[Effects of IL-2 and IL-6 on the immunoglobulin synthesis of lymphocytes from CVID patients].

Peripheral blood lymphocytes from five hypogammaglobulinemic patients suffering from common variable immunodeficiency (CVID) were stimulated with Staphylococcus aureus Cowan I (SAC) and pokeweed mitogen (PWM). The assays were substituted with interleukin-2 (IL-2) and interleukin-6 (IL-6) in different combinations. In three patients who were deficient for IgM in vivo a combination of SAC and IL-2 induced a normal IgM synthesis in vitro. In these patients a deficient IL-2 synthesis is probably the cause of CVID. In only one patient a "class switch" from IgM to IgG was detectable. Stimulation with PWM which is T-cell-dependent induced in one out of the five patients a normal IgM synthesis. Another CVID patient showed no defect in IgM or IgG synthesis in vitro. With these in vitro assays it seems possible to identify CVID patients who might profit from a therapy with human IL-2 in vivo.