Lymphocyte populations and cellular immune reactions in vitro in patients with multiple sclerosis

Abstract Lymphocytes isolated from the peripheral blood of a group of nine multiple sclerosis (MS) patients with recently developed disease (median disease duration, 1 year), from a group of 14 patients with MS of long standing (median disease duration, 26 years), and from age- and sex-matched healthy blood donors were studied. The absolute and relative numbers of the major lymphocyte populations in peripheral blood of MS patients do not indicate that the disease is associated with an alteration in any of these. In patients with recently developed disease, lymphocyte transformation induced by a panel of mitogens was similar to, or even higher than, that of control donors, while data from similar tests in the other patient group demonstrated a moderately impaired lymphocyte function. Phytohemagglutinin (PHA)-induced lymphocyte-mediated cytotoxicity was subnormal in four patients, belonging to both groups, while cytotoxicity induced by antibody-coated target cells (“K-cell”-induced cytotoxicity) was normal.