PMN chemotactic inhibition associated with a cryoglobulin

A child with recurrent pyogenic infections, eczema, markedly elevated serum concentrations IgA, and totally absent PMN chemotactic acticity is described. The chemotactic defect was characterized as a humoral inhibitor present in serumand plasma, directed toward autologous as well as homologous PMN's. Immunochemical studies revealed the purified inhibitor to be a cryoglobulin composed of an IgM-IgA complex. Incubation of the cryoglobulin complex with PMN's resulted in a quantitative dose-response curve.