Early splenomegaly and septicaemia in homozygous sickle cell disease: A birth cohort study.

BACKGROUND: Patients with homozygous sickle cell disease (HbSS) and clinical splenomegaly by 6 months of age appeared at greater risk of invasive infections after 5 years of the Jamaican Cohort Study. We determined whether this risk remained significant over a longer study period, using a more rigorous definition of infection and examining the contribution of potential confounders. METHODS: Newborn screening of 100,000 consecutive deliveries during 1973-1981 detected 311 births with HbSS. Age at first clinical splenomegaly was used to categorize 285 of these patients in whom this could be determined: at or before 7 months (early), after 7 months (later), or 'never' palpated despite repeated examinations. Infective episodes were confined to 'first infections confirmed by positive culture'. Using a generalized linear model, the risk of septicaemia was assessed in each group, after adjusting for potential confounders. RESULTS: Of 93 'first infections', 42 occurred in 105 subjects in the 'early' group, 49 in 157 subjects in the 'later' group, and two in 23 subjects in the 'never' group; the observed to expected ratio of 1.42, 0.90 and 0.22 was highly significant (p = .003). Assessed as risk ratios, 'early' splenomegaly had a significantly higher risk ratio (RR) for septicaemia (RR = 7.4, confidence interval [CI]: 1.1-50.7, p < .05) when compared to the 'never' group adjusting for vaccine exposure and foetal haemoglobin concentration. The most common organisms were Streptococcus pneumoniae, Salmonella species, Haemophilus influenzae and Staphylococcus aureus. CONCLUSION: Early clinical splenomegaly in HbSS remains a predictor of septicaemia, defining a group that may require closer monitoring.

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 foetal haemoglobin (HbF). This is an update of a previously published Cochrane Review. OBJECTIVES: The aims of this review are to determine through a review of randomised or quasi-randomised studies whether the use of hydroxyurea in people with SCD alters the pattern of acute events, including pain; prevents, delays or reverses organ dysfunction; alters mortality and quality of life; or is associated with adverse effects. In addition, we hoped to assess whether the response to hydroxyurea in SCD varies with the type of SCD, age of the individual, duration and dose of treatment, and healthcare setting. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries. The date of the most recent search was 17 February 2022. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials (RCTs and quasi-RCTs), of one month or longer, comparing hydroxyurea with placebo or standard therapy in people  with SCD. DATA COLLECTION AND ANALYSIS: Authors independently assessed studies for inclusion, carried out data extraction, assessed the risk of bias and assessed the quality of the evidence using GRADE. MAIN RESULTS: We included nine RCTs recruiting 1104 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sߺthalassaemia (HbSߺthal) genotypes). Studies lasted from six to 30 months. We judged the quality of the evidence for the first two comparisons below as moderate to low as the studies contributing to these comparisons were mostly large and well-designed (and at low risk of bias); however, the evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events, and the results are applicable only to individuals with HbSS and HbSߺthal genotypes. We judged the quality of the evidence for the third and fourth comparisons to be very low due to the limited number of participants, the lack of statistical power (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. Hydroxyurea versus placebo Five studies (784 adults and children with HbSS or HbSߺthal) compared hydroxyurea to placebo; four recruited individuals with only severe disease and one recruited individuals with all disease severities. Hydroxyurea probably improves pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use) and life-threatening illness, but we found no difference in death rates (10 deaths occurred during the studies, but the rates did not differ by treatment group) (all moderate-quality evidence). Hydroxyurea may improve measures of HbF (low-quality evidence) and probably decreases neutrophil counts (moderate-quality evidence). There were no consistent differences in terms of quality of life and adverse events (including serious or life-threatening events) (low-quality evidence). There were fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups.  Hydroxyurea and phlebotomy versus transfusion and chelation Two studies (254 children with HbSS or HbSߺthal also with risk of primary or secondary stroke) contributed to this comparison. There were no consistent differences in terms of pain alteration, death or adverse events (low-quality evidence) or life-threatening illness (moderate-quality evidence). Hydroxyurea with phlebotomy probably increased HbF and decreased neutrophil counts (moderate-quality evidence), but there were more occurrences of acute chest syndrome and infections. Quality of life was not reported. 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.  Hydroxyurea versus observation One study (22 children with HbSS or HbSߺthal also at risk of stoke) compared hydroxyurea to observation. Pain alteration and quality of life were not reported. There were no differences in life-threatening illness, death (no deaths reported in either group) or adverse events (very low-quality evidence). We are uncertain if hydroxyurea improves HbF or decreases neutrophil counts (very low-quality evidence). Treatment regimens with and without hydroxyurea One study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea. Pain alteration, life-threatening illness and quality of life were not reported. There were no differences in death rates (no deaths reported in either group), adverse events or neutrophil levels (very low-quality evidence). We are uncertain if hydroxyurea improves HbF (very low-quality evidence). AUTHORS' CONCLUSIONS: There is evidence to suggest that hydroxyurea may be 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 with regard to preventing chronic complications of SCD, or 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 the HbSC genotype. Future studies should be designed to address such uncertainties.

Prophylactic antibiotics for preventing pneumococcal infection in children with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a group of inherited disorders that result in haemoglobin abnormalities and other complications. Injury to the spleen, among other factors, contribute to persons with SCD being particularly susceptible to infection. Infants and very young children are especially vulnerable. The 'Co-operative Study of Sickle Cell Disease' observed an incidence rate for pneumococcal septicaemia of 10 per 100 person-years in children under the age of three years. Vaccines, including customary pneumococcal vaccines, may be of limited use in this age group. Therefore, prophylactic penicillin regimens may be advisable for this population. This is an update of a Cochrane Review which was first published in 2002, and previously updated, most recently in 2017.  OBJECTIVES: To compare the effects of antibiotic prophylaxis against pneumococcus in children with SCD receiving antibiotic prophylaxis compared to those without in relation to: 1. incidence of Streptococcus pneumoniae infection; 2. mortality (as reported in the included studies); 3. drug-related adverse events (as reported in the included studies) to the individual and the community; 4. the impact of discontinuing at various ages on incidence of infection and mortality. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, which is comprised of references identified from comprehensive electronic database searches and also two clinical trials registries: ClinicalTrials.gov and the WHO International Registry Platform (not in 2020 given access issues relating to Covid-19 pandemic). Additionally, we carried out hand searching of relevant journals and abstract books of conference proceedings. Date of the most recent search: 25 January 2021. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials comparing prophylactic antibiotics to prevent pneumococcal infection in children with SCD with placebo, no treatment or a comparator drug. DATA COLLECTION AND ANALYSIS: The standard methodological procedures expected by Cochrane were used. Both authors independently extracted data and assessed trial quality. The authors used the GRADE criteria to assess the certainty of the evidence. MAIN RESULTS: Six trials were identified by the searches, of which three trials were eligible for inclusion. A total of 880 children, who were between three months to five years of age at randomization were included. The included studies were conducted in centres in the USA and in Kingston, Jamaica. In trials that investigated initiation of penicillin on risk of pneumococcal infection, the odds ratio was 0.37 (95% confidence interval 0.16 to 0.86) (two trials, 457 children) (low-certainty evidence), while for withdrawal the odds ratio was 0.49 (95% confidence interval 0.09 to 2.71) (one trial, 400 children) (low-certainty evidence). Adverse drug effects were rare and minor. Rates of pneumococcal infection were found to be relatively low in children over the age of five years. Overall, the certainty of the evidence for all outcomes was judged to be low. The results from the risk of bias assessment undertaken identified two domains in which the risk of bias was considered to be high, these were incomplete outcome data (attrition bias) (two trials) and allocation concealment (selection bias) (one trial). Domains considered to have a low risk of bias for all three trials were selective reporting (reporting bias) and blinding (performance and detection bias). AUTHORS' CONCLUSIONS: The evidence examined was determined to be of low certainty and suggests that prophylactic penicillin significantly reduces risk of pneumococcal infection in children with homozygous SCD, and is associated with minimal adverse reactions. Further research may help to determine the ideal age to safely withdraw penicillin.

Transcranial Doppler velocity among Jamaican children with sickle cell anaemia: determining the significance of haematological values and nutrition.

This study investigated the association of nutritional and haematological variables with maximum time-averaged mean velocity (TAMV) measured by transcranial Doppler (TCD) velocity and the agreement of classification between two protocols. TCD categories included: normal (<170 cm/s), conditional (170-199 cm/s) and abnormal (≥200 cm/s) based on TAMV in distal internal carotid artery (dICA), middle cerebral artery (MCA), internal carotid bifurcation, anterior and posterior cerebral arteries. Of 358 children with sickle cell anaemia (SCA) examined, the mean age (±standard deviation) was 7·4 ± 2·7 years; 13·1% and 6·7% had conditional and abnormal velocities, respectively. Children with abnormal TCD velocities had higher prevalence of prior stroke (P = 0·006). Increased TAMV was associated with younger age (P = 0·001), lower weight (P = 0·001), height (P = 0·007) and oxygen saturation (P = 0·005). There was no association of TAMV with height-age or body mass index (BMI) z-scores. Adjusting for gender, BMI z-score, age, previous stroke and oxygen saturation, mean corpuscular volume (P = 0·005) and reticulocyte count (P = 0·013) were positively associated with TAMV, while haemoglobin concentration (P = 0·009) was negatively associated. There was good agreement [99%; weighted Kappa 0·98 (95% confidence interval 0·89-1), P = 0·0001] in TCD classification using data from five vessels versus two vessels (dICA and MCA). Haematological variables, rather than nutritional status, may be useful markers that identify high-risk children with SCA.

Prophylactic antibiotics for preventing pneumococcal infection in children with sickle cell disease.

BACKGROUND: Persons with sickle cell disease (SCD) are particularly susceptible to infection. Infants and very young children are especially vulnerable. The 'Co-operative Study of Sickle Cell Disease' observed an incidence rate for pneumococcal septicaemia of 10 per 100 person years in children under the age of three years. Vaccines, including customary pneumococcal vaccines, may be of limited use in this age group. Therefore, prophylactic penicillin regimens may be advisable for this population. This is an update of a Cochrane Review first published in 2002, and previously updated, most recently in 2014. OBJECTIVES: To assess the effects of antibiotic prophylaxis against pneumococcus in children with SCD in relation to:1. incidence of infection;2. mortality;3. drug-related adverse events (as reported in the included studies) to the individual and the community;4. the impact of discontinuing at various ages on incidence of infection and mortality. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, which is comprised of references identified from comprehensive electronic database searches and also two clinical trials registries: ClinicalTrials.gov and the WHO International Registry Platform. Additionally, we carried out handsearching of relevant journals and abstract books of conference proceedings.Date of the most recent search: 19 December 2016. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials comparing prophylactic antibiotics to prevent pneumococcal infection in children with SCD with placebo, no treatment or a comparator drug. DATA COLLECTION AND ANALYSIS: Both authors independently extracted data and assessed trial quality. The authors used the GRADE criteria to assess the quality of the evidence. MAIN RESULTS: Five trials were identified by the searches, of which three trials (880 children randomised) met the inclusion criteria. All of the included trials showed a reduced incidence of infection in children with SCD (SS or Sß0Thal) receiving prophylactic penicillin. In trials which investigated initiation of penicillin on risk of pneumococcal infection, the odds ratio was 0.37 (95% confidence interval 0.16 to 0.86) (two trials, 457 children) (low-quality evidence), while for withdrawal the odds ratio was 0.49 (95% confidence interval 0.09 to 2.71) (one trial, 400 children) (low-quality evidence). Adverse drug effects were rare and minor. Rates of pneumococcal infection were found to be relatively low in children over the age of five.Overall, the quality of the evidence for all outcomes was judged to be low. The results from the risk of bias assessment undertaken identified two domains in which the risk of bias was considered to be high, these were incomplete outcome data (attrition bias) (two trials) and allocation concealment (selection bias) (one trial). Domains considered to have a low risk of bias for all three trials were selective reporting (reporting bias) and blinding (performance and detection bias). AUTHORS' CONCLUSIONS: The evidence examined suggests that prophylactic penicillin significantly reduces risk of pneumococcal infection in children with homozygous SCD, and is associated with minimal adverse reactions. Further research may help to determine the ideal age to safely withdraw penicillin.

Ulcerative colitis in patients with sickle cell disease: a rare but important co-morbidity.

ABBREVIATIONS: COVID-19: Coronavirus disease 2019; HIC: high-income countries; IBD: inflammatory bowel disease; LMIC: low- and middle-income countries; PUCAL: paediatric ulcerative colitis activity index; SCD: sickle cell disease; UC: ulcerative colitis.

The additional genetic diagnosis of homozygous sickle cell disease in a patient with Waardenburg-Shah syndrome: a case report.

BACKGROUND: It is important that multiple genetic diagnoses are not missed. This case report describes the clinical features and management of a patient with co-inheritance of Waardenburg syndrome type 4 or Waardenburg-Shah syndrome, an extremely rare disease, and homozygous sickle cell disease not uncommon in the Caribbean. This case is unusual as it may be the first documented case of the co-inheritance of both these diseases. Given the commonality of sickle cell and related hemoglobinopathies, such combined disorders are likely to be under-reported. Importantly, reporting this case will add to the medical literature as it will raise awareness of the phenotypic manifestations of this disorder. CASE PRESENTATION: A 54-year-old Afro-Caribbean woman had a delayed diagnosis of homozygous sickle cell disease at 7 years of age by hemoglobin electrophoresis. The complications of sickle cell disease she experienced included bone pain, a chronic right leg ulcer, avascular necrosis of her left hip, and symptomatic cholelithiasis. This diagnosis was preceded by an earlier diagnosis of Waardenburg syndrome. The basis for the diagnosis of Waardenburg-Shah syndrome was the presence of pigmentary disturbances of her eyes (hypoplastic blue irides), congenital sensorineural hearing loss, and Hirschsprung's disease. She was mute and complained of chronic constipation which required disimpaction on several occasions. She attended a school for the deaf and communicated via writing. A Duhamel procedure bypassing her rectum was performed at age 9. She died following an admission for acute chest syndrome complications. CONCLUSION: Sickle cell disease can be diagnosed by newborn screening but, as in this case, may have a delayed presentation. The delay in diagnosis of homozygous sickle cell disease illustrates that other genetic disorders should be considered in patients who already have a diagnosis of one Mendelian disorder but show atypical features.

EXpanding Treatment for Existing Neurological Disease (EXTEND): An Open-Label Phase II Clinical Trial of Hydroxyurea Treatment in Sickle Cell Anemia.

BACKGROUND: Cerebral vasculopathy in sickle cell anemia (SCA) begins in childhood and features intracranial arterial stenosis with high risk of ischemic stroke. Stroke risk can be reduced by transcranial doppler (TCD) screening and chronic transfusion therapy; however, this approach is impractical in many developing countries. Accumulating evidence supports the use of hydroxyurea for the prevention and treatment of cerebrovascular disease in children with SCA. Recently we reported that hydroxyurea significantly reduced the conversion from conditional TCD velocities to abnormal velocities; whether hydroxyurea can be used for children with newly diagnosed severe cerebrovascular disease in place of starting transfusion therapy remains unknown. OBJECTIVE: The primary objective of the EXpanding Treatment for Existing Neurological Disease (EXTEND) trial is to investigate the effect of open label hydroxyurea on the maximum time-averaged mean velocity (TAMV) after 18 months of treatment compared to the pre-treatment value. Secondary objectives include the effects of hydroxyurea on serial TCD velocities, the incidence of neurological and non-neurological events, quality of life (QOL), body composition and metabolism, toxicity and treatment response, changes to brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), genetic and serologic markers of disease severity, and cognitive and pulmonary function. METHODS: This prospective Phase II trial will enroll children with SCA in Jamaica, between the ages of 2 and 17 years, with either conditional (170-199 cm/sec) or abnormal (≥ 200 cm/sec) TCD velocities. Oral hydroxyurea will be administered daily and escalated to the maximum tolerated dose (MTD). Participants will be seen in the Sickle Cell Unit (SCU) in Kingston, Jamaica monthly until achieving MTD, and then every 3 months. TCD will be performed every 6 months. RESULTS: Currently, 43 participants have been enrolled out of a projected 50. There was one withdrawal due to immigration, with no permanent screen failures. Of the 43 enrolled, 37 participants have initiated study treatment. CONCLUSIONS: This trial investigates the effects of hydroxyurea treatment at MTD in children with conditional or abnormal TCD velocities before transfusion therapy and may represent an important advance towards establishing a suitable non-transfusion protocol for stroke prevention in children with SCA. The trial outcomes will have profound significance in developing countries where the disease burden is highest. CLINICALTRIAL: ClinicalTrials.gov NCT02556099; https://clinicaltrials.gov/ct2/show/NCT02556099 (Archived by WebCite at http://www.webcitation.org/6k1yMAa9G).

Gangrene of the digits of the right lower limb in a patient with homozygous sickle cell disease and ulcerative colitis.

Thrombosis may play an important role in the pathophysiology of certain complications of sickle cell disease (SCD). While the association between SCD and ulcerative colitis (UC) is still debatable, inflammatory bowel disease is known to be associated with an increased incidence of thromboembolic disease. We report a case of a 16-year old girl known to have homozygous SCD and also diagnosed with UC who presented with digital ischemia of her right lower limb. This led to gangrene and subsequent amputation of the first, second and third digits of that limb. This case highlights that patients with both UC and SCD may have an increased risk of thromboembolism and raises the question as to whether patients with UC and SCD should be screened for thrombophilia.