Coinfection by Talaromyces marneffei and Mycobacterium abscessus in a human immunodeficiency virus-negative patient with anti-interferon-γ autoantibody: a case report

Abstract

Patients with anti-interferon (IFN)-γ autoantibodies have weakened immune defenses against intracellular pathogens. Because of its low incidence and non-specific symptoms, diagnosis of anti-IFN-γ autoantibody syndrome is difficult to establish during the early stages of infection. Here, we report a patient with high titers of serum anti-IFN-γ autoantibodies suffering from opportunistic infections. The patient presented with intermittent fever for 2 weeks. During his first hospitalization, he was diagnosed with Talaromyces marneffei pulmonary infection and successfully treated with antifungal therapy. However, multiple cervical lymph nodes subsequently became progressively enlarged. Mycobacterium abscessus infection was confirmed by positive cervical lymph node tissue cultures. High-titer serum anti-IFN-γ antibodies were also detected. Following anti-M. abscessus therapy, both his symptoms and lymph node lymphadenitis gradually improved. Anti-IFN-γ autoantibody syndrome should be considered in adult patients with severe opportunistic coinfections in the absence of other known risk factors.

Keywords: Case report; Mycobacterium abscessus; Talaromyces marneffei; adult onset immunodeficiency; anti-interferon-γ autoantibodies; non-tuberculous mycobacteria.

Figure 1.

Chest computed (CT) images at different times. (A–D) Chest CT on 3 December 2019 showed patchy infiltration in the right upper lobe (black arrows) and mediastinal lymph node enlargement (white arrows). (E–H) Chest CT on 17 December 2019 showed exacerbated infiltration and alveolar consolidation in the left upper lobe, new patchy infiltration in the right lower lobe and left lingular bronchus (black arrows), and progressively enlarged mediastinal lymph nodes (white arrows). (I–L) Chest CT on 26 March 2020 showed marked improvement of pulmonary lesions after treatment.

Figure 2.

Cultures from lung biopsy and cervical lymph node homogenate. (A) Lung biopsy sample cultured on Sabouraud agar at 35°C showed round gray Talaromyces marneffei colonies. (B) Lung biopsy sample cultured on Sabouraud agar at 28°C showed a mycelial form producing a diffusible red pigment. Both (C) and (D) show colonies of Mycobacterium abscessus (black arrows) from cervical lymph nodes after incubation for 7 and 10 days, respectively.