SHM Converge Scientific Abstract ePoster Gallery-Noteworthy Acquired Immunodeficiency in a Gracious Adult

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This document describes a case of a 46-year-old Filipina woman with systemic lupus erythematosus on prednisone, mycophenolate, and hydroxychloroquine who developed a 6-month history of dry cough, dyspnea, weight loss, and new hypoxemia. Imaging showed a bulky mediastinal mass encasing the airways, pulmonary consolidation, and thoracic adenopathy. Initial concern included malignancy or opportunistic infection. HIV testing was negative. Sputum studies were acid-fast bacilli positive, but tuberculosis testing was negative. Bronchial biopsy showed severe acute inflammation with granulomatous inflammation and extensive acid-fast organisms, and cultures from sputum, BAL, and blood grew macrolide-sensitive Mycobacterium avium complex (MAC).<br /><br />Despite appropriate antimycobacterial therapy, the patient worsened, with spread of infection to the pleural space and persistent positive blood cultures. Because of the severity and refractoriness of the infection, an underlying immune defect was suspected. Further workup revealed neutralizing anti-interferon-gamma autoantibodies (NAIGA), causing acquired immunodeficiency. Her HLA testing showed risk-associated class II alleles linked to this syndrome in East Asian populations.<br /><br />The key teaching points are:<br />- Severe or disseminated nontuberculous mycobacterial infection should prompt evaluation for immune deficiency.<br />- NAIGA are an acquired immunodeficiency seen especially in adults of East Asian descent.<br />- These antibodies block interferon-gamma signaling through STAT1, impairing granuloma formation and protective cytokine responses.<br />- Antimicrobial therapy alone may be insufficient; immunomodulatory treatment may be needed to restore immune function and control infection.<br /><br />The case highlights the importance of recognizing NAIGA in patients with severe NTM disease, especially those with relevant ancestry or autoimmune disease.

Asset Subtitle

Maura Thornton

Meta Tag

Author List Jennifer J. McEntee, Maura Thornton

Category Clinical Vignettes

Concept Nontuberculous Mycobacterial Infection

Concept Anti-Interferon-Gamma Autoantibodies

Concept Mycobacterium avium complex

Concept Immunodeficiency

Concept Interferon-Gamma Signaling

Distinguished Non-Finalist

Presenter Organization UNC Hospitals Internal Medicine Residency

Presenting Author Maura Thornton

Track Adult

Keywords

systemic lupus erythematosus

Mycobacterium avium complex

anti-interferon-gamma autoantibodies

nontuberculous mycobacterial infection

acquired immunodeficiency

mediastinal mass

granulomatous inflammation

hypoxemia

disseminated infection

immunomodulatory treatment

Nontuberculous Mycobacterial Infection

Anti-Interferon-Gamma Autoantibodies

Mycobacterium avium complex

Immunodeficiency

Interferon-Gamma Signaling