Long-term immunological changes in azathioprine-treated MS patients.

The long-term immunological effects of azathioprine treatment have been investigated in 8 multiple sclerosis patients with different course of disease, chronic progressive (CP) or relapsing progressive (RP). We studied fluctuations in peripheral blood mononuclear cell subsets, IgG, IgM and soluble vascular cell adhesion molecule-1 (sVCAM-1), before and after 2 (T24) and 3 (T36) years of therapy. We observed a significant decrease in CD8+ cells over time and a trend to lower percentage of CD3-CD56+ cells at T24 and T36. CD4+CD45RA+ cells in MS patients were lower than in healthy controls before therapy and reached values similar to those of healthy controls at T24 and T36. The remaining immunological parameters did not show any significant fluctuations.