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Background. Silent infarcts have been reported in 17% of young patients with sickle cell disease and are associated with impaired performance on standardized psychometric tests. Risk factors for the development of these lesions have not been identified. Methods. Investigators in the Cooperative Study of Sickle Cell Disease performed a brain magnetic resonance imaging scan on sickle cell anemia patients age 5.9 years and older who had been followed according to the protocols of the Cooperative Study since birth. Individuals with a known history of cerebrovascular accident were excluded from this analysis. Patients with and without silent infarctions were compared with regard to clinical and laboratory parameters. Results. The study sample included 42 patients (18.3%) with silent infarcts. Patients who had silent infarcts were significantly more likely to have a clinical history of seizure and a lower painful event rate. Lower hemoglobin level, increased leukocyte count, elevated pocked red blood cell count, and SEN βS globin gene haplotype were associated also with the presence of silent infarcts. There was no relationship between silent infarcts and platelet count, fetal hemoglobin level, reticulocyte percentage, serum aspartate aminotransferase level, total bilirubin concentration, blood pressure, growth parameters, or presence of α-thalassemia. A multivariate model for silent infarction identified the following as risk factors: low pain event rate, history of seizure, leukocyte count ≥11.8 × 109/L, and the SEN βS globin gene haplotype. Conclusions. Patients with risk factors for silent infarcts should be evaluated for cerebrovascular disease. If evidence of infarction is found, consideration must be given to therapeutic intervention. At present, the appropriate treatment has not been determined.

The development of platelet alloimmunization is a common and potentially severe consequence in patients who receive frequent platelet transfusions. The use of single-donor pheresis units or human lymphocyte antigen (HLA)-matched platelets to prevent or delay the onset of alloimmunization is often unsuccessful. Once sensitization occurs and refractoriness to platelet transfusions develops, patients are at risk of severe bleeding which may be difficult to manage. There has been no reliably effective therapy for such patients once alloimmunization occurs. High-dose intravenous (IV) immunoglobulin therapy has been used to treat patients with autoimmune thrombocytopenia,1-4 autoimmune neutropenia,5,6 and posttransfusion purpura.7 Because of its success in these disorders, IV immunoglobulin was given to two patients with hemorrhagic symptoms who were refractory to platelet transfusions because of alloimmunization.

Controversy still exists as to the best laboratory method to use to screen newborns for sickle cell disease and other hemoglobinopathies. The proposed methods include hemoglobin electrophoresis, column chromatography, isoelectric focusing, and high performance liquid chromatography. There is also debate concerning the preferred method of sample collection. The proposed methods of sample collection include cord blood or blood obtained from the infant collected in a tube with anticoagulant or on filter paper. We compared hemoglobin electrophoresis patterns from infant blood samples collected in heparinized capillary tubes and on filter paper. This comparison was performed because hemoglobin electrophoresis of dried blood samples collected on filter paper has been advocated as a practical, reliable, and inexpensive method for mass screening programs, although the limitations of this technique have not been explored fully. We also summarize data from the North Carolina Newborn Hemoglobinopathy Screening Program, which relates to the advantages and limitations of hemoglobin electrophoresis from filter paper blood specimens. MATERIALS AND METHODS Specimens Four sets of specimens were used for this study: (1) specimens collected at Duke University Medical Center to compare hemoglobin electrophoresis patterns of hemolysates from filter paper and heparinized capillary tubes, (2) specimens collected by the North Carolina program for hemoglobinopathy screening, (3) specimens routinely collected at Duke University in heparinized capillary tubes for newborn hemoglobinopathy screening, and (4) samples for retesting to examine the error rate of the state program and to confirm screening results compatible with a hemoglobinopathy. Samples for Direct Comparison Between Filter Paper and Heparinized Specimens

A study of the natural history of sickle hemoglobinopathies was begun in March 1979. By August 1987, a total of 2824 patients 10 years of age. There was limited success in identifying risk factors for death. Comparison of this study's overall mortality of 2.6% (0.5 deaths per 100 person-years) with previous reports indicates improvement of survival in US patients