Reduced TH-1 cytokine release in an adult patient with chronic relapsing Mycobacterium malmoense infection

An unusual course of infection with Mycobacterium malmoense is described in a patient receiving chronic but mild immunosuppressive therapy for rheumatoid arthritis. Symptoms mimicking Crohn's disease deteriorated under intensified immunosuppression and surgery. Judging from the patient's course under treatment specific for M. malmoense, the gastrointestinal symptoms were rather manifestations of a chronic relapsing mycobacterial infection. Detailed immunological investigation of the patient revealed a severely impaired TH-1 cytokine response as the immunological background for this uncommon course.