TNF-α, IL-12p35, IL-12p40, IL-4, IL-10, TGF-β1, CCR3, CXCR3, CCR5, Fas and FasL mRNA levels in PBMC of 25 multiple sclerosis (MS) patients were quantified at baseline by real-time PCR according to a post-hoc study design. The baseline values of the different markers were analysed with respect to their correlation with the increase in disability over a period of 10 years. High levels of Fas mRNA were associated with a favourable disease course in relapsing-remitting (RR) MS (R2 = 0.74, P = 0.0001, n = 13), as measured by the Expanded Disability Status Scale (EDSS); high levels of FasL mRNA were associated with relatively mild disease progression (R2 = 0.86, P = 0.0001, n = 12) in secondary progressive (SP) MS. These findings suggest that Fas-mediated apoptosis plays a major role in the mechanism underlying long-term disease progression in MS. © 2006 SAGE Publications. Chemicals / CAS: osteopontin, 106441-73-0; Antibodies, Monoclonal; Antigens, CD95; Biological Markers; Chemokines; Cytokines; Fas Ligand Protein; RNA, Messenger