Novel CUBN Mutation in a Young Child With Megaloblastic Anemia.

Inherited disorders of cobalamin (Cbl, vitamin B12) metabolism are rare causes of megaloblastic anemia and neurologic abnormalities. More prevalent in certain ethnic groups, these disorders occur despite adequate Cbl intake and usually result from abnormal vitamin cell transport or processing. Cubilin (CUBN, intrinsic factor-cobalamin receptor) is the intestinal receptor for the endocytosis of intrinsic factor-vitamin B12. Its gene is localized to chromosome 10p13 and mutations involving CUBN have been described in patients with congenital megaloblastic anemia. In this report, we describe a novel CUBN pathogenic variant in a child with megaloblastic anemia.

Outcomes of Isolated Neutropenia Referred to Pediatric Hematology-Oncology Clinic.

BACKGROUND: Children with isolated neutropenia (absolute neutrophil count [ANC] <1500/µL) are frequently referred to pediatric hematology and oncology clinics for further diagnostic evaluation. Scant literature exists on interventions and outcomes for isolated neutropenia. We hypothesized that children will have resolution of their neutropenia without the need for intervention(s) by a pediatric hematologist and oncologist. METHODS: We performed a 5.5-year institutional review board-approved retrospective chart review of children referred to our pediatric hematology and oncology clinics for isolated neutropenia. Neutropenia was categorized as mild (ANC of 1001-1500/µL), moderate (ANC of 500-1000 µL), severe (ANC of 201-500/µL), or very severe (ANC of ≤200/µL). RESULTS: Among 155 children referred with isolated neutropenia, 45 (29%) had mild neutropenia, 65 (42%) had moderate neutropenia, 30 (19%) had severe neutropenia, and 15 (10%) had very severe neutropenia. Only 29 (19%) children changed to an ANC category lower than their initial referral category. At a median follow-up of 12 months, 101 children had resolution of neutropenia, 40 children had mild neutropenia, 10 children had moderate neutropenia, 3 children had severe neutropenia, and 1 patient had very severe neutropenia. A specific diagnosis was not identified in most (54%) children. The most common etiologies were viral suppression (16%), autoimmune neutropenia (14%), and drug-induced neutropenia (8%). Black children had a 3.5 higher odds of having persistent mild neutropenia. Six (4%) children received granulocyte colony-stimulating factor therapy. CONCLUSIONS: Most children referred for isolated neutropenia do not progress in severity and do not require subspecialty interventions or hospitalizations.

Impact of early analgesia on hospitalization outcomes for sickle cell pain crisis.

BACKGROUND: Painful events are the leading cause of hospitalizations for patients with sickle cell disease. Individualized pain plans targeting patient-specific maximum opioid dosing may shorten hospitalization length and are recommended by national guidelines. Prior to implementing individualized sickle cell pain plans, we tested the hypothesis that a shorter time to achieve a maximum opioid dose would improve hospitalization outcomes. PROCEDURE: Two-year IRB-approved, retrospective study of pediatric patients admitted for vaso-occlusive crisis (VOC). We recorded the emergency department admission time, order entry time for the maximum opioid dose during the hospitalization, and time of discharge orders.  We categorized patients as infrequent if they required <3 admissions for VOC over two years and patients as frequent if they required ≥3 admissions for VOC over two years. To account for multiple admissions, generalized linear modeling was performed. RESULTS: We identified 236 admissions for acute pain observed in 108 patients. Achieving an earlier maximum opioid dose was significantly associated with shorter length of hospitalization for frequent and infrequent pain patients (both P ≤ 0.0001). As total hospitalization length can be impacted by the time a maximum opioid order was placed, we also analyzed hospitalization length after the maximum opioid order was placed. Frequent pain patients who achieved earlier analgesia had a significantly shorter hospitalization from the time the maximum opioid order was placed (P = 0.03) while no association was found for infrequent pain patients (P = 0.84). CONCLUSIONS: Early achievement of maximum analgesia improved hospitalization outcomes and warrant further investigation in prospective studies of individualized pain plans.

Red blood cell transfusion therapy for sickle cell patients with frequent painful events.

BACKGROUND: Recurrent pain events or chronic pain are among the most common complications of sickle cell disease. Despite attempts to maximize adherence to and dosing of hydroxyurea, some patients continue to suffer from pain. Our institution developed a program to initiate chronic red blood cell transfusions for one year in patients clinically deemed to have high healthcare utilization from sickle cell pain, despite being prescribed hydroxyurea. PROCEDURE: An institutional review board approved retrospective study to evaluate the health outcomes associated with a one-year red blood cell transfusion protocol in sickle cell patients experiencing recurrent pain events as compared with the health outcomes for these patients in the one year prior to receiving transfusion therapy. We performed a matched-pair analysis using a Wilcoxon signed rank to determine the impact of transfusion therapy on clinic visits, emergency department visits, hospital admissions, hospitalization days, and opioid prescriptions filled. RESULTS: One year of transfusion therapy significantly reduced the number of total emergency department visits for pain (6 vs 2.5 pain visits/year, P = 0.005), mean hospitalizations for pain (3.4 vs 0.9 pain admissions/year), and mean hospital days per year for pain crisis (23.5 vs 4.5, P = 0.0001), as compared with the one year prior to transfusion therapy. We identified no significant difference in opioid prescriptions filled during the year of transfusion therapy. CONCLUSION: Patients with frequent pain episodes may benefit from one year of transfusion therapy.

Management of severe chronic pain with methadone in pediatric patients with sickle cell disease.

Vasocclusive pain crises are common among pediatric patients with sickle cell disease (SCD). Some patients with repeated pain crises develop chronic pain. We performed a retrospective cohort study of pediatric patients with SCD with chronic pain treated with methadone. We identified a significant reduction in pain hospitalizations following methadone treatment (0.35 ± 0.19 vs. 0.19 ± 0.17 hospitalizations/month, P = 0.016). In addition, we did not observe overt organ toxicity nor symptoms of opioid withdrawal during methadone wean. We suggest that methadone is safe and has some clinical benefit, which should be proven in prospective randomized trials for pediatric patients with SCD and chronic pain.

Evaluating risk factors for chronic kidney disease in pediatric patients with sickle cell anemia.

BACKGROUND: Patients with sickle cell anemia (SCA) have an increased prevalence of nephropathy and mortality from chronic kidney disease (CKD). METHODS: We evaluated the association of hyperuricemia and nocturnal hypertension with lower estimated glomerular filtration rate (eGFR) using cystatin-C in patients aged 10-21 years with the HbSS or HbSB0 form of the disease during a non-acute clinic visit. eGFR and uric acid measurements were obtained in 83 and 81 participants, respectively, and 24-h ambulatory blood pressure monitoring (ABPM) was performed in 44 participants. Annual testing included vital signs, complete blood count, comprehensive metabolic panel, medications, urine microalbumin/creatinine, and lactate dehydrogenase measurements. Hyperuricemia was defined as a uric acid level of ≥5.5 mg/dL. Nocturnal hypertension was defined as >25% of nocturnal readings at >95th percentile according to norms established by the American Heart Association Statement on ABPM in children and adolescents. RESULTS: The mean eGFR was statistically significantly lower in patients with hyperuricemia than in those with normal uric acid levels (143 vs. 161 mL/min/1.73 m2, respectively). Of the 44 participants for whom ABPM data were available, 14 (32%) had systolic nocturnal hypertension and 12 (27%) had diastolic nocturnal hypertension. The mean eGFR was statistically significantly lower in participants with nocturnal systolic and diastolic hypertension than in those with normal nocturnal blood pressure. In a regression model, nocturnal hypertension and hyperuricemia were associated with a lower eGFR. CONCLUSIONS: Two risk factors for CKD, i.e., nocturnal hypertension and hyperuricemia, were associated with lower eGFR in older children and adolescent patients with SCA. Long-term studies on their association with progression to CKD in this population are warranted. KEY POINT: Nocturnal hypertension and hyperuricemia are established risk factors for nephropathy in other diseases and may play a role in SCA nephropathy.

Elective cholecystectomy reduces morbidity of cholelithiasis in pediatric sickle cell disease.

BACKGROUND: Cholelithiasis is a frequent complication in pediatric sickle cell disease (SCD). Though it is standard practice to perform a cholecystectomy in pediatric SCD patients with symptoms of cholelithiasis, the use of elective cholecystectomy for asymptomatic patients remains controversial. PROCEDURE: Records of 191 pediatric sickle cell patients with cholelithiasis who underwent cholecystectomy were retrospectively reviewed. Patients classified as follows: (i) elective-no preoperative symptoms, cholelithiasis on screening ultrasound, comprehensive preoperative plan; (ii) symptomatic-preoperative symptoms of cholelithiasis on diagnostic ultrasound, comprehensive preoperative plan; or (iii) emergent-hospitalization for acute cholecystitis symptoms, cholelithiasis on diagnostic ultrasound, limited preoperative preparation. We compared the morbidity of cholecystectomy by examining pre- and post-cholecystectomy hospital admission days, length of stay for cholecystectomy, and surgical complications. RESULTS: Patients with SCD underwent a total of 191 cholecystectomies over a 10-year period: 51 elective, 110 symptomatic, and 30 emergent. Patients who required emergent cholecystectomy had a longer postoperative hospitalization time than elective or symptomatic cholecystectomy (7.3 vs 4.3, P < 0.001). Baseline values for total bilirubin and aspartate aminotransferase (AST) were significantly elevated (P < 0.02 and P < 0.07, respectively) in patients requiring emergent cholecystectomy. CONCLUSIONS: This represents the largest reported retrospective review of pediatric cholelithiasis and cholecystectomy in SCD to date. These data strongly suggest that elective cholecystectomy decreases morbidity associated with emergent cholecystectomy. The overall outcomes for symptomatic and elective patients are favorable. However, our study indicates the need for prospective studies to identify clinical indicators for those emergent patients.

Prevalence of acute kidney injury during pediatric admissions for acute chest syndrome.

BACKGROUND: Patients with sickle cell disease are at risk for developing chronic kidney disease (CKD). Acute kidney injury (AKI) has been linked to progression to CKD, but limited data exist to determine its role in acute complications of sickle cell disease. We hypothesized that AKI occurs in pediatric patients admitted for acute chest syndrome (ACS) and prolongs hospitalization. METHODS: We conducted a 6-year retrospective review of pediatric patients with ACS admitted to a single medical institution. RESULTS: Of the 149 pediatric patients admitted for ACS during the 6-year study period, 12 (8 %) developed AKI. Comparison of patients with and without AKI revealed a significant association between AKI and a larger drop in hemoglobin value from baseline (2.7 vs. 1.4 g/dL; p = 0.003), a lower hemoglobin value at admission (6.4 vs. 7.5 g/dL; p = 0.03), and an increased white blood cell count at admission (33.1 vs. 19.8 × 10(9)/L; p < 0.0001), respectively. AKI (p < 0.0001) together with need for advanced respiratory support (biphasic positive airway pressure or mechanical ventilation) (p < 0.0001) and need for exchange transfusion (p < 0.0001) were associated with prolonged hospitalization. CONCLUSIONS: Clinicians should monitor pediatric patients hospitalized for ACS for the development of AKI as a potentially modifiable risk factor for prolonged hospitalization.

Pharmacokinetics and bioequivalence of a liquid formulation of hydroxyurea in children with sickle cell anemia.

Hydroxyurea (HU) is a crucial therapy for children with sickle cell anemia, but its off-label use is a barrier to widespread acceptance. We found HU exposure is not significantly altered by liquid vs capsule formulation, and weight-based dosing schemes provide consistent exposure. HU is recommended for all children starting as young as 9 months of age with sickle cell anemia (SCA; HbSS and HbSßspan(0) thalassemia); however; a paucity of pediatric data exists regarding the pharmacokinetics (PK) or the exposure-response relationship of HU. This trial aimed to characterize the PK of HU in children and to evaluate and compare the bioavailability of a liquid vs capsule formulation. This multicenter; prospective; open-label trial enrolled 39 children with SCA who provided 682 plasma samples for PK analysis following administration of HU. Noncompartmental and population PK models are described. We report that liquid and capsule formulations of HU are bioequivalent; weight-based dosing schemes provide consistent drug exposure; and age-based dosing schemes are unnecessary. These data support the use of liquid HU in children unable to swallow capsules and in those whose weight precludes the use of fixed capsule formulations. Taken with existing safety and efficacy literature; these findings should encourage the use of HU across the spectrum of age and weight in children with SCA; and they should facilitate the expanded use of HU as recommended in the National Heart; Lung; and Blood Institute guidelines for individuals with SCA.

Systematic review of interventional sickle cell trials registered in ClinicalTrials.gov.

BACKGROUND/AIMS: The registry ClinicalTrials.gov was created to provide investigators and patients an accessible database of relevant clinical trials. METHODS: To understand the state of sickle cell disease clinical trials, a comprehensive review of all 174 "closed," "interventional" sickle cell trials registered at ClinicalTrials.gov was completed in January 2015. RESULTS: The majority of registered sickle cell disease clinical trials listed an academic center as the primary sponsor and were an early phase trial. The primary outcome for sickle cell disease trials focused on pain (23%), bone marrow transplant (BMT) (13%), hydroxyurea (8%), iron overload (8%), and pulmonary hypertension (8%). A total of 52 trials were listed as terminated or withdrawn, including 25 (14% of all trials) terminated for failure to enroll participants. At the time of this review, only 19 trials uploaded results and 29 trials uploaded a manuscript in the ClinicalTrials.gov database. A systematic review of pubmed.gov revealed that only 35% of sickle cell studies completed prior to 2014 resulted in an identified manuscript. In comparison, of 80 thalassemia trials registered in ClinicalTrials.gov, four acknowledged failure to enroll participants as a reason for trial termination or withdrawal, and 48 trials (60%) completed prior to 2014 resulted in a currently identified manuscript. CONCLUSION: ClinicalTrials.gov can be an important database for investigators and patients with sickle cell disease to understand the current available research trials. To enhance the validity of the website, investigators must update their trial results and upload trial manuscripts into the database. This study, for the first time, quantifies outcomes of sickle cell disease trials and provides support to the belief that barriers exist to successful completion, publication, and dissemination of sickle cell trial results.

Encephaloduroarteriosynangiosis and encephalomyoarteriosynangiosis for treatment of moyamoya syndrome in pediatric patients with sickle cell disease.

OBJECT Pediatric patients with sickle cell disease (SCD) and moyamoya syndrome (MMS) are at significant risk for cerebrovascular accidents despite chronic transfusion therapy. Encephaloduroarteriosynangiosis (EDAS) and encephalomyoarteriosynangiosis (EMAS) are additional therapeutic options for these patients. To date, the incidence of complications after and efficacy of EDAS and EMAS in stroke prevention in this population have been described in several institutional case series reports, but no randomized prospective trials have been reported. METHODS The authors retrospectively reviewed the cases of all pediatric patients at the University of Alabama at Birmingham with a history of homozygous hemoglobin S (HbS) and sickle cell/ß-thalassemia (SB0 thalassemia) and on chronic transfusion therapy, including 14 patients with MMS who underwent EDAS or EMAS. RESULTS Sixty-two patients with SCD and on chronic transfusion therapy were identified. After exclusion of patients on chronic transfusion therapy for indications other than stroke prevention, 48 patients (77.4%) remained. Of those patients, 14 (29.1%) underwent EDAS or EMAS. Nine (18.8%) and 25 (52.1%) patients were on chronic transfusion therapy for primary or secondary stroke prevention, respectively, but did not undergo EDAS or EMAS. The 14 patients with SCD and radiological evidence of MMS and on chronic transfusion therapy for primary or secondary stroke prevention underwent 21 EDAS or EMAS procedures for progressive vascular disease (92.9% of patients), stroke (71.4%), and/or seizure (7.1%). The mean (± SD) time from initiation of chronic transfusion therapy to EDAS or EMAS was 76.8 ± 58.8 months. Complications included 1 perioperative stroke, 1 symptomatic subdural hygroma, 1 postoperative seizure, and 1 case of intraoperative cerebral edema that required subsequent cranioplasty. Before EDAS or EMAS, the stroke rate was calculated to be 1 stroke per 7.8 patient-years. One additional stroke occurred during the follow-up period (mean follow-up time 33.7 ± 19.6 months), resulting in a post-EDAS/EMAS stroke rate of 1 stroke per 39.3 patient-years, a 5-fold reduction compared with that in the pre-EDAS/EMAS period. The patients' mean pre-EDAS/EMAS HbS level of 29.5% ± 6.4% was comparable to the mean post-EDAS/EMAS HbS level of 25.5% ± 6.1% (p = 0.104). CONCLUSIONS The results of this retrospective case series in a large cohort of pediatric patients with SCD and MMS suggest that EDAS/EMAS provides a stroke-prevention benefit with an acceptably low morbidity rate. Given the combined experience with EDAS and EMAS for this indication at this and other institutions, a prospective clinical trial to assess their efficacy compared with that of chronic transfusion therapy alone is warranted.

Hydroxyurea decreases hospitalizations in pediatric patients with Hb SC and Hb SB+ thalassemia.

PURPOSE: Patients with hemoglobin SC (Hb SC) and hemoglobin SB+ (Hb SB+) thalassemia suffer from frequent hospitalizations yet strong evidence of a clinical benefit of hydroxyurea (HU) in this population is lacking. Patients with recurrent hospitalizations for pain crisis are offered HU at our institution based on small cohort data and anecdotal benefit. This study identifies outcomes from a large cohort of patients with Hb SC and SB+ thalassemia who were treated with HU for 2 years. MATERIALS AND METHODS: A retrospective review was conducted of 32 patients with Hb SC and SB+ thalassemia who were treated with HU. We reviewed the number, and reasons for hospitalization in the 2 years prior to, and 2 years post-HU treatment as well as laboratory changes from baseline, over 1 year. RESULTS: Patients with Hb SC and SB+ thalassemia started on HU for frequent pain, had a significant reduction in hospitalizations over 2 years as compared to the 2 years prior to HU initiation (mean total hospitalizations/year: pre-HU: 1.6 vs post-HU 0.4 hospitalizations, P<0.001; mean pain hospitalizations/year: pre-HU 1.5 vs post-HU 0.3 hospitalizations, P<0.001). Patients demonstrated hematologic changes including an increase in percent fetal hemoglobin (%HbF) pre-post HU (4.5% to 7.7%, P=0.002), mean corpuscular volume (74 to 86 fL, P<0,0001), and decrease in absolute neutrophil count (5.0 to 3.2×10(9)/L, P=0.007). Patients with higher doses of HU demonstrated the greatest reduction in hospitalizations but this was unrelated to absolute neutrophil count. CONCLUSION: This cohort of patients with Hb SC and SB+ thalassemia provides additional support for using HU in patients with recurrent hospitalizations for pain. A large randomized multicenter trial of HU to reduce pain admissions should be conducted to confirm these data and provide much needed evidence based recommendations for this population.

Patient-centered approach to designing sickle cell transition education.

INTRODUCTION: It is vital to engage patients with sickle cell disease (SCD) in the transition process from pediatric to adult care. To better understand the patient perspective during the time of transition, we conducted this research with the goal of incorporating patient comprehension and desires for transition education. MATERIALS AND METHODS: We surveyed 37 adolescent patients with SCD about their understanding of SCD and transition education preferences. In addition, patient responses were analyzed to understand differences among urban and rural patients. RESULTS: The mean age of surveyed participants was 14.9 years (SD=2.1). Forty-three percent of participants responded that the topic of transition had been introduced to them, and only 21% responded that they received education about transition. Despite the poor awareness about transition, almost all participants were interested in learning more about the transition process through a technology-based transition education platform where individual health topics could be explored. DISCUSSION: Despite a didactic teaching approach to transition education, we identified that sickle cell participants had poor recognition of receiving transition education and poor understanding of their basic medical history. However, patients can identify specific health topics that should be addressed during an individualized transition education program.

Controlled trial of transfusions for silent cerebral infarcts in sickle cell anemia.

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.).

Silent cerebral infarction, income, and grade retention among students with sickle cell anemia.

Children with sickle cell anemia have a higher-than-expected prevalence of poor educational attainment. We test two key hypotheses about educational attainment among students with sickle cell anemia, as measured by grade retention and use of special education services: (1) lower household per capita income is associated with lower educational attainment; (2) the presence of a silent cerebral infarct is associated with lower educational attainment. We conducted a multicenter, cross-sectional study of cases from 22 U.S. sites included in the Silent Infarct Transfusion Trial. During screening, parents completed a questionnaire that included sociodemographic information and details of their child's academic status. Of 835 students, 670 were evaluable; 536 had data on all covariates and were used for analysis. The students' mean age was 9.4 years (range: 5-15) with 52.2% male; 17.5% of students were retained one grade level and 18.3% received special education services. A multiple variable logistic regression model identified that lower household per capita income (odds ratio [OR] of quartile 1 = 6.36, OR of quartile 2 = 4.7, OR of quartile 3 = 3.87; P = 0.001 for linear trend), age (OR = 1.3; P < 0.001), and male gender (OR, 2.2; P = 0.001) were associated with grade retention; silent cerebral infarct (P = 0.31) and painful episodes (P = 0.60) were not. Among students with sickle cell anemia, household per capita income is associated with grade retention, whereas the presence of a silent cerebral infarct is not. Future educational interventions will need to address both the medical and socioeconomic issues that affect students with sickle cell anemia.

Exploring barriers and facilitators to clinical trial enrollment in the context of sickle cell anemia and hydroxyurea.

BACKGROUND: Several sickle cell clinical trials have closed due to inability to enroll patients. To limit the early cessation of a proposed clinical trial due to low accrual rates, we sought to better understand barriers and facilitators to enrolling parents of children with sickle cell anemia (SCD) into clinical trials. PROCEDURE: Focus groups (n = 3) were conducted with parents/guardians (n = 14) who had not previously been recruited for a clinical trial and were not administering hydroxyurea to their children. RESULTS: Three main themes related to barriers to clinical trial enrollment were identified during analysis of focus groups: general barriers to health related research (general mistrust of research studies, emotional and practical concerns), barriers to trial design (randomization), and barriers to hydroxyurea (long term unknown risks, cancer, myelosuppressive effects). Facilitators identified were need for more education, including request for peer education, and improved explanation of clinical trials or study rationale. CONCLUSION: Engagement of parents/guardians of children with SCD in identifying barriers and facilitators to clinical trial enrollment may be critical to the development of strategies to enhance SCD trial completion.

Barriers in transition from pediatrics to adult medicine in sickle cell anemia.

Transition of care from pediatric to adult providers is an essential step in the care of young adults with sickle cell anemia. Transition programs should be developed by individual institutions to systematically enhance the transition process for their patients. Prior to transfer, patients must be educated about their disease and personal medical history and develop skill sets required to navigate the adult health care setting. The objective of this literature review is to identify key concepts associated with transition of care for patients with sickle cell anemia. First, transition programs should be developed so that education about transition can begin at an early age. The readiness of patients and families should be assessed and education tailored to meet individual patient needs. Finally, the emotions and fears about transition should be recognized and addressed prior to transition.

Associated risk factors for silent cerebral infarcts in sickle cell anemia: low baseline hemoglobin, sex, and relative high systolic blood pressure.

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 HbSß° 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.