Serum cytokine levels in chronic progressive multiple sclerosis: interleukin-2 levels parallel tumor necrosis factor-alpha levels.

Serum levels of the cytokines interleukin-1 alpha (IL-I alpha), IL-1 beta, IL-2, IL-4, IL-6, tumor necrosis factor-alpha (TNF-alpha) and the soluble IL-2 receptor were measured in chronic progressive multiple sclerosis patients (CPMS) and normal, inflammatory, and noninflammatory disease controls. Serum IL-2 levels displayed the most consistent abnormalities in the group of tests for the CPMS group, and were the only cytokine levels to achieve significance in statistical group analyses. However, several patients with CPMS had normal serum IL-2 levels. An incidental finding was a statistical correlation between serum IL-2 and TNF-alpha levels among all groups tested. This finding was supported on analysis of serial serum samples from CPMS patients. These results suggest a linkage of IL-2 and TNF-alpha production, especially in pathological conditions.