Abstract
BACKGROUND: Anti-interferon (IFN)-gamma (γ) autoantibody positivity (AIGA) is a rare cause of adult-onset immunodeficiency, leading to severe disseminated opportunistic infections with varying outcomes. Due to its rarity, the diagnosis of AIGA is often missed or delayed. METHODS: We used the hospital information system of the First Affiliated Hospital of Wenzhou Medical University to retrospectively analyze the data of patients with AIGA between January 2018 and March 2024. Clinical, laboratory, and outcome data were collected and analyzed. RESULTS: Six patients with AIGA were included in this study. A retrospective review of the clinical characteristics and laboratory results showed that all patients had recurrent opportunistic infections, and five patients had hypergammaglobulinemia before receiving the diagnosis of AIGA. All six patients presented with pneumonia and recurrent cough; two patients presented with recurrent skin abscesses, two presented with recurrent penile ulcers, and two presented with severe bone destruction. Of these, five patients were infected with Talaromyces marneffei (T. marneffei). After being diagnosed with AIGA, all six patients received routine anti-infection therapy. As the disease progressed, all patients presented with recurrent infections. Notably, five patients exhibited elevated serum immunoglobulin G (IgG) (median 25.06 g/L; interquartile range, 17.73-38.22) during a previous admission. One succumbed to respiratory failure at follow-up, while five survived. CONCLUSION: The diagnosis of AIGA is often delayed and should be considered as a differential diagnosis in patients with recurrent opportunistic infections and hypergammaglobulinemia.