Impaired apoptosis in mitogen-stimulated lymphocytes of patients with multiple sclerosis

WE investigated the sensitivity to cell death of peripheral blood mononucle ar cells (PBMCs) from patients with multiple sclerosis (MS). PBMCs from MS patients, following PHA stimulation, were less sensitive to cell death than those from healthy donors (mean +/- s.e.m., 22.5 +/- 1.9 in MS patients ws 36.5 +/- 2.8 in healthy controls; p = 0.0003). However, when Fas-agonist a ntibody was added, the increase in respect to apoptosis induced by mitogen alone was even higher in MS patients than in controls. In addition, PHA-act ivated PBMCs from MS patients showed higher surface expression of Fas than controls, while Bcl-2 expression was decreased. This finding raised the que stion of whether an impaired generation of apoptotic signals may be contrib uting to the immune component of MS. (C) 1999 Lippincott Williams & Wilkins .