Leukocytes from multiple sclerosis patients respond to alpha- and gamma-interferons.

Blood mononuclear leukocytes from multiple sclerosis (MS) patients were evaluated for reactivity to alpha- or gamma-interferon (IFN), using a response whereby IFN-treated (primed) cells synthesize higher levels of IFN than untreated cells. Leukocytes were treated in vitro with natural alpha-IFN, recombinant alpha-IFN, recombinant gamma-IFN, or no IFN, then exposed to measles virus to induce IFN synthesis. With no IFN treatment, IFN production by cells from the MS patients was significantly less than normal (P less than or equal to 0.025). However, with IFN treatment, cells from MS patients were primed as well as cells from normal controls: IFN synthesis for the MS patients' cells was increased 10-11-fold with either alpha-IFN preparation and 3.6-fold with gamma-IFN. These findings verify the presence of leukocyte reactivity to alpha-IFN and provide the first demonstration of responsiveness to gamma-IFN in MS.