Case report: A special case of pneumonia with a novel STAT3 mutation and Talaromyces marneffei infection.

Background: Talaromyces marneffei (TM) is an opportunistic pathogenic fungus, primarily reported in patients with congenital immune deficiencies. STAT3, a key molecule involved in fungal immune surveillance, plays a critical role in defense against fungal infections. Mutations in the STAT3 gene are associated with increased susceptibility to such infections.

Presentation Of Case: An 11-month-old girl was admitted to our hospital with a 3-month history of recurrent coughing and wheezing and a recent 3-day history of hoarseness. Next-generation sequencing (NGS) and microbial culture of bronchoalveolar lavage fluid (BALF) samples confirmed a TM infection. Bronchoscopy revealed the presence of white pseudomembranous secretions. Whole-exome sequencing identified a novel mutation in the STAT3 gene. Following administration of amphotericin B antifungal therapy, the patient's clinical symptoms significantly improved.

Conclusion: In children with recurrent lung infections that are refractory to treatment, along with elevated IgE levels, clinicians should consider the possibility of underlying immunodeficiency and TM infection. NGS analysis of bronchoalveolar lavage fluid (BALF) is valuable for early diagnosis.