Multiple sclerosis associated with interferon-alpha therapy for chronic myelogenous leukemia

We report a chronic myelogenous leukemia (CML) patient in chronic phase (CP) who developed multiple sclerosis (MS) in association with interferon-alpha (IFN-α) administration. In our patient, recombinant IFN-α2b therapy induced hematologically complete and cytogenetically major partial response for CML first, and sequential central nervous system dysfunction evolved, which subsided shortly after the cessation of its administration. Restarting IFN-α therapy by changing to a natural type of IFN-α resulted in rapid exacerbation of MS. The patient's neurological symptoms progressed gradually, but partial hematologic response persisted without any IFN-α derivatives or anti-cancer agents until a matched unrelated donor transplant procedure was performed. Myeloablative therapy led to lasting stable state of MS and finally to complete cytogenetic remission of CML. This patient's presenting clinical course and laboratory data suggest that both exertion of anti-leukemic activity and autoimmune process of MS might be mediated by mutual mechanisms, such as enhancement of specific cellular immunity induced by IFN-α.