Journal ofNeuroimmunology, 14 (1987) 183-187 183 Elsevier JNI 00461 Molecular analysis of the CD8 gene in multiple sclerosis Anthony T. Reder 1, Jack P. Antel 1, Sunanda Singh 2, Carmelina Stoklosa 2 and Vikas Sukhatme 2 Departments of I Neurology and 2 Medicine, University of Chicago and Howard Hughes Medical Institute and the Brain Research Institute, 5841 Maryland Avenue, Chicago, IL 60637, U.S.A. (Received 30 June 1986) (Revised, received 25 August 1986) (Accepted 26 August 1986) Key words." CD8 gene; Leu 2; OKTS; Multiple sclerosis; Suppressor cells; Concanavalin A-induced suppressor cells Summary Analysis of DNA fragments of the CD8 gene following digestion with three restriction enzymes showed no differences between patients with chronic progressive multiple sclerosis (MS), familial MS and controls. These abnormalities suggest that any abnormalities in the expression of CD8 protein in MS are not likely to be due to a gross deletion or rearrangement of the CD8 gene. Introduction In multiple sclerosis (MS) repeated episodes of central nervous system (CNS) demyelination are associated with a series of abnorrnalities of the immune system, including immune regulation. During active disease, the number of suppressor/ cytotoxic blood lymphocytes defined by the presence of the CD8 differentiation antigen has been reported to be reduced in absolute or relative numbers by several groups (Reder and Arnason 1985). In their initial studies, in which a marked Address for correspondence: Dr. Anthony Reder, Department of Neurology, 5841 Maryland Avenue, Box 425, Chicago, IL 60637, U.S.A. 0165-5728/87/$03.50 © 1987 Elsevier Science Publishers B.V. (Biomedical Division)