Hemolysis due to high-dose intravenous gammaglobulin treatment for patients with idiopathic thrombocytopenic purpura.

Two adult patients with chronic idiopathic thrombocytopenic purpura (ITP) were treated with high-dose intact immunoglobulin (high-dose IgG). Haptoglobin levels in both cases declined significantly during high-dose IgG, following the increase in platelet counts to normal level. In one of them apparent hemolytic anemia was observed. The findings strongly support the hypothesis that the effect of high-dose intact IgG treatment on ITP patients is due to sequestration of IgG-coated autologous red blood cells by the reticuloendothelial system and the saturation of the macrophages by red blood cells.