Time to rethink haemoglobin threshold guidelines in sickle cell disease.

Alleviating anaemia in patients with sickle cell disease (SCD) is crucial in managing acute complications, mitigating end-organ damage and preventing early mortality. Some disease-modifying and curative therapies have increased haemoglobin (Hb) levels to exceed 100 g/l, a threshold above which complications from red blood cell (RBC) transfusions have occurred, raising concern about whole-blood viscosity-related complications with these therapies. Here we discuss the rationale behind this limit, the effect of viscosity on blood flow and the applicability of this Hb threshold to therapies for SCD beyond RBC transfusions.

Opioids are not a major cause of death of patients with sickle cell disease.

According to the Center of Disease Control and Prevention (CDC) database, the total number of deaths due to opioid overdose from 1999 through 2018 was 840,629. Given the alarming nature of these statistics, patients who requested prescription for opioids became targets of suspicion and possible accusation of maladaptive behavior. Patients with sickle cell disease (SCD) were often not exempt from such accusations and became guilty by association. In order to clarify the effect of opioids on the mortality of patients with SCD, the mortality rates for children and adults with SCD were investigated using the CDC Wide-ranging Online Data for Epidemiologic Research (WONDER) Multiple Cause of Death database which is based on all the death certificates issued in the USA from 1999 to 2018. The data showed that 15,765 patients with SCD died from 1999 to 2018. Only 348 patients with SCD died due to opioids. The CDC database contains 27 categories of death based on ICD-10 codes in patients with SCD, and opioids were the 19th ranking cause of death. Surprisingly the most common causes of death of patients with SCD included circulatory, infection, respiratory, genitourinary, and vaso-occlusive crises/acute chest syndrome disorders in decreasing frequency. The mean age of death of females was 41.9 years and of males 39.3 years (p < 0.0001). Death due to SCD and death due to SCD and opioids were highest in the Southern Region of the USA.

Determinants of the Outcome of the Transition of Children with Sickle Cell Disease to Adult Programs.

Transition of adolescents with sickle cell disease to adult programs is associated with increased morbidity and mortality. The reasons for this poor outcome are not well known. This report describes the various factors that affect the outcome of the transition process. These include four inter-personal factors: country of residence, region within the country of residence, the health care system and intra-personal factors. Each factor is described in some detail. Understanding these factors and the establishment of guidelines or recommendations could improve the outcome of this critical transition in the life of patients with sickle cell disease.

Risk factors associated with increased emergency department utilization in patients with sickle cell disease: a systematic literature review.

Sickle cell disease (SCD), a genetic disorder affecting up to 100,000 patients in the USA, impacts multiple organ systems. The emergency department (ED) is frequently utilized by patients with SCD who have severe pain from vaso-occlusive crises. The goal of this systematic literature review is to identify predictors for ED use among patients with SCD in the USA, as high ED reliance is not ideal because of the potential for discontinuity of care as well as higher costs. PubMed and Embase were searched for articles containing the keywords "sickle cell disease" AND ("emergency" OR "acute care") AND ("utilization" OR "health care") published between 2000 and 26 September 2019. A total of 26 publications were identified meeting the following inclusion criteria: report of ED or acute care clinic use; report of health care utilization for SCD; and report of ED visits independent of hospital admission, ED revisits, inpatient care visits, and SCD care unit visits. Articles unavailable in English or those focused on populations outside the USA were excluded. Of the 26 articles included, 4 were prospective and the remainder were retrospective. Qualitative analysis of the articles revealed a higher rate of ED utilization among adults than children, patients with public insurance than private insurance, and patients with more comorbidities, complications, or pain. Age and pain levels were both commonly cited as predictors of ED utilization. Additional prospective and interventional studies are needed to further define predictors of ED utilization and to uncover treatments that decrease ED visits.

The vaso-occlusive pain crisis in sickle cell disease: Definition, pathophysiology, and management.

Early diagnosis, treatment, and prevention of a vaso-occlusive crisis (VOC) are critical to the management of patients with sickle cell disease. It is essential to differentiate between VOC-associated pain and chronic pain, hyperalgesia, neuropathy, and neuropathic pain. The pathophysiology of VOCs includes polymerization of abnormal sickle hemoglobin, inflammation, and adhesion. Hydroxyurea, L-glutamine, crizanlizumab, and voxelotor have been approved by the US Food and Drug Administration for reducing the frequency of VOCs; the European Medicines Agency has approved only hydroxyurea. Other novel treatments are in late-stage clinical development in both the United States and the European Union. The development of agents for prevention and treatment of VOCs should be driven by our understanding of its pathophysiology.

Transcutaneous electrical nerve stimulation (TENS) for pain management in sickle cell disease.

BACKGROUND: Sickle cell disease (SCD), one of the most common inherited disorders, is associated with vaso-occlusive pain episodes and haemolysis leading to recurrent morbidity, hospital admissions and work or school absenteeism. The crises are conventionally treated with opioids, non-opioids and other adjuvants with the risk of developing complications, addictions and drug-seeking behaviour. Different non-pharmacological treatments, such as transcutaneous electrical nerve stimulation (TENS) have been used for managing pain in other painful conditions. Hence, the efficacy of TENS for managing pain in SCD needs to be reviewed. OBJECTIVES: To assess the benefits and harms of TENS for managing pain in people with SCD who experience pain crises or chronic pain (or both). 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 and the reference lists of relevant articles and reviews. Date of the last search: 26 Febraury 2020. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs, where TENS was evaluated for managing pain in people with SCD. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the eligibility of the trials identified by the literature searches according to the inclusion criteria. Two review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using the GRADE guidelines. MAIN RESULTS: One double-blind cross-over RCT with 22 participants with SCD (aged 12 to 27 years) was eligible for inclusion. Following stratification into four pain crises severity grades, participants were then randomised to receive TENS or placebo (sham TENS). The trial was concluded after 60 treatment episodes (30 treatment episodes of each treatment group). There is a lack of clarity regarding the trial design and the analysis of the cross-over data. If a participant was allocated to TENS treatment for an episode of pain and subsequently returned with a further episode of a similar degree of pain, they would then receive the sham TENS treatment (cross-over design). For those experiencing a pain episode of a different severity, it is not clear whether they were re-randomised or given the alternate treatment. Reporting and analysis was based on the total number pain events and not on the number of participants. It is unclear how many participants were crossed over from the TENS group to the sham TENS group and vice versa. The trial had a high risk of bias regarding random sequence generation and allocation concealment; an unclear risk regarding the blinding of participants and personnel; and a low risk regarding the blinding of the outcome assessors and selective outcome reporting. The trial was small and of very low quality; furthermore, given the issue with trial design we were unable to quantitatively analyse the data. Therefore, we present only a narrative summary and caution is advised in interpreting the results. In relation to our pre-defined primary outcomes, the included trial did not report pain relief at two to four weeks post intervention. The trial authors reported that no difference was found in the changes in pain ratings (recorded at one hour and four hours post intervention) between the TENS and the placebo groups. In relation to our secondary outcomes, the analgesic usage during the trial also did not show any difference between groups. Given the quality of the evidence, we are uncertain whether TENS improves overall satisfaction as compared to sham TENS. The ability to cope with activities of daily living was not evaluated. Regarding adverse events, although one case of itching was reported in the TENS group, the site and nature of itching was not clearly stated; hence it cannot be clearly attributed to TENS. Also, two participants receiving 'sham' TENS reported a worsening of pain with the intervention. AUTHORS' CONCLUSIONS: Since we have only included one small and very low-quality trial, with a high risk of bias across several domains, we are unable to conclude whether TENS is harmful or beneficial for managing pain in people with SCD. There is a need for a well-designed, adequately-powered, RCT to evaluate the role of TENS in managing pain in people with SCD.

Case Series and Review of Hematological and Non-Hematological Malignancies in Aging Patients with Sickle Cell Disease in the Hydroxyurea Era.

Survival of adult patients with sickle cell disease has increased progressively since the 1970s. Aging patients with sickle cell disease are at risk of developing comorbidities that are not due to sickle cell disease itself, including malignancies. Many studies tried to assess the incidence of malignancy in patients with sickle cell disease. However, no studies have been done to evaluate cancer incidences in aging sickle cell patients, especially in the hydroxyurea (HU) era. In this review, we assessed the prevalence of malignancies in aging patients with sickle cell disease at our institution with or without HU therapy. Retrospective analysis of hospital records identified patients who had been diagnosed to carry sickle cell disease and malignancies before 2020 using the International Statistical Classification of Diseases and Related Health Problems (ICD-10) coding. Four hundred and eighty-three sickle cell disease patients were seen in our inpatients/outpatients offices. Among these, 12 sickle cell disease patients had a confirmed diagnosis of malignancy. The patients were classified into three categories based on age groups: four patients who were 60 years and older had multiple myeloma. Solid tumors were found in 5/6 patients, aged 40-60 who had the Hb S (HBB: c.20A>T) (ßS/ßS) genotype with signs of iron overload. Two patients, aged 25 and 35, had hematological malignancies. The number of patients on HU was too small to make any comment on relationship to malignancy or mortality. This study is only one institution's experience, further investigation on a larger scale is needed to look into cancer incidences in this population.

Systematic review and meta-analysis of the effect of iron chelation therapy on overall survival and disease progression in patients with lower-risk myelodysplastic syndromes.

The impact of iron chelation therapy (ICT) on overall survival (OS) and progression to acute myeloid leukemia (AML) in patients with iron overload and International Prognostic Scoring System low- or intermediate-risk myelodysplastic syndromes (MDS) is not well understood. We conducted a systematic review and meta-analysis of published studies of ICT in patients with MDS to better elucidate these relationships. We searched PubMed, EMBASE, Cochrane databases, and the World Health Organization Clinical Trial Registry for studies reporting the impact of ICT on OS in patients with low- or intermediate-risk MDS. Studies were examined for demographics, effect measures, and potential bias risk. Fixed and random-effects models were used to calculate adjusted OS and adjusted hazards ratio (aHR) estimates, respectively, among the different studies. Nine observational studies (four prospective and five retrospective) were identified. For patients with MDS, ICT was associated with an overall lower risk of mortality compared with no ICT (aHR 0.42; 95% confidence interval (CI) 0.28-0.62; P < 0.01); however, there was significant heterogeneity across the studies. In studies reporting progression to AML, ICT was not associated with decreased risk of progression (odds ratio 0.68; 95% CI 0.31-1.43; P < 0.030). This systematic review and meta-analysis of nine nonrandomized trials demonstrated significant reduction in risk of mortality in patients with iron overload and low- or intermediate-risk MDS treated with ICT; however, a causal relationship cannot be established. Randomized, controlled trials are needed to more definitively evaluate the relationship between ICT and survival in patients with iron overload and low- or intermediate-risk MDS.

Treatment of dental complications in sickle cell disease.

BACKGROUND: Sickle cell disease is the most common single gene disorder and the commonest haemoglobinopathy found with high prevalence in many populations across the world. Management of dental complications in people with sickle cell disease requires special consideration for three main reasons. Firstly, dental and oral tissues are affected by the blood disorder resulting in several oro-facial abnormalities. Secondly, living with a haemoglobinopathy and coping with its associated serious consequences may result in individuals neglecting their oral health care. Finally, the treatment of these oral complications must be adapted to the systemic condition and special needs of these individuals, in order not to exacerbate or deteriorate their general health. Guidelines for the treatment of dental complications in this population who require special care are unclear and even unavailable in many aspects. Hence this review was undertaken to provide a basis for clinical care by investigating and analysing the existing evidence in the literature for the treatment of dental complications in people with sickle cell disease. This is an update of a previously published review. OBJECTIVES: To assess methods of treating dental complications in people with sickle cell disease. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Review Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 01 August 2019. Additionally, we searched nine online databases (PubMed, Google Scholar, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Literature in the Health Sciences in Latin America and the Caribbean database, African Index Medicus, Index Medicus for South East Asia Region, Index Medicus for the Eastern Mediterranean Region, Indexing of Indian Medical Journals). We also searched the reference lists of relevant articles and reviews and contacted haematologists, experts in fields of dentistry, organizations, pharmaceutical companies and researchers working in this field. Date of last search: 07 November 2019. SELECTION CRITERIA: We searched for published or unpublished randomised controlled studies of treatments for dental complications in people with sickle cell disease. DATA COLLECTION AND ANALYSIS: Two review authors intended to independently extract data and assess the risk of bias of the included studies using standard Cochrane methodologies; however, no studies were identified for inclusion in the review. MAIN RESULTS: No randomised controlled studies were identified. AUTHORS' CONCLUSIONS: This Cochrane Review did not identify any randomised controlled studies assessing interventions for the treatment of dental complications in people with sickle cell disease. There is an important need for randomised controlled studies in this area, so as to identify the most effective and safe method for treating dental complications in people with sickle cell disease.

Pharmacological interventions for painful sickle cell vaso-occlusive crises in adults.

BACKGROUND: Sickle cell disease (SCD) is a group of inherited disorders of haemoglobin (Hb) structure in a person who has inherited two mutant globin genes (one from each parent), at least one of which is always the sickle mutation. It is estimated that between 5% and 7% of the world's population are carriers of the mutant Hb gene, and SCD is the most commonly inherited blood disorder. SCD is characterized by distorted sickle-shaped red blood cells. Manifestations of the disease are attributed to either haemolysis (premature red cell destruction) or vaso-occlusion (obstruction of blood flow, the most common manifestation). Shortened lifespans are attributable to serious comorbidities associated with the disease, including renal failure, acute cholecystitis, pulmonary hypertension, aplastic crisis, pulmonary embolus, stroke, acute chest syndrome, and sepsis. Vaso-occlusion can lead to an acute, painful crisis (sickle cell crisis, vaso-occlusive crisis (VOC) or vaso-occlusive episode). Pain is most often reported in the joints, extremities, back or chest, but it can occur anywhere and can last for several days or weeks. The bone and muscle pain experienced during a sickle cell crisis is both acute and recurrent. Key pharmacological treatments for VOC include opioid analgesics, non-opioid analgesics, and combinations of drugs. Non-pharmacological approaches, such as relaxation, hypnosis, heat, ice and acupuncture, have been used in conjunction to rehydrating the patient and reduce the sickling process. OBJECTIVES: To assess the analgesic efficacy and adverse events of pharmacological interventions to treat acute painful sickle cell vaso-occlusive crises in adults, in any setting. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online, MEDLINE via Ovid, Embase via Ovid and LILACS, from inception to September 2019. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries. SELECTION CRITERIA: Randomized, controlled, double-blind trials of pharmacological interventions, of any dose and by any route, compared to placebo or any active comparator, for the treatment (not prevention) of painful sickle cell VOC in adults. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed studies for eligibility. We planned to use dichotomous data to calculate risk ratio (RR) and number needed to treat for one additional event, using standard methods. Our primary outcomes were participant-reported pain relief of 50%, or 30%, or greater; Patient Global Impression of Change (PGIC) very much improved, or much or very much improved. Our secondary outcomes included adverse events, serious adverse events, and withdrawals due to adverse events. We assessed GRADE and created three 'Summary of findings' tables. MAIN RESULTS: We included nine studies with data for 638 VOC events and 594 participants aged 17 to 42 years with SCD presenting to a hospital emergency department in a painful VOC. Three studies investigated a non-steroidal anti-inflammatory drug (NSAID) compared to placebo. One study compared an opioid with a placebo, two studies compared an opioid with an active comparator, two studies compared an anticoagulant with a placebo, and one study compared a combination of three drugs with a combination of four drugs. Risk of bias across the nine studies varied. Studies were primarily at an unclear risk of selection, performance, and detection bias. Studies were primarily at a high risk of bias for size with fewer than 50 participants per treatment arm; two studies had 50 to 199 participants per treatment arm (unclear risk). Non-steroidal anti-inflammatory drugs (NSAID) compared with placebo No data were reported regarding participant-reported pain relief of 50% or 30% or greater. The efficacy was uncertain regarding PGIC very much improved, and PGIC much or very much improved (no difference; 1 study, 21 participants; very low-quality evidence). Very low-quality, uncertain results suggested similar rates of adverse events across both the NSAIDs group (16/45 adverse events, 1/56 serious adverse events, and 1/56 withdrawal due to adverse events) and the placebo group (19/45 adverse events, 2/56 serious adverse events, and 1/56 withdrawal due to adverse events). Opioids compared with placebo No data were reported regarding participant-reported pain relief of 50% or 30%, PGIC, or adverse events (any adverse event, serious adverse events, and withdrawals due to adverse events). Opioids compared with active comparator No data were reported regarding participant-reported pain relief of 50% or 30% or greater. The results were uncertain regarding PGIC very much improved (33% of the opioids group versus 19% of the placebo group). No data were reported regarding PGIC much or very much improved. Very low-quality, uncertain results suggested similar rates of adverse events across both the opioids group (9/66 adverse events, and 0/66 serious adverse events) and the placebo group (7/64 adverse events, 0/66 serious adverse events). No data were reported regarding withdrawal due to adverse events. Quality of the evidence We downgraded the quality of the evidence by three levels to very low-quality because there are too few data to have confidence in results (e.g. too few participants per treatment arm). Where no data were reported for an outcome, we had no evidence to support or refute (quality of the evidence is unknown). AUTHORS' CONCLUSIONS: This review identified only nine studies, with insufficient data for all pharmacological interventions for analysis. The available evidence is very uncertain regarding the efficacy or harm from pharmacological interventions used to treat pain related to sickle cell VOC in adults. This area could benefit most from more high quality, certain evidence, as well as the establishment of suitable registries which record interventions and outcomes for this group of people.

Rheological properties of sickle erythrocytes in patients with sickle-cell anemia: The effect of hydroxyurea, fetal hemoglobin, and α-thalassemia.

OBJECTIVE: Determine the effect of fetal hemoglobin (HbF) and α-thalassemia on red blood cell (RBC) deformability of patients with sickle-cell anemia (SCA) with and without hydroxyurea (HU). METHODS: Adult patients were enrolled in the Sickle Cell Program of the Cardeza Foundation (Thomas Jefferson University) and were followed up prospectively during the period in which the Multicenter Study of Hydroxyurea (MSH) in patients with SCA was conducted. Ninety-one patients did not receive HU, 20 patients were enrolled in MSH, and 10 patients were enrolled in an open-label study of HU in SCA. Of the 20 patients enrolled in MSH, 11 took HU and nine took placebo. Control group included 113 normal individuals. Red blood cell deformability index (DI) was measured by ektacytometry. RESULTS: Patients with SCA taking HU (n = 21) had higher DI than those taking placebo (n = 9) or who were not taking this therapy (n = 91). In patients without therapy, those with α-thalassemia (n = 31) had higher DI than those without. We showed a significant positive correlation between the level of HbF and DI. SCA patients without α-thalassemia and HbF <10% (n = 48) had lower DI than patients with α-thalassemia and HbF <10% (n = 23) and patients with (n = 8) or without α-thalassemia but with HbF >10% (n = 12). DI measured in patients without α-thalassemia and HbF >10% was higher than in the three other subgroups. CONCLUSION: Elevated levels of HbF with or without HU and α-thalassemia improve sickle RBC rheology, which, in turn, improve the clinical picture of SCA.

The effect of iron chelation therapy on overall survival in sickle cell disease and ß-thalassemia: A systematic review.

Red blood cell transfusions have become standard of care for the prevention of life-threatening anemia in patients with ß-thalassemia and sickle cell disease (SCD). However, frequent transfusions can lead to accumulation of iron that can result in liver cirrhosis, diabetes mellitus, arthritis, arrhythmias, cardiomyopathy, heart failure, and hypogonadotropic hypogonadism. Iron chelation therapy has been shown to reduce serum ferritin levels and liver iron content, but limitations of trial design have prevented any demonstration of improved survival. The objective of this systematic review was to investigate the impact of iron chelation therapy on overall and event-free survival in patients with ß-thalassemia and SCD. Eighteen articles discussing survival in ß-thalassemia and 3 in SCD were identified. Overall iron chelation therapy resulted in better overall survival, especially if it is instituted early and compliance is maintained. Comparative studies did not show any significant differences between available iron chelation agents, although there is evidence that deferiprone is better tolerated than deferoxamine and that compliance is more readily maintained with the newer oral drugs, deferiprone and deferasirox. Iron chelation therapy, particularly the second-generation oral agents, appears to be associated with improved overall and event-free survival in transfusion-dependent patients with ß-thalassemia and patients with SCD.

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.

Conjugate Haemophilus influenzae type b vaccines for sickle cell disease.

BACKGROUND: People affected with sickle cell disease (SCD) are at high risk of infection from Haemophilus influenzae type b (Hib). Before the implementation of Haemophilus influenzae type b conjugate vaccination in high-income countries, this was responsible for a high mortality rate in children under five years of age. In African countries, where coverage of this vaccination is still extremely low, Hib remains one of the most common causes of bacteraemias in children with SCD. The increased uptake of this conjugate vaccination may substantially improve the survival of children with SCD. This is an update of a previously published Cochrane Review. OBJECTIVES: The primary objective was to determine whether Hib conjugate vaccines reduce mortality and morbidity in children and adults with SCD.The secondary objectives were to assess the following in children and adults with SCD: the immunogenicity of Hib conjugate vaccines; the safety of these vaccines; and any variation in effect according to type of vaccine, mode of administration (separately or in combination with other vaccines), number of doses, and age at first dose. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched trial registries (04 July 2018) and contacted relevant pharmaceutical companies to identify unpublished trials.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinoapthies Trials Register: 18 December 2017. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs comparing Hib conjugate vaccines with placebo or no treatment, or comparing different types of Hib conjugate vaccines in people with SCD. DATA COLLECTION AND ANALYSIS: No trials of Hib conjugate vaccines in people with SCD were found. MAIN RESULTS: There is an absence of evidence from RCTs relating to the subject of this review. AUTHORS' CONCLUSIONS: There has been a dramatic decrease in the incidence of invasive Hib infections observed in the post-vaccination era in people with SCD living in high-income countries. Therefore, despite the absence of evidence from RCTs, it is expected that Hib conjugate vaccines may be useful in children affected with SCD, especially in African countries where there is a high prevalence of the disease. The implementation of childhood immunisation schedules, including universal Hib conjugate vaccination, may substantially improve the survival of children with SCD living in low-income countries. We currently lack data to evaluate the potential effect of Hib vaccination among unvaccinated adults with SCD. Further research should assess the optimal Hib immunisation schedule in children and adults with SCD.

Opioid Utilization by Pregnant Women with Sickle Cell Disease and the Risk of Neonatal Abstinence Syndrome.

BACKGROUND: Pregnant women with sickle cell disease (SCD) are at increased risk of maternal and fetal complications. There are limited data on the outcome of the treatment of VOCs with opioids in relation to neonatal complications during pregnancy. METHODS: This is a retrospective cohort study of women with SCD from January 1999 to December 2008. Women with SCD were identified by ICD-9 codes and matched 2:1 to a control group of women on methadone for opioid dependence. The primary outcome was the rate of neonatal abstinence syndrome (NAS). Secondary outcomes included the mean NAS score prior to treatment and the length of treatment. Statistical analysis was performed using SPSS. RESULTS: Twenty-one women with SCD who delivered a total of 23 neonates were included. The rate of NAS among infants born to women with SCD who were treated with opioids at any time was 22% compared to 54% in the methadone controls (p = .010). The rate of NAS was 27% among infants born to women taking opioids daily compared to 54% in the methadone control group (p = .062). CONCLUSIONS: Neonates born to women with SCD who are treated with daily opioids are at a similar risk for developing NAS as those born to mothers on methadone for opioid dependence. Neonates born to women with SCD treated with episodic opioids are at a significantly lower risk for developing NAS than those born to women on methadone for opioid dependence.

From total blood exchange to erythrocytapheresis and back to treat complications of sickle cell disease.

Erythrocytapheresis is an important procedure in the management of certain complications of sickle cell disease, including acute stroke, stroke prevention, acute chest syndrome, and multiorgan failure. Erythrocytapheresis in sickle cell disease simply entails the removal of the patient's red blood cells containing the abnormal sickle hemoglobin and replacing them with normal red blood cells carrying normal hemoglobin. In these procedures, the patient's plasma is not exchanged but is returned to the patient. Several studies have demonstrated that the plasma of patients with sickle cell disease contains several components that increase blood viscosity and initiate or promote vaso-occlusion. These factors include increased levels of globulins, especially immunoglobulin G, acute-phase reactants, fibrinogen, coagulation factors, inflammatory mediators, and heme in the steady state and increase further during painful crises. This may explain why, in certain complications of sickle cell disease, such as acute chest syndrome, hepatic crisis, and priapism, erythrocytapheresis by itself may not be effective despite repetitive cycles of red blood cell exchange. The use of therapeutic plasma exchange in addition to erythrocytapheresis in these situations seems to be useful in resolving them more efficiently. The role of therapeutic plasma exchange in the management of certain complications of sickle cell disease needs further evaluation. This commentary addresses the role of therapeutic plasma exchange in the management of complications of sickle cell disease.

Red blood cell exchange: 2015 American Society for Apheresis consensus conference on the management of patients with sickle cell disease.

The American Society for Apheresis (ASFA) conducted a one-day consensus conference on red blood cell exchange (RBCx) in sickle cell disease (SCD) during its annual meeting in San Antonio, TX, on May 5, 2015. The authors of this article, a subcommittee of ASFA's Clinical Applications Committee, developed several questions with regard to pathophysiology of SCD and use of RBCx in the management of various complications. These questions were provided to the seven invited speakers who are the experts in the field of SCD. Two experts in the field moderated the proceedings of the conference, which was attended by more than 150 participants. After each presentation, there was a summary of the main points by the moderators and an open discussion with questions from the audience. A video recording of the proceedings, as well as each presentation, was made available to the authors. Each author's summary was reviewed and approved by the respective speaker before submission of this manuscript. The subcommittee also developed several key questions to generate a consensus amongst the speakers on key issues for using RBCx for patients with SCD.

Perinatal Maternal Mortality in Sickle Cell Anemia: Two Case Reports and Review of the Literature.

As outcomes of patients with sickle cell anemia improve and survival into adulthood with good quality of life and expectation of long-term survival becomes more common, challenges have developed, including issues related to reproduction. Pregnancy is frequently complicated in patients with sickle cell anemia with mortality up to 4.0%. Here we report maternal perinatal mortality in two women with sickle cell anemia who died post-partum due to acute chest syndrome (ACS), caused by bone marrow fat embolism and review the literature pertinent to this subject. Patient A was a 28-year-old woman with sickle cell anemia with multiple complications. At 30 weeks' gestation she developed hemolysis associated with poor placental function necessitating delivery by C-section. The fetus was delivered successfully but she died due to multi organ failure after delivery. Autopsy showed pulmonary and amniotic fluid embolization. Patient B was a 37-year-old woman with uncomplicated sickle cell anemia who presented with pre term labor and crisis, then ACS and fetal distress. The infant was delivered successfully but the patient died after cardiovascular collapse. Autopsy results showed fat and bone marrow embolization as the cause of death. Pregnancy continues to be high risk for patients with sickle cell anemia including those with mild disease. Maternal perinatal mortality could be unpredictable due to serious complications of sickle cell disease. More studies to assess maternal perinatal mortality are needed.

High mortality among children with sickle cell anemia and overt stroke who discontinue blood transfusion after transition to an adult program.

BACKGROUND: Chronic blood transfusion is the standard of care in the management of overt stroke due to sickle cell anemia (SS) to prevent recurrence of stroke. The problem arises when children are transitioned to adult care where blood transfusion may be discontinued. The purpose of this study was to report the outcome of 22 patients with SS and overt stroke who were transitioned to our adult program between 1993 and 2009. STUDY DESIGN AND METHODS: Transitioned patients were kept on chronic blood transfusion they had as children. Blood bank data were performed and computerized according to FDA and AABB regulations. Records were kept prospectively. Blood counts and percent hemoglobin (Hb)S were obtained before and after transfusion. HbS was kept below 30% after transfusion. Metabolic profiles were obtained every 6 months or more often if needed. Statistical analysis was by the two-tailed t-test. RESULTS: Patients who were compliant with blood transfusion were rarely hospitalized for painful crises. Alloimmunization and iron overload were the major complications of blood transfusion. Eight patients who refused to be maintained on chronic blood transfusion or who were noncompliant died within 1 to 5 years after transition. Causes of death included stroke in two, sudden in three, and multiorgan failure in three. The overall rate of death after transition was 36% and the major cause was discontinuation of blood transfusion. CONCLUSION: Efforts must be made to maintain adequate chronic simple or exchange blood transfusion for children with SS and stroke after transition to adult care.

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.Last search of the Group's Trials Register: 28 November 2015. 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. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. 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. 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 cell survival (depending on dose), this did not lead to fewer painful crises.We will continue to run searches to identify any potentially relevant trials; however, we do not plan to update other sections of the review until new trials are published.