Background Sickle cell anaemia (SCA) is associated with significant morbidity from acute complications and organ dysfunction beginning in the first year of life. In the first multicenter randomised double-blinded trial in very young children with SCA, the impact of hydroxyurea (hydroxycarbamide) therapy on organ dysfunction, clinical complications, and laboratory findings, and its toxicity, were examined. Methods Eligible subjects had HbSS or Sβ0thalassaemia, were age 9–18 months at randomisation, and were not selected for clinical severity. Subjects received liquid hydroxyurea, 20 mg/kg/day, or placebo for two years. Primary study endpoints were splenic function (qualitative uptake on 99Tc spleen scan) and renal function (glomerular filtration rate by 99mTc-DTPA clearance). Additional evaluations included: blood counts, HbF, chemistry profiles, spleen function biomarkers, urine osmolality, neurodevelopment, transcranial Doppler ultrasonography, growth, and mutagenicity. Study visits occurred every two to four weeks. Findings Ninety-six subjects received hydroxyurea and 97 placebo; 86% completed the study. Significant differences were not seen for the primary endpoints, but suggestive benefit was noted in quantitative measures of spleen function. Hydroxyurea significantly decreased pain and dactylitis with trends for decreased acute chest syndrome, hospitalisation and transfusion. Hydroxyurea increased haemoglobin and HbF and decreased WBC count. Toxicity was limited to mild-moderate neutropaenia. Interpretation Although hydroxyurea treatment did not reduce splenic and renal dysfunction assessed by primary endpoint measures, it resulted in major clinical benefit because of diminished acute complications, favorable haematologic results, and a lack of unexpected toxicities. Based on the safety and efficacy data from this trial, hydroxyurea can now be considered for all very young children with SCA.

BACKGROUND Silent cerebral infarcts are the most common neurologic injury in children with sickle cell anemia and are associated with the recurrence of an infarct (stroke or silent cerebral infarct). We tested the hypothesis that the incidence of the recurrence of an infarct would be lower among children who underwent regular blood-transfusion therapy than among those who received standard care. METHODS In this randomized, single-blind clinical trial, we randomly assigned children with sickle cell anemia to receive regular blood transfusions (transfusion group) or standard care (observation group). Participants were between 5 and 15 years of age, with no history of stroke and with one or more silent cerebral infarcts on magnetic resonance imaging and a neurologic examination showing no abnormalities corresponding to these lesions. The primary end point was the recurrence of an infarct, defined as a stroke or a new or enlarged silent cerebral infarct. RESULTS A total of 196 children (mean age, 10 years) were randomly assigned to the observation or transfusion group and were followed for a median of 3 years. In the transfusion group, 6 of 99 children (6%) had an end-point event (1 had a stroke, and 5 had new or enlarged silent cerebral infarcts). In the observation group, 14 of 97 children (14%) had an end-point event (7 had strokes, and 7 had new or enlarged silent cerebral infarcts). The incidence of the primary end point in the transfusion and observation groups was 2.0 and 4.8 events, respectively, per 100 years at risk, corresponding to an incidence rate ratio of 0.41 (95% confidence interval, 0.12 to 0.99; P = 0.04). CONCLUSIONS Regular blood-transfusion therapy significantly reduced the incidence of the recurrence of cerebral infarct in children with sickle cell anemia. (Funded by the National Institute of Neurological Disorders and Stroke and others; Silent Cerebral Infarct Multi-Center Clinical Trial ClinicalTrials.gov number, NCT00072761, and Current Controlled Trials number, ISRCTN52713285.)

Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).

Background For children with sickle cell anaemia and elevated transcranial Doppler (TCD) flow velocities, regular blood transfusions effectively prevent primary stroke, but must be continued indefinitely. The efficacy of hydroxyurea in this setting is unknown. Methods TWiTCH was a multicentre Phase III randomised open label, non-inferiority trial comparing standard treatment (transfusions) to alternative treatment (hydroxyurea) in children with abnormal TCD velocities but no severe vasculopathy. Iron overload was managed with chelation (Standard Arm) and serial phlebotomy (Alternative Arm). The primary study endpoint was the 24-month TCD velocity calculated from a general linear mixed model, with non-inferiority margin = 15 cm/sec. Findings Among 121 randomised participants (61 transfusions, 60 hydroxyurea), children on transfusions maintained <30% sickle haemoglobin, while those taking hydroxyurea (mean 27 mg/kg/day) averaged 25% fetal haemoglobin. The first scheduled interim analysis demonstrated non-inferiority, and the sponsor terminated the study. Final model-based TCD velocities (mean ± standard error) on Standard versus Alternative Arm were 143 ± 1.6 and 138 ± 1.6 cm/sec, respectively, with difference (95% CI) = 4.54 (0.10, 8.98), non-inferiority p=8.82 × 10−16 and post-hoc superiority p=0.023. Among 29 new neurological events adjudicated centrally by masked reviewers, no strokes occurred but there were 3 transient ischaemic attacks per arm. Exit brain MRI/MRA revealed no new cerebral infarcts in either arm, but worse vasculopathy in one participant (Standard Arm). Iron burden decreased more in the Alternative Arm, with ferritin difference −1047 ng/mL (−1524, −570), p<0.001 and liver iron difference −4.3 mg Fe/gm dry weight (−6.1, −2.5), p=0.001. Interpretation For high-risk children with sickle cell anaemia and abnormal TCD velocities, after four years of transfusions and without severe MRA vasculopathy, hydroxyurea therapy can substitute for chronic transfusions to maintain TCD velocities and help prevent primary stroke.

Children with sickle cell disease (SCD) and strokes receive blood transfusion therapy for secondary stroke prevention; despite this, approximately 20% experience second overt strokes. Given this rate of second overt strokes and the clinical significance of silent cerebral infarcts, we tested the hypothesis that silent cerebral infarcts occur among children with SCD being transfused for secondary stroke prevention. A prospective cohort enrolled children with SCD and overt strokes at 7 academic centers.

The most common form of neurologic injury in sickle cell anemia (SCA) is silent cerebral infarction (SCI). In the Silent Cerebral Infarct Multi-Center Clinical Trial, we sought to identify risk factors associated with SCI. In this cross-sectional study, we evaluated the clinical history and baseline laboratory values and performed magnetic resonance imaging of the brain in participants with SCA (HbSS or HbS␤°thalassemia) between the ages of 5 and 15 years with no history of overt stroke or seizures. Neuroradiology and neurology committees adjudicated the presence of SCI. SCIs were diagnosed in 30.8% (251 of 814) participants who completed all evaluations and had valid data on all prespecified demographic and clinical covariates. The mean age of the participants was 9.1 years, with 413 males (50.7%). In a multivariable logistic regression analysis, lower baseline hemoglobin concentration (P < .001), higher baseline systolic blood pressure (P ‫؍‬ .018), and male sex (P ‫؍‬ .030) were statistically significantly associated with an increased risk of an SCI. Hemoglobin concentration and systolic blood pressure are risk factors for SCI in children with SCA and may be therapeutic targets for decreasing the risk of SCI. This study is registered at www.clinicaltrials.gov as #NCT00072761. IntroductionSilent cerebral infarcts (SCIs) have been recognized by neuroimaging in neurologically normal older adult populations since 1981 1 and were documented in sickle cell anemia (SCA) soon afterward. 2 As with overt stroke, SCIs represent a clinical finding that is common in older adults without SCD, but they appear during early childhood in persons with SCA. SCIs are defined as an MRI signal abnormality visible on 2 views on the T2-weighted images (axial and coronal) that must measure at least 3 mm in one dimension; further, the person deemed to have an SCI must have an absence of focal neurologic deficit compatible with the anatomic location of the brain lesion. 3 SCI is the most common form of neurologic injury among children with SCA, occurring in at least 27% before 6 years of life 4 and 37% by 14 years of life. 5 SCIs in children with SCA are associated with increased risk of future overt strokes and new or progressive SCIs. 6,7 In addition, children with SCA and SCI have been found to have poorer cognitive function The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked ''advertisement'' in accordance with 18 USC section 1734. 3684BLOOD, 19 APRIL 2012 ⅐ VOLUME 119, NUMBER 16For personal use only. on March 28, 2019. by guest www.bloodjournal.org From than children with SCA with normal MRI of the brain 8-10 or sibling controls. 10,11 Clinical and laboratory risk factors for SCI have been evaluated only sparingly. In the most rigorous study to date, the investigators from the Cooperative Study for Sickle Cell Disease (CSSCD) described risk factors associated with SCI in 42 participants, comparing them with 188 controls with ...

Sickle cell trait (SCT) carries a small risk of renal medullary carcinoma (RMC). We conducted a systematic literature review and reported new four RMC cases (total N = 217). Eighty eight percent had SCT and 8% had sickle cell disease; 50% were children. Males had 2.4× risk than females. Isolated hematuria or in combination with abdominal or flank pain was the presenting sign in 66% cases. Tumor-related mortality was 95%. Four non-metastatic patients were long-term disease-free survivors. Although risk appears to be very low, individuals with SCT should be informed about the low risk of RMC with the hope of early diagnosis. Hematuria should prompt immediate investigation.

Renal involvement is common in homozygous sickle cell disease (HbSS), including glomerular hypertension and hypertrophy similar to that seen in rodent models of ablative nephrectomy and stage I diabetic nephropathy (DN). The proteinuria in the rodent models is attenuated by angiotensin converting enzyme inhibition (ACEI). Microalbuminuria (MA) is a sensitive marker for renal involvement in DN prior to the development of proteinuria, and is also attenuated with ACEI. Elevated urinary microalbumin/creatinine ratios (U Alb/Cr) >20 mg/g Cr are reported in 39%-43% of adults with HbSS, and studies are ongoing in this age group to assess the effect of attenuated proteinuria by ACEI on long-term renal function. The purpose of this study was to prospectively investigate the prevalence of MA in children with HbSS and determine factors which affect its expression. U Alb/Cr values were measured on spot urine samples in 102 children (aged 2-18 years, mean 9.47+/-4.62, M:F=53:49) by rate nephelometry. Children with prior known proteinuria, hypertension, or fever/pain episode in the last 15 days were excluded. MA was present in 26.5% of all children with HbSS. However, in children between the ages of 10 and 18 years, the prevalence was 46% (similar to the prevalence in adults). There was a strong correlation between patient age and prevalence of MA (P<0.0001) by both univariate and multivariate analysis. However, pain frequency, hospitalization, transfusion program, ferritin levels, and Cr clearance (C(Cr)) did not correlate with prevalence, although C(Cr) (as estimated by Schwartz formula) was elevated in all. We conclude that the prevalence of MA in the 2nd decade of life is similar to that in adults.