THE IMMUNE PROFILE OF MULTIPLE-SCLEROSIS - T-LYMPHOCYTE EFFECTS PREDOMINATE OVER ALL OTHER FACTORS IN CYCLOPHOSPHAMIDE-TREATED PATIENTS

It is widely believed that multiple sclerosis is a T-cell mediated aut oimmune disease associated with abnormalities in immunoregulation. Thi s large, prospective study evaluated the lymphocyte immunophenotypic p rofile of 246 MS patients, divided clinically into a remitting/relapsi ng group (n = 176) and a progressive group (n = 70), and compared thei r results to those of 117 healthy controls. All patients were found to have significantly elevated percentage and absolute numbers of IL2R()CD3(+) cells as well as depressed percentages of CD45RA(+)CD4(+) cell s. However, when the factor of treatment with cyclophosphamide (CY) ve rsus no treatment or treatment with other agents was used to group pat ients, dramatic declines in both percentages and absolute numbers of C D45RA(+) CD4(+) cells were discovered. These declines were associated specifically with CY and could be explained by this factor independent of the clinical state of the patient. The effects were seen in patien ts undergoing current treatment or in those exposed to CY in the near or remote past. These findings highlight the confounding effect of spe cific treatments on the immune profile of MS patient groups and sugges t that there may be important implications for cellular function and c linical outcome in these and other patient groups.