Diagnostic Value of Metagenomic next-generation sequencing and X-pert in Bronchoalveolar lavage fluid for pneumonia in HIV-infected and HIV-uninfected patients

The pathogens causing unexplained pneumonia in both HIV-infected or HIV-unfected patients are likely to be complex. This retrospective study aimed to characterize the etiology of pneumonia in HIV-infected and HIV-uninfected patients using bronchoalveolar lavage fluid (BALF) analysis with metagenomic next-generation sequencing (mNGS) and X-pert MTB/RIF. Between January 2022 and May2024, 141 HIV-infected and 104 HIV-uninfected patients admitted to Nanjing Second Hospital with pneumonia were included. BALF samples were collected and analyzed using mNGS to detect bacteria, fungi, viruses, tuberculosis (TB) and non-tuberculous mycobacteria (NTM), and X-pert for TB detection. Clinical data including CD4 T-cell counts, comorbidities, and ART status were collected and analyzed. HIV-uninfected patients were found to be older and exhibited a higher prevalence of comorbidities compared to HIV-infected patients. Despite higher median CD4 T-cell counts in HIV-uninfected individuals (412 cells/μL vs. 31 cells/μL in HIV-infected), TB detection rates using X-pert and mNGS were lower than anticipated, particularly in HIV-infected patients. Mixed-pathogen infections were significantly more prevalent in HIV-infected patients, especially those with lower CD4 T-cell counts. ART use showed variable impacts on pathogen diversity, with longer treatment durations associated with reduced infection complexity but persistent immunodeficiency in some cases. In patients with pneumonia, whether HIV-infected or HIV-uninfected, pathogens often exhibit complexity, underscoring the critical role of timely mNGS and X-pert analysis of BALF for early pathogen detection.