title: Low-titer cold-hemagglutinin disease. Mechanism of hemolysis and response to corticosteroids.
abstract: We studied two patients with a low-titer cold-hemagglutinin disease syndrome to investigate the mechanism of hemolysis and the therapeutic response to corticosteroids. The antierythrocyte antibody was of the IgM class, had a high thermal amplitude and had enough activity of 37 degrees C to account for the hemolysis. The capacity of peripheral blood monocytes to increase the osmotic fragility of C3-coated erythrocytes suggests that macrophage interaction with C3-coated erythrocytes explains the observed in vivo spherocytosis. Both patients responded to high-dose corticosteroids. The data suggest that the steroid effect is probably due to alteration of macrophage complement-receptor function. These studies demonstrate the importance of antibody activity at body temperature in producing hemolysis, particularly in this variant of cold-hemagglutinin disease. The response to steroids suggests the efficacy of corticosteroid therapy in alleviating hemolysis due to macrophage recognition of erythrocytes coated with IgM and C3.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000373:Agglutinins / Q000032:analysis*; D000744:Anemia, Hemolytic, Autoimmune / Q000276:immunology; D001323:Autoantibodies; D003080:Cold Temperature; D003176:Complement C3 / Q000032:analysis; D003186:Complement C9 / Q000032:analysis; D005260:Female; D006386:Hemagglutination Tests; D006461:Hemolysis; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000188:drug therapy / Q000276:immunology*; D013102:Spherocytes / Q000276:immunology; D013696:Temperature
chemical_list: D000305:Adrenal Cortex Hormones; D000373:Agglutinins; D001323:Autoantibodies; D003176:Complement C3; D003186:Complement C9; D007075:Immunoglobulin M