Cytokine production and surface marker expression in acute and stable multiple sclerosis: altered IL-12 production and augmented signaling lymphocytic activation molecule (SLAM)-expressing lymphocytes in acute multiple sclerosis

Ag-stimulated IL-2 production and mitogen-stimulated type 1 and type 2 cytokine production by PBMC, as well as expression of Th1- and Th2-associated phenotypical markers, of B7-1, B7-2, and CD95 (Fas) on the surface of immune cells, and the serum concentration of soluble Apo-1/Fas were evaluated in multiple sclerosis (MS) patients with either acute (AMS) or stable (SMS) disease and in healthy controls (HC). Results showed that 1) Ag-stimulated IL-2 production is reduced in MS patients compared with that in HC; 2) mitogen-stimulated type 1 cytokine production is increased, and IL-10 production is reduced in MS patients compared with those in HC, and in AMS patients compared with those in SMS; 3) whereas production of the metabolically active p70 heterodimers is comparable in SMS, AMS, and HC, production of the p70 heterodimer and the p40 chains (total IL-12) is increased in SMS compared with that in AMS and HC; 4) CD4+, CD4+SLAM+, and CD4+CD7+ lymphocytes (preferentially type 1 cytokine-producing lymphocytes) are increased in MS compared with levels in HC; 5) B7-2- as well as Fas+- expressing monocytes are augmented in MS compared with those in HC, and serum soluble Apo-1/Fas is augmented in AMS compared with SMS and HC. These results confirm that a complex imbalance in both cytokine production and the Fas system is present in MS and indicate that different cytokine profiles may be observed in patients with acute or stable disease. The data also suggest that peculiar phenotypic populations are over-represented in MS patients, and for the first time show that SLAM expression is correlated with dysregulation of type 1 and type 2 cytokine production in human pathology.