IL-10 PRODUCTION AND CD40L EXPRESSION IN PATIENTS WITH COMMON VARIABLE IMMUNODEFICIENCY

The authors studied CD40 ligand (CD40L) expression and interleukin-10 (IL-10) production in 16 patients with common variable immunodeficienc y (CVI). Mean CD40L expression, determined by using cytofluorimetry, a nd measured as the mean fluorescence intensity following stimulation o f peripheral blood mononuclear cells (PBMC) with phorbol myristate ace tate (PMA) and calcium ionophore in 12 patients, was comparable to tha t of controls. However, three CVI patients showed fluorescence intensi ty in stimulated cells below 2 standard deviations of normal donors' m ean and two other patients had only a slight increase of stimulated ve rsus unstimulated cells (< 10 channels). IL-10 production after stimul ation of PBMC with both anti-CD3 or anti-CD3 plus PMA gave similar res ults in CVI patients and normal controls. In vitro stimulation of PBMC with anti-CD40 and various combinations of cytokines (IL-2, IL-4 and IL-10) induced IgG production above 100 ng/ml in one CVI patient out o f 13 tested. The data suggest that alterations of IL-10 production are unlikely to play a major role in the pathogenesis of impaired IgG pro duction in most CVI patients. CD40L appears to be normally expressed i n two thirds of CVI patients, but it may be functionally defective.