Immune complexes in hemophilia.

Circulating immune complexes (ICs), assayed by the L1210 enzyme-linked immunoassay, were detected in 48% of patients with hemophilia. A, 50% of patients with von Willebrand's disease, and in none of our patients with hemophilia B. Eighty-five % of the hemophilia A and B patients had mild to moderate disease with only one patient demonstrating a circulating inhibitor. No correlation was found between IC levels and hepatitis B infection, SGOT, disease severity, total quantity of factor VIII or IX infused, time interval from list infusion, or rheumatoid factor positivity. Although the nature of the ICs is not known, the similarity of IC levels between hemophilia A and von Willebrand's disease is discussed with regard to antibodies generated to non-procoagulant portions of the factor VIII molecule.