Immune complexes in the pathogenesis of hypergammaglobulinemic purpura.

Direct immunofluorescence (DIF) was performed and circulating immune complex (CIC) levels evaluated in three patients with hypergammaglobulinemia purpura (HGP) of Waldenström. The Raji cell immunoradiometric assay was used to detect complexes of both IgG and IgM type. IgM and C3 were detected in blood vessel walls of all three patients. Elevated levels of IgG complexes were detected in two patients, and elevated levels of IgM complexes were detected in all three patients. Clinical improvement after plasmapheresis was noted in one patient. A cause-and-effect relationship between CIC and the inflammation of the superficial dermal blood vessels is postulated.