Good's Syndrome Complicated with COVID-19 and Recurrent Pulmonary Infections: A Case Report.

Good's syndrome (GS), a rare immunodeficiency disorder characterized by thymoma and hypogammaglobulinemia, presents diagnostic and therapeutic challenges due to recurrent infections. We report a 53-year-old male farmer with GS complicated by recurrent pulmonary infections and COVID-19. Initial management focused on antiviral/anti-infective therapy and corticosteroids, but persistent hypogammaglobulinemia, B-cell depletion, and thymoma history were overlooked. Diagnosis was confirmed upon integrating the thymoma history, immunological profiling, and bronchial alveolar lavage-next generation sequencing, revealing Pneumocystis jirovecii and Herpes Simplex Virus-1 coinfections. Treatment with intravenous immunoglobulin loading dose (2 g/kg), pathogen-targeted therapy (voriconazole, cotrimoxazole), and tapered corticosteroids achieved clinical remission, with immunoglobulin G (IgG) elevating to 6.35 g/L. This case underscores the necessity of a "four-dimensional early warning system" integrating thymoma history, immune, imaging, and pathogen for timely GS diagnosis. Multidisciplinary collaboration and personalized regimens combining immunoglobulin replacement, precision anti-infectives, and immunomodulation are pivotal for optimizing outcomes in GS patients with complex infections.