Immune Interference: A Man with Rash and Lymphadenopathy

A prior lymph-node biopsy had shown atypical T-cells without a definitive diagnosis. Current examination showed a pustular rash involving the trunk and palms (Figure 1). Subsequently, blood and lymph-node cultures grew Mycobacterium abscessus. The patient did not have known immunosuppression, but discrepancy between the two controls of different interferon-γ release assays (IGRAs) suggested an intrinsic defect in the interferon-γ pathway. Testing showed neutralizing antibodies against interferon-γ, and the patient was diagnosed with anti–interferon-γ autoantibody syndrome.