Lymphocyte phenotype and function in chronically transfused children with sickle cell disease.

Immunologic studies were performed on mononuclear cells from ten chronically transfused children with sickle cell disease, and the results were compared with those from five other groups: 21 sickle cell patients who were not receiving regular transfusions, 6 chronically transfused children with other forms of refractory anemia, 10 previously splenectomized children, 5 boys with hemophilia A, and 27 normal adult controls. The helper:suppressor T cell ratios (T4:T8) in all groups except hemophiliacs were normal, were unrelated to the number of units transfused, and were not suggestive of findings reported for patients with the acquired immune deficiency syndrome (AIDS) or groups at risk for the syndrome. Percentages of T3, T4, and T8 cells were low in sickle cell and splenectomized patients, but not in chronically transfused patients with other anemias. Serum IgG was frequently elevated, and IgG synthesis in vitro was increased relative to IgM synthesis in sickle cell patients. Coculture experiments indicated that such findings may stem from a selective increase in IgG synthesis by B cells. Thus, transfused sickle cell patients have a particular pattern of immunologic abnormalities that is distinct from that seen in AIDS.