INCREASED IL-6 GENE-EXPRESSION AND PRODUCTION IN PATIENTS WITH COMMONVARIABLE IMMUNODEFICIENCY

We have studied IL-6 gene expression and production by in vitro stimul ated peripheral blood mononuclear cells (PBMC) isolated from common va riable immunodeficiency (CVI) patients. A strong hybridization signal for the IL-6 probe was observed in mRNA extracted from phytohaemagglut inin (PHA)- and PHA/phorbol myristate acetate (PMA)-stimulated PBMC fr om most of 12 CVI patients analysed. IL-6 production by PHA-stimulated PBMC from 28 CVI patients was evaluated in ELISA and found to be sign ificantly (P < 0.0001) higher than in normal controls. IL-6 production , however, did not correlate with the lymphocyte populations examined, nor with the absolute number of monocytes. We have also showed that I L-6 was able to increase IgM secretion by several Epstein-Barr virus ( EBV)-transformed cell lines derived from both normal donors and CVI pa tients, but it failed to modify substantially the amounts of IgM and I gG produced in vitro by PBMC derived from CVI patients and activated w ith pokeweed mitogen (PWM) or anti-IgM. Our data indicate that IL-6 ge ne expression and production is increased in CVI, but CVI cells do not respond to IL-6 with increased production of immunoglobulin.