P489 Anti-granulocyte-macrophage colony-stimulating factor (Anti-GM-CSF) autoantibodies—the underrecognized cause of Cryptococcosis in non-HIV individuals in Thailand: Case series from a single tertiary care hospital

POSTER SESSION 1, SEPTEMBER 21, 2022, 12:30 PM - 1:30 PM: BACKGROUND: Cryptococcosis is an opportunistic fungal infection in immunocompromised patients. Granulocyte-macrophage colony-stimulating factor (GM-CSF) regulates the functions of phagocytes and alveolar macrophages, which are crucial in cryptococcal control. Anti-granulocyte-macrophage colony-stimulating factor (Anti-GM-CSF) autoantibodies have been found to be associated with cryptococcosis in non-HIV individuals but this syndrome has never been described in Thai population. METHODS: We report here the case series of patients hospitalized in a tertiary care hospital in Northern Thailand. RESULTS: Three apparently immunocompetent patients, 34, 38, and 45 years old, were presented with neurological manifestations. Brain computed tomography scans and lumbar punctures were performed and the results showed evidence of cryptococcal meningoencephalitis. Two of the patients also had pulmonary cryptococcosis. We performed Anti-GM-CSF autoantibody ELISA assays in the patient's sera and all of three serum samples revealed a high titer of anti-GM-CSF autoantibodies. The patients were treated with amphotericin B deoxycholate with or without flucytosine for induction antifungal therapy, followed by fluconazole consolidation treatment. All patients were cured and had favorable outcomes. CONCLUSIONS: Anti-GM-CSF autoantibodies syndrome is underrecognized in Thai patients and is a new entity of immunodeficiency associated with cryptococcal meningoencephalitis and disseminated cryptococcosis in Thai patients.