Natural history and evolution of anti-interferon-? autoantibody-associated immunodeficiency syndrome in Thailand and the United States

Background. The natural history of anti-interferon-? (IFN-?) autoantibody-associated immunodeficiency syndrome is not well understood. Methods. Data of 74 patients with anti-IFN-? autoantibodies at Srinagarind Hospital, Thailand, were collected annually (median follow-up duration, 7.5 years). Annual data for 19 patients and initial data for 4 patients with anti-IFN-? autoantibodies at the US National Institutes of Health were collected (median follow-up duration, 4.5 years). Anti-IFN-? autoantibody levels were measured in plasma samples. Results. Ninety-one percent of US patients were of Southeast Asian descent; there was a stronger female predominance (91%) in US than Thai (64%) patients. Mycobacterium abscessus (34%) and Mycobacterium avium complex (83%) were the most common nontuberculous mycobacteria in Thailand and the United States, respectively. Skin infections were more common in Thailand (P =.001), whereas bone (P <.0001), lung (P =.002), and central nervous system (P =.03) infections were more common in the United States. Twenty-four percent of Thai patients died, most from infections. None of the 19 US patients with follow-up data died. Anti-IFN-? autoantibody levels decreased over time in Thailand (P <.001) and the United States (P =.017), with either cyclophosphamide (P =.01) or rituximab therapy (P =.001). Conclusions. Patients with anti-IFN-? autoantibodies in Thailand and the United States had distinct demographic and clinical features. While titers generally decreased with time, anti-IFN-? autoantibody disease had a chronic clinical course with persistent infections and death. Close long-term surveillance for new infections is recommended.