Neuropsychologic impairment in children with sickle cell anemia

In this study, the neuropsychologic functioning of 21 children with sickle cell anemia and 21 sibling controls, age range 7 through 16 years, with no history of neurologic disease, was examined. Outcome measures included tests of intelligence, constructional praxis, memory, and academic learning. On the Wechsler Intelligence Scale for Children--Revised, the sickle cell group had a mean Full Scale IQ of 77.7 (SD 12.4) compared with 94.3 (SD 11.0) for the control group. The profile of test scores was similar for the two groups, with the sickle cell group scoring significantly lower than the control group on almost all cognitive measures. Both groups showed academic achievement to be commensurate with their measured intellectual ability. These results suggest that subtle but significant and widespread neuropsychologic deficits are associated with sickle cell anemia even in the absence of neurologic complications. When and by what process this neuropsychologic impairment is caused needs to be determined.     

Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia.

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.     

Hydroxyurea use among children with sickle cell anemia

This study describes hydroxyurea use among children ages 1 to 17 with sickle cell anemia (SCA) enrolled in at least one year of Medicaid in six states from 2005 to 2012. Administrative claims were used to summarize the number of days’ supply of hydroxyurea dispensed by state and year. A total of 7963 children with SCA contributed 22 424 person‐years. Among person‐years with greater than 30 days of hydroxyurea, only 18% received at least 300 days of hydroxyurea, which varied by state. Following updated recommendations for all children with SCA to be offered hydroxyurea, strategies to increase hydroxyurea adherence among this population are needed.     

Longitudinal exercise hemodynamics in children with sickle cell anemia

To define further the natural history and causative factors in exercise-related cardiac dysfunction in children and adolescents with sickle cell anemia (SS), we studied the results of 74 patients' initial and follow-up exercise tests. The follow-up study was done one to three years after the first study in 36 children and four to seven years after initial testing in 38 children. Split-plot analysis of covariance did not show any temporal deterioration in exercise hemodynamic variables. Correlation analysis defined hemoglobin and hematocrit levels as critical determinants of cardiac functional reserve capacity in these patients. Several exercise ECG patterns, formerly considered abnormal in children with SS, are now considered to be variants of normal. Studies are presently in progress that should further define the nature and severity of the cardiac impairment during exercise in children with SS.     

Bone mineral density in children with sickle cell anemia

PURPOSE: We evaluated bone mineral density (BMD) and risk factors for poor bone mineralization in children with sickle cell anemia (SCA). PATIENTS AND METHODS: Twenty-five children with severe manifestations of SCA (frequent hospitalizations, growth delay, or need for chronic red cell transfusions) were enrolled. Bone density was assessed at lumbar spine and proximal femur with dual-energy X-ray absorptiometry (DXA), and Z-scores were calculated by comparison with age, sex, and ethnicity-specific reference data. RESULTS: The median age of the study population was 12.8 years (10.2-19.8 years). Calcium intake was inadequate in 60%, and serum 25-hydroxy vitamin D (25-OHD) level <50 nM in 74% of patients. Median Z-scores for lumbar spine (-2.3) and proximal femur (-1.7) were markedly reduced, and 64% (95% confidence interval, 43%-82%) of patients had low bone density. Z-scores were not related to age, growth delay, chronic transfusions, or ferritin level. CONCLUSION: Our results suggest that children with severe manifestations of SCA have low BMD, and possess significant deficits in dietary calcium and circulating vitamin D.     

Risk factors for microalbuminuria in children with sickle cell anemia

PURPOSE: To determine the prevalence of microalbuminuria and to establish clinical characteristics associated with microalbuminuria in children with sickle cell anemia. PATIENTS AND METHODS: Urine samples of all children (homozygous SS) followed in the Medical College of Georgia's Children's Medical Center Sickle Cell Clinic were screened for microalbuminuria. Random samples were obtained from continent patients at routine office visits between September 1996 and November 1999. A retrospective chart survey was performed to determine clinical correlates for microalbuminuria. Medical records were reviewed for age, sex, hemoglobin, and episodes of pneumonia, pain, aplasia, acute chest syndrome, priapism, and avascular necrosis. Demographic and clinical variables were compared with microalbuminuria by univariate and multivariate logistic regression. RESULTS: One hundred forty-two patients ages 21 months to 20 years made up the study group. The prevalence of microalbuminuria was 19%. Both increasing age and a lower hemoglobin level were found to correlate with microalbuminuria. By multivariate analysis, boys with microalbuminuria were likely to have a lower hemoglobin level and girls with microalbuminuria were likely to be older. None of the following factors were significantly related to microalbuminuria: pain, pneumonia, acute chest syndrome, priapism, avascular necrosis, or aplastic episodes. CONCLUSIONS: Microalbuminuria is strongly and directly related to age and strongly and inversely related to hemoglobin levels. Identification of risk factors for microalbuminuria may allow earlier intervention to prevent renal complications in patients with sickle cell disease.     

Obesity--does it occur in Nigerian children with sickle cell anemia

Children with sickle cell anemia are vulnerable to growth deficits; thus, it would be thought that obesity would be rare among them. The objective of the study is to examine the prevalence of obesity in a sickle cell anemia population in Lagos. A random sample of children with sickle cell anemia aged 2-15 years was interviewed and anthropometric measurements including weight and height were taken. Their body mass index (BMI) was calculated. Participants were classified as obese or not obese by their BMI or weight-for-height-for-age using World Health Organization standard definitions. The overall prevalence of obesity was 2.5% and 3.8% among hemoglobin genotype SS subjects and hemoglobin genotype AA controls, respectively. The age-specific prevalence for obesity was highest among the adolescent age category in hemoglobin genotype AA controls and the childhood age category in subjects with sickle cell anemia. All the obese subjects with sickle cell anemia were from upper socioeconomic strata, while two and one of the three subjects with hemoglobin genotype AA were from upper and middle socioeconomic strata, respectively. Obesity does exist among children with sickle cell anemia in Lagos, Nigeria. Public health programs aimed at prevention and control of obesity must include children with sickle cell anemia.     

Acute silent cerebral infarction in children with sickle cell anemia

Silent cerebral infarctions (SCI) occur in up to 35% of children with sickle cell anemia (HbSS) but are rarely recognized during the initial 10–14 days when diffusion weighted magnetic resonance imaging (MRI) can differentiate acute infarctions from remote events. We report acute SCI in seven children with HbSS who had areas of restricted diffusion on MRI without persistent focal neurologic deficits. Four had acute SCI identified following acute anemic events. Our observations suggest that SCI are detectible in the acute phase, present with subtle neurologic symptoms, result in permanent neurologic injury, and may be caused by acute anemic events. Pediatr Blood Cancer 2010;54:461–464. © 2009 Wiley‐Liss, Inc.