Serum immunoglobulin levels in patients having sickle cell syndromes.

Serum immunoglobulin concentrations were measured for 44 patients who had sickle cell syndromes and for 19 normal black individuals. Most patients who had sickle cell syndrome had significantly elevated IgA levels. In addition, patients who had sickle cell anemia had elevated IgG levels, and patients who had sickle-beta-Thalassemia or other sickle combinations (SC, SD, SO) had significantly elevated IgM levels. None of these patients had a monoclonal gammopathy. The elevated immunoglobulin levels could be the result of chronic reticuloendothelial stimulation by chronic extravascular hemolysis or by potentiation by the inflammation secondary to cholecystitis and cholelithiasis. The reason patients with sickle cell anemia do not have increased IgM levels could be due to their functional asplenia.