 and 65 years of age. One study tested the effectiveness of zinc sulphate as compared to placebo and the remaining two assessed senicapoc versus placebo. No deaths were seen in any of the studies (low-quality evidence). The zinc sulphate study showed a significant reduction in painful crises (in a total of 145 participants) over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15) (moderate-quality evidence). However, analysis was restricted due to limited statistical data. Changes to red blood cell parameters and blood counts were inconsistent (very low-quality evidence). No serious adverse events were noted in the study. The Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo showed that the high dose senicapoc showed significant improvement in change in hemoglobin level, the number and proportion of dense red blood cells, red blood cell count and indices and hematocrit value (very low-quality evidence). The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups (low-quality evidence). A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises. AUTHORS' CONCLUSIONS: While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red blood cell survival (depending on dose), this did not lead to fewer painful crises.Given this is no longer an active area of research, this review will no longer be regularly updated.

Adaptation of a microbead assay for the easy evaluation of traditional anti-sickling medicines: application to DREPANOSTAT and FACA.

CONTEXT: Sickle cell disease is a common inherited blood disorder affecting millions of people worldwide. Due to lack of progress in drug discovery for a suitable treatment, sufferers often turn to traditional medicines that take advantage of the plant extracts activity used by traditional healers. OBJECTIVE: This study optimizes an anti-sickling screening test to identify preparations capable of reverting sickle cells back to the morphology of normal red blood cells. We focused on the miniaturization and practicability of the assay, so that it can be adapted to the laboratory conditions commonly found in less developed countries. MATERIALS AND METHODS: We tested two traditional anti-sickling herbal medicines, FACA® and DREPANOSTAT®, composed of Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Rutaceae) and Calotropis procera (Aiton) Dryand. (Apocynaceae) at screening concentrations of hydroethanol extracts from 0.2 to 1 mg/mL. Potential bioactive molecules present in the extracts were profiled using Ultra High Performance Liquid Chromatography coupled with High Resolution Mass Spectrometry (UHPLC-HRMS/MS) method, identified through HRMS, MS/MS spectra and in silico fragmentation tools. RESULTS: Hydroethanol extracts of FACA® and DREPANOSTAT® showed low anti-sickling activity, inhibiting less than 10% of the sickling process. The UHPLC-HRMS/MS profiles identified 28 compounds (18 in FACA® and 15 in DREPANOSTAT®, including common compounds) among which l-phenylalanine is already described as potential anti-sickling agent. When used as positive control, 7 mg/mL phenylalanine reduced the sickled RBC to 52%. DISCUSSION AND CONCLUSIONS: This assay has been optimized for the easy screening of plant extracts or extracted compounds from bioassay guided fractionation, valuable to laboratories from less developed countries.

Phytomedicines (medicines derived from plants) for sickle cell disease.

BACKGROUND: Sickle cell disease, a common recessively inherited haemoglobin disorder, affects people from sub-Saharan Africa, the Middle East, Mediterranean basin, Indian subcontinent, Caribbean and South America. It is associated with complications and a reduced life expectancy. Phytomedicines (medicine derived from plants in their original state) encompass many of the plant remedies from traditional healers which the populations most affected would encounter. Laboratory research and limited clinical trials have suggested positive effects of phytomedicines both in vivo and in vitro. However, there has been little systematic appraisal of their benefits. This is an update of a Cochrane Review first published in 2004, and updated in 2010, 2013, and 2015. OBJECTIVES: To assess the benefits and risks of phytomedicines in people with sickle cell disease of all types, of any age, in any setting. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, the International Standard Randomised Controlled Trial Number Register (ISRCTN), the Allied and Complimentary Medicine Database (AMED), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP).Dates of most recent searches: Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Trials Register: 10 April 2017; ISRCTN: 26 July 2017; AMED: 24 August 2017; ClinicalTrials.gov: 02 August 2017; and the WHO ICTRP: 27 July 2017. SELECTION CRITERIA: Randomised or quasi-randomised trials with participants of all ages with sickle cell disease, in all settings, comparing the administration of phytomedicines, by any mode to placebo or conventional treatment, including blood transfusion and hydroxyurea. DATA COLLECTION AND ANALYSIS: Both authors independently assessed trial quality and extracted data. MAIN RESULTS: Two trials (182 participants) and two phytomedicines Niprisan® (also known as Nicosan®) and Ciklavit® were included. The Phase IIB (pivotal) trial suggests that Niprisan® was effective in reducing episodes of severe painful sickle cell disease crisis over a six-month period (low-quality evidence). It did not affect the risk of severe complications or the level of anaemia (low-quality evidence). No serious adverse effects were reported. The single trial of Cajanus cajan (Ciklavit®) reported a possible benefit to individuals with painful crises (low-quality evidence), and a possible adverse effect (non-significant) on the level of anaemia (low-quality evidence). AUTHORS' CONCLUSIONS: While Niprisan® appeared to be safe and effective in reducing severe painful crises over a six-month follow-up period, further trials are required to assess its role in the management of people with sickle cell disease and the results of its multicentre trials are awaited. Currently no conclusions can be made regarding the efficacy of Ciklavit®. Based on the published results for Niprisan® and in view of the limitations in data collection and analysis of both trials, phytomedicines may have a potential beneficial effect in reducing painful crises in sickle cell disease. This needs to be further validated in future trials. More trials are required on the safety and efficacy of phytomedicines used in managing sickle cell disease.

Sickle cell disease: a malady beyond a hemoglobin defect in cerebrovascular disease.

INTRODUCTION: Sickle cell disease (SCD) is a devastating monogenic disorder that presents as a multisystem illness and affects approximately 100,000 individuals in the United States alone. SCD management largely focuses on primary prevention, symptomatic treatment and targeting of hemoglobin polymerization and red blood cell sickling. Areas covered: This review will discuss the progress of SCD over the last few decades, highlighting some of the clinical (mainly cerebrovascular) and psychosocial challenges of SCD in the United States. In addition, focus will also be made on the evolving science and management of this inherited disease. Expert commentary: Until recently hydroxyurea (HU) has been the only FDA approved therapy for SCD. However, advancing understanding of SCD pathophysiology has led to multiple clinical trials targeting SCD related thrombo-inflammation, abnormal endothelial biology, increased oxidant stress and sickle cell mutation. Yet, despite advancing understanding, available therapies are limited. SCD also imposes great psychosocial challenges for the individual and the affected community, which has previously been under-recognized. This has created a pressing need for complementary adjuvant therapies with repurposed and novel drugs, in addition to the establishment of comprehensive clinics focusing on both the medical treatment and the psychosocial issues associated with SCD.

Interventions for preventing silent cerebral infarcts in people with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Silent cerebral infarcts are the commonest neurological complication in children and probably adults with SCD. Silent cerebral infarcts also affect academic performance, increase cognitive deficits and may lower intelligence quotient. OBJECTIVES: To assess the effectiveness of interventions to reduce or prevent silent cerebral infarcts in people with SCD. SEARCH METHODS: We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 19 September 2016. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 06 October 2016. SELECTION CRITERIA: Randomised controlled trials comparing interventions to prevent silent cerebral infarcts in people with SCD. There were no restrictions by outcomes examined, language or publication status. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. MAIN RESULTS: We included five trials (660 children or adolescents) published between 1998 and 2016. Four of the five trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of SCD. One trial focused on preventing silent cerebral infarcts or stroke; three trials were for primary stroke prevention and one trial dealt with secondary stroke prevention.Three trials compared the use of regular long-term red blood cell transfusions to standard care. Two of these trials included children with no previous long-term transfusions: one in children with normal transcranial doppler (TCD) velocities; and one in children with abnormal TCD velocities. The third trial included children and adolescents on long-term transfusion.Two trials compared the drug hydroxyurea and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children), and one in secondary prevention (children and adolescents).The quality of the evidence was moderate to very low across different outcomes according to GRADE methodology. This was due to trials being at high risk of bias because they were unblinded; indirectness (available evidence was only for children with HbSS); and imprecise outcome estimates. Long-term red blood cell transfusions versus standard care Children with no previous long-term transfusions and higher risk of stroke (abnormal TCD velocities or previous history of silent cerebral infarcts) Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, risk ratio (RR) 0.11 (95% confidence interval (CI) 0.02 to 0.86) (one trial, 124 participants, low-quality evidence); but make little or no difference to the incidence of silent cerebral infarcts in children with previous silent cerebral infarcts on magnetic resonance imaging and normal or conditional TCDs, RR 0.70 (95% CI 0.23 to 2.13) (one trial, 196 participants, low-quality evidence).No deaths were reported in either trial.Long-term red blood cell transfusions may reduce the incidence of: acute chest syndrome, RR 0.24 (95% CI 0.12 to 0.49) (two trials, 326 participants, low-quality evidence); and painful crisis, RR 0.63 (95% CI 0.42 to 0.95) (two trials, 326 participants, low-quality evidence); and probably reduces the incidence of clinical stroke, RR 0.12 (95% CI 0.03 to 0.49) (two trials, 326 participants, moderate-quality evidence).Long-term red blood cell transfusions may improve quality of life in children with previous silent cerebral infarcts (difference estimate -0.54; 95% confidence interval -0.92 to -0.17; one trial; 166 participants), but may have no effect on cognitive function (least squares means: 1.7, 95% CI -1.1 to 4.4) (one trial, 166 participants, low-quality evidence). Transfusions continued versus transfusions halted: children and adolescents with normalised TCD velocities (79 participants; one trial)Continuing red blood cell transfusions may reduce the incidence of silent cerebral infarcts, RR 0.29 (95% CI 0.09 to 0.97 (low-quality evidence).We are very uncertain whether continuing red blood cell transfusions has any effect on all-cause mortality, Peto odds ratio (OR) 8.00 (95% CI 0.16 to 404.12); or clinical stroke, RR 0.22 (95% CI 0.01 to 4.35) (very low-quality evidence).The trial did not report: comparative numbers for SCD-related adverse events; quality of life; or cognitive function. Hydroxyurea and phlebotomy versus transfusions and chelation Primary prevention, children (121 participants; one trial)We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts (no infarcts); all-cause mortality (no deaths); risk of stroke (no strokes); or SCD-related complications, RR 1.52 (95% CI 0.58 to 4.02) (very low-quality evidence). Secondary prevention, children and adolescents with a history of stroke (133 participants; one trial)We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts, Peto OR 7.28 (95% CI 0.14 to 366.91); all-cause mortality, Peto OR 1.02 (95%CI 0.06 to 16.41); or clinical stroke, RR 14.78 (95% CI 0.86 to 253.66) (very low-quality evidence).Switching to hydroxyurea and phlebotomy may increase the risk of SCD-related complications, RR 3.10 (95% CI 1.42 to 6.75) (low-quality evidence).Neither trial reported on quality of life or cognitive function. AUTHORS' CONCLUSIONS: We identified no trials for preventing silent cerebral infarcts in adults, or in children who do not have HbSS SCD.Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, but may have little or no effect on children with normal TCD velocities. In children who are at higher risk of stroke and have not had previous long-term transfusions, long-term red blood cell transfusions probably reduce the risk of stroke, and other SCD-related complications (acute chest syndrome and painful crises).In children and adolescents at high risk of stroke whose TCD velocities have normalised, continuing red blood cell transfusions may reduce the risk of silent cerebral infarcts. No treatment duration threshold has been established for stopping transfusions.Switching to hydroxyurea with phlebotomy may increase the risk of silent cerebral infarcts and SCD-related serious adverse events in secondary stroke prevention.All other evidence in this review is of very low-quality.

Hydroxyurea (hydroxycarbamide) for sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea (hydroxycarbamide), an oral chemotherapeutic drug, ameliorates some of the clinical problems of SCD, in particular that of pain, by raising fetal haemoglobin. This is an update of a previously published Cochrane Review. OBJECTIVES: To assess the effects of hydroxyurea therapy in people with SCD (all genotypes), of any age, regardless of setting. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries.Date of the most recent search: 16 January 2017. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials, of one month or longer, comparing hydroxyurea with placebo, standard therapy or other interventions for people with SCD. DATA COLLECTION AND ANALYSIS: Authors independently assessed studies for inclusion, carried out data extraction and assessed the risk of bias. MAIN RESULTS: Seventeen studies were identified in the searches; eight randomised controlled trials were included, recruiting 899 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sߺthalassaemia (HbSߺthal) genotypes). Studies lasted from six to 30 months.Four studies (577 adults and children with HbSS or HbSߺthal) compared hydroxyurea to placebo; three recruited individuals with only severe disease and one recruited individuals with all disease severities. There were statistically significant improvements in terms of pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use), measures of fetal haemoglobin and neutrophil counts and fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups. There were no consistent statistically significant differences in terms of quality of life and adverse events (including serious or life-threatening events). Seven deaths occurred during the studies, but the rates by treatment group were not statistically significantly different.Two studies (254 children with HbSS or HbSߺthal also with risk of primary or secondary stroke) compared hydroxyurea and phlebotomy to transfusion and chelation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts, but more occurrences of acute chest syndrome and infections in the hydroxyurea and phlebotomy group. There were no consistent statistically significant differences in terms of pain alteration and adverse events (including serious or life-threatening events). Two deaths occurred during the studies (one in a the hydroxyurea treatment arm and one in the control arm), but the rates by treatment group were not statistically significantly different. In the primary prevention study, no strokes occurred in either treatment group but in the secondary prevention study, seven strokes occurred in the hydroxyurea and phlebotomy group (none in the transfusion and chelation group) and the study was terminated early.The quality of the evidence for the above two comparisons was judged as moderate to low as the studies contributing to these comparisons were mostly large and well designed (and at low risk of bias); however evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events and results are applicable only to individuals with HbSS and HbSߺthal genotypes.Of the remaining two studies, one (22 children with HbSS or HbSߺthal also at risk of stoke) compared hydroxyurea to observation; there were statistically significant improvements in terms of measures of fetal haemoglobin and neutrophil counts but no statistically significant differences in terms of adverse events (including serious or life-threatening events).The final study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea - there was statistically significant improvement in terms of measures of fetal haemoglobin, but no statistically significant differences in terms of adverse events (including serious or life-threatening events). No participants died in either of these studies and other outcomes relevant to the review were not reported.The quality of the evidence for the above two comparisons was judged to be very low due to the limited number of participants, the lack of statistical power (as both studies were terminated early with approximately only 20% of their target sample size recruited) and the lack of applicability to all age groups and genotypes. AUTHORS' CONCLUSIONS: There is evidence to suggest that hydroxyurea is effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anaemia of HbSS or HbSߺthal genotypes and in preventing life-threatening neurological events in those with sickle cell anaemia at risk of primary stroke by maintaining transcranial doppler velocities. However, there is still insufficient evidence on the long-term benefits of hydroxyurea, particularly in preventing chronic complications of SCD, recommending a standard dose or dose escalation to maximum tolerated dose. There is also insufficient evidence about the long-term risks of hydroxyurea, including its effects on fertility and reproduction. Evidence is also limited on the effects of hydroxyurea on individuals with HbSC genotype. Future studies should be designed to address such uncertainties.

Blood transfusion for preventing primary and secondary stroke in people with sickle cell disease.

BACKROUND: Sickle cell disease is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. Sickle cell disease can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Stroke affects around 10% of children with sickle cell anaemia (HbSS). Chronic blood transfusions may reduce the risk of vaso-occlusion and stroke by diluting the proportion of sickled cells in the circulation.This is an update of a Cochrane Review first published in 2002, and last updated in 2013. OBJECTIVES: To assess risks and benefits of chronic blood transfusion regimens in people with sickle cell disease for primary and secondary stroke prevention (excluding silent cerebral infarcts). SEARCH METHODS: We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 04 April 2016.We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 25 April 2016. SELECTION CRITERIA: Randomised controlled trials comparing red blood cell transfusions as prophylaxis for stroke in people with sickle cell disease to alternative or standard treatment. There were no restrictions by outcomes examined, language or publication status. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial eligibility and the risk of bias and extracted data. MAIN RESULTS: We included five trials (660 participants) published between 1998 and 2016. Four of these trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of sickle cell disease.Three trials compared regular red cell transfusions to standard care in primary prevention of stroke: two in children with no previous long-term transfusions; and one in children and adolescents on long-term transfusion.Two trials compared the drug hydroxyurea (hydroxycarbamide) and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children); and one in secondary prevention (children and adolescents).The quality of the evidence was very low to moderate across different outcomes according to GRADE methodology. This was due to the trials being at a high risk of bias due to lack of blinding, indirectness and imprecise outcome estimates. Red cell transfusions versus standard care Children with no previous long-term transfusionsLong-term transfusions probably reduce the incidence of clinical stroke in children with a higher risk of stroke (abnormal transcranial doppler velocities or previous history of silent cerebral infarct), risk ratio 0.12 (95% confidence interval 0.03 to 0.49) (two trials, 326 participants), moderate quality evidence.Long-term transfusions may: reduce the incidence of other sickle cell disease-related complications (acute chest syndrome, risk ratio 0.24 (95% confidence interval 0.12 to 0.48)) (two trials, 326 participants); increase quality of life (difference estimate -0.54, 95% confidence interval -0.92 to -0.17) (one trial, 166 participants); but make little or no difference to IQ scores (least square mean: 1.7, standard error 95% confidence interval -1.1 to 4.4) (one trial, 166 participants), low quality evidence.We are very uncertain whether long-term transfusions: reduce the risk of transient ischaemic attacks, Peto odds ratio 0.13 (95% confidence interval 0.01 to 2.11) (two trials, 323 participants); have any effect on all-cause mortality, no deaths reported (two trials, 326 participants); or increase the risk of alloimmunisation, risk ratio 3.16 (95% confidence interval 0.18 to 57.17) (one trial, 121 participants), very low quality evidence. Children and adolescents with previous long-term transfusions (one trial, 79 participants)We are very uncertain whether continuing long-term transfusions reduces the incidence of: stroke, risk ratio 0.22 (95% confidence interval 0.01 to 4.35); or all-cause mortality, Peto odds ratio 8.00 (95% confidence interval 0.16 to 404.12), very low quality evidence.Several review outcomes were only reported in one trial arm (sickle cell disease-related complications, alloimmunisation, transient ischaemic attacks).The trial did not report neurological impairment, or quality of life. Hydroxyurea and phlebotomy versus red cell transfusions and chelationNeither trial reported on neurological impairment, alloimmunisation, or quality of life. Primary prevention, children (one trial, 121 participants)Switching to hydroxyurea and phlebotomy may have little or no effect on liver iron concentrations, mean difference -1.80 mg Fe/g dry-weight liver (95% confidence interval -5.16 to 1.56), low quality evidence.We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: risk of stroke (no strokes); all-cause mortality (no deaths); transient ischaemic attacks, risk ratio 1.02 (95% confidence interval 0.21 to 4.84); or other sickle cell disease-related complications (acute chest syndrome, risk ratio 2.03 (95% confidence interval 0.39 to 10.69)), very low quality evidence. Secondary prevention, children and adolescents (one trial, 133 participants)Switching to hydroxyurea and phlebotomy may: increase the risk of sickle cell disease-related serious adverse events, risk ratio 3.10 (95% confidence interval 1.42 to 6.75); but have little or no effect on median liver iron concentrations (hydroxyurea, 17.3 mg Fe/g dry-weight liver (interquartile range 10.0 to 30.6)); transfusion 17.3 mg Fe/g dry-weight liver (interquartile range 8.8 to 30.7), low quality evidence.We are very uncertain whether switching to hydroxyurea and phlebotomy: increases the risk of stroke, risk ratio 14.78 (95% confidence interval 0.86 to 253.66); or has any effect on all-cause mortality, Peto odds ratio 0.98 (95% confidence interval 0.06 to 15.92); or transient ischaemic attacks, risk ratio 0.66 (95% confidence interval 0.25 to 1.74), very low quality evidence. AUTHORS' CONCLUSIONS: There is no evidence for managing adults, or children who do not have HbSS sickle cell disease.In children who are at higher risk of stroke and have not had previous long-term transfusions, there is moderate quality evidence that long-term red cell transfusions reduce the risk of stroke, and low quality evidence they also reduce the risk of other sickle cell disease-related complications.In primary and secondary prevention of stroke there is low quality evidence that switching to hydroxyurea with phlebotomy has little or no effect on the liver iron concentration.In secondary prevention of stroke there is low-quality evidence that switching to hydroxyurea with phlebotomy increases the risk of sickle cell disease-related events.All other evidence in this review is of very low quality.