INTERFERON GAMMA-SECRETING AND INTERLEUKIN-4-SECRETING CELLS IN MULTIPLE-SCLEROSIS

Interleukin 4 (IL-4)- and interferon gamma (IFNgamma)-secreting periph eral blood cells were enumerated by immunospot assay in 13 multiple sc lerosis (MS) patients during exacerbations, in 24 patients with progre ssive multiple sclerosis (CPMS), and in 20 controls. Cells that sponta neously secreted IFNgamma were significantly higher in MS patients exp eriencing an attack (P < 0.001) than in controls or in CPMS (P < 0.04) . IL-4-secreting cell numbers were elevated significantly and to a com parable extent in both MS groups compared to controls. Our finding of increased numbers of IFNgamma-secreting cells is in keeping with prior work showing increased IFNgamma levels in the circulation prior to an d during MS attacks and increased release of IFNgamma to the supernata nt in bulk cultured blood cells from MS patients. What role an increas e in IL-4-secreting cells might play in MS is unclear, but it could re late to immune system regulation. Following in vitro exposure to MBP, IFNgamma-secreting cell number rose above levels observed in the absen ce of stimulation in controls and in both MS groups with the rise in a cutely exacerbating MS patients being significantly greater than in co ntrols. Our results provide further evidence for reactivity to MBP in MS, the significance of which in terms of pathogenesis remains clouded .