Serial studies of serum interleukin-2 in chronic progressive multiple sclerosis patients: occurrence of 'bursts' and effect of cyclosporine

Serum levels of immunoreactive interleukin-2 (IL-2) were determined at monthly intervals from a group of placebo- and drug-treated chronic progressive multiple sclerosis patients before and during a cyclosporine A therapeutic trial. Significantly elevated levels of the lymphokine in active patients confirmed earlier studies. The magnitude of the initial levels varied inversely with the duration of disease and predicted subsequent worsening in chronic progressive patients. In addition, the occurrence of periodic bursts of serum IL-2 was noted. Although in some patients there appeared to be a sudden drop in serum IL-2 levels with the onset of cyclosporine A medication, no effect of this drug was noted on group analysis.