Interferon-gamma-secreting cells in multiple sclerosis patients treated with interferon beta-1b.

Fifteen percent of multiple sclerosis patients about to be treated with interferon beta-1b exhibited elevated numbers of circulating interferon-gamma-secreting cells, defined as a value that exceeded the mean value for healthy controls by more than two standard deviations. Sixty percent of patients receiving the drug exhibited elevated interferon-gamma-secreting cell numbers during their first 2 months of treatment. Values normalized after 3 months. Prednisone treatment during the first month on the drug prevented the interferon-gamma-secreting cell surge.