Neutralizing Anti-Granulocyte-Macrophage Colony-Stimulating Factor Autoantibodies in Patients With Central Nervous System and Localized Cryptococcosis: Longitudinal Follow-up and Literature Review

Neutralizing anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies can predispose otherwise healthy individuals to exclusively pulmonary or localized cryptococcosis without central nervous system involvement. Despite the persistence of anti-GM-CSF autoantibodies, they generally had favorable outcomes without recurrence after completion of antifungal treatment. Background Neutralizing anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies (AAbs) have been increasingly recognized to predispose healthy individuals to disseminated cryptococcosis. However, studies have only considered patients with central nervous system (CNS) infection. No longitudinal study has captured the disease spectrum and clinical course. Methods We prospectively enrolled adults without human immunodeficiency virus infection who had disseminated or unusual cryptococcosis. We compared the demographics, clinical features, kinetics of serum cryptococcal antigen (CrAg) titers, anti-GM-CSF AAb concentrations, and treatment outcomes between patients with (case patients) and without (control patients) anti-GM-CSF AAbs. Additional reports from the literature were also reviewed. Results Twenty-three patients were enrolled, of whom 6 tested positive for anti-GM-CSF AAbs. All case patients with positive fungal cultures (5/5 [100%]) were infected with Cryptococcus gattii VGII. Among them, 3 had exclusively pulmonary involvement, and 1 had only musculoskeletal lesions. Patients with CNS cryptococcosis exhibited a higher serum concentration of anti-GM-CSF AAbs than those with extraneural cryptococcosis. Case patients had higher initial and peak levels of serum CrAg and longer duration of antigenemia compared with the control patients. All case patients who had completed antifungal therapy had favorable outcomes without recurrence. Conclusions Testing for anti-GM-CSF AAbs should be considered for not only previously healthy patients with disseminated cryptococcosis but also those with unexplained, localized cryptococcosis. Recurrence after completion of antifungal therapy was rare despite the persistence of anti-GM-CSF AAbs.

Automated summary

Neutralizing anti-GM-CSF autoantibodies can predispose healthy individuals to exclusive pulmonary or localized cryptococcosis without involvement of the central nervous system. Despite the persistence of these autoantibodies, favorable outcomes without recurrence can typically be achieved after antifungal treatment.