[Adult-onset immunodeficiency induced by anti-interferon-γ autoantibodies: report of 13 cases]

Objective: To investigate the clinical characteristics of a group of patients with adult-onset immunodeficiency (AOID) induced by anti-interferon-γ autoantibodies (AIGA). Methods: Thirteen cases of AOID in a northern China medical center (Peking Union Medical College Hospital) from October 2020 to April 2022 were included. Data comprising clinical manifestations, laboratory results, infection sites and pathogens were collected. Results: Among the 13 patients, 5 were male. The median age of disease onset was 47 (14 to 71) years. The median time from symptom onset to diagnosis was 4 years (1 to 8 years). Four patients were from northern China, and 9 from southern China. Common symptoms included lymphadenopathy (13/13), fever (12/13), respiratory tract symptoms (12/13), and weight loss (11/13). Laboratory tests showed increased levels of white blood cell count (9/13), neutrophil count and proportion (9/13), erythrocyte sedimentation rate (ESR) (12/13), and C reactive protein (CRP) (11/13). The median plasma titers of AIGA upon diagnosis were 5681(3194, 13246). Sites of infection included lungs (12/13), lymph nodes (9/13), bones and joints (9/13), skin and soft tissue (7/13), blood flow and bone marrow (4/13), and glands (3/13). Most patients had nontuberculous mycobacteria (NTM) (12/13) infection. Seven patients had more than one pathogen. Conclusions: AOID also affects patients visiting northern China hospitals. AIGA screening is recommended among patients with disseminated NTM infections or recurrent infections.