Pulse cyclophosphamide plus methylprednisolone induces myelin-antigen-specific IL-4-secreting T cells in multiple sclerosis patients.

Multiple sclerosis (MS) is a presumed cell-mediated Th1-type autoimmune disease. Thus therapies which decrease T cells secreting IFN-gamma production or increase IL-4 production would be expected to have an ameliorating effect on MS. We have previously reported increased anti-CD3-induced IL-4 secretion by T cells in progressive MS patients treated with cyclophosphamide plus methylprednisolone (CY/MP) which was associated with eosinophilia. To investigate whether the increased IL-4 secretion was myelin antigen specific, we generated 3990 short-term T cell lines to myelin basic protein (MBP), proteolipid protein (PLP), or tetanus toxoid (TT) from 31 progressive MS patients: 11 MS patients treated with CY/MP, 10 MS patients treated with MP alone, and 10 untreated MS patients. We found increased frequencies of both MBP- and PLP-specific IL-4-secreting T cell lines in CY/MP-treated patients compared to untreated MS patients. However, no change in the frequency of TT-specific IL-4-secreting T cells was observed. MP treatment alone did not increase the frequency of antigen-specific IL-4-secreting T cell lines. These results demonstrate immune deviation favoring Th2-type responses specific to autoantigens following pulse cyclophosphamide therapy in MS patients.