Type 1 immune response in progressive multiple sclerosis.

The aim of the study was to evaluate the type-1 immune response by analyzing T-bet expression in circulating T and B cells in Primary Progressive (PP) and Secondary Progressive (SP) Multiple Sclerosis (MS) patients. We found higher percentages of circulating CD4+T-bet+ and CD8+T-bet+ T cells in SPMS and PPMS than in remitting-relapsing MS patients and controls. Moreover, in SPMS, we observed a positive correlation between the percentages of circulating CD4+T-bet+ or CD8+T-bet+ T cells and disease severity. The increased percentages of Th1 and Tc1 cells suggest that MS progressive forms, unlike RRMS, are characterized by a permanent peripheral type-1 immune activation.