B cell dysfunction in haemophilia in the absence and presence of HIV-1 infection

56 haemophiliacs selected on the basis of HIV-1 antibody status, liver disease grade and mean annual dose of clotting factor concentrate used were studied. Spontaneous and stimulated IgG and IgM production in vitro were measured. HIV-1 infection was associated with increased spontaneous immunoglobulin production and an impaired response to pokeweed mitogen and Staph Aureus protein A. Implying a shift in the proportions of partially and fully activated B cells. In the absence of HIV-1 infection there was a shift to a greater proportion of partially activated B cells in patients with severe liver disease. The remainder had in vitro immunoglobulin production comparable to controls. B cell abnormalities occur early in the course of HIV-1 infection. Liver disease and not clotting factor concentrate treatment cause B cell abnormalities in the absence of HIV-1 infection in haemophilia.