[Reconstitution of immunoglobulin production in patients with variable immunodeficiency syndrome (CVI) by the CD40 system and IL-10].

Common variable immunodeficiency (CVI) is widely believed to involve a primary B cell defect, however, there is increasing evidence of T cell dysfunction in these patients. To test the hypothesis that B cells of patients with CVI are not defective, we investigated whether immunoglobulin production can be induced by activation through the CD40 system. Our results show that 6 of 7 children with CVI produced IgG when B cells were activated through CD40 plus IL-10. In most patients, IgM and IgA production were also induced. However, we could demonstrate that failure of immunoglobulin production was not due to a defective CD40 ligand expression on T cells. Taken together, our data show that B cells of patients with CVI are functionally normal when activated through CD40 plus IL-10. IL-10 seems to be more effective than IL-2 in restoration of immunoglobulin production in such patients.