Effect of a single bolus infusion (0.4 g/kg) of IVIg on IgG, IgA, and IgM production in purified B-lymphocyte cultures from 8 patients with HIV infection. B lymphocytes were prepared from blood samples taken at the indicated time points before and after IVIg infusion and cultured without stimulation (left panels) or stimulated with anti-CD40 monoclonal antibody (right panels). Supernatants were harvested after 7 days and assayed for Igs by ELISA. Data are given as medians and 25th and 75th percentiles. *P < .05 versus levels before infusion (0 hours).