Long term azathioprine fails to prevent onset of multiple sclerosis: Report of two cases

Azathioprine is on immunosuppressive drug widely used in the treatment of chronic inflammatory diseases, including Multiple Sclerosis (MS). We report two patients who developed the first manifestations of clinically definite multiple sclerosis while on long term (3.5 and 10 years respectively) treatment with azothioprine for Crohn's disease. Both patients developed the first MS symptoms during a quiescent phase of their inflammatory bowel disease. These cases show that long term azathioprine, while possibly maintaining inflammatory bowel disease under control, could not prevent the onset of MS.