Abstract
BACKGROUND: Mycobacterial infections represent a major cause of morbidity and mortality in HIV-infected individuals. This study evaluated diagnostic techniques for mycobacterial identification and compared clinicopathological features between HIV-positive and HIV-negative patients. METHODS: We analyzed 88 tissue samples (with 41 matched blood and 28 sputum samples) using histopathology (HE and acid-fast staining), bacterial culture, MTB-PCR (sputum/biopsy), PCR-reverse dot blot hybridization (RDBH), and metagenomic pathogen detection technology (MetaPath™). Logistic regression analyses were performed to identify factors affecting detection rates. RESULTS: Mycobacterial infection was detected in 95.5% (84/88) of patients. Among HIV-positive patients (n=63), 46% (29/63) had Mycobacterium tuberculosis (MTB) infections, and 44% (28/63) had non-tuberculous mycobacteria (NTM) infections, significantly higher than the 20% (5/25) NTM rate in HIV-negative patients. Univariate analysis identified HIV-positive status (p=0.009), lymph node involvement (p=0.020), and positive MetaPath™ results (p=0.002) as significant predictors of detection, while multivariate analysis confirmed these as independent factors (p=0.036; p=0.042; p=0.006). Lymph nodes were the most common infection site in HIV-positive patients (42.9%, 27/63), while lung tissue predominated in HIV-negative patients (48%, 12/25). MetaPath™ demonstrated superior sensitivity and specificity for detecting both MTB and NTM. Biopsy samples provided higher diagnostic accuracy than sputum or blood for lung and lymph node infections, but not for brain. In HIV-positive patients, NTM infections showed significantly more granuloma formation (p=0.032) and foam cells (p=0.005), but less necrosis (p=0.0005) compared to MTB infections. No significant differences were observed in HIV-negative patients. CONCLUSIONS: MetaPath™ is a highly effective diagnostic tool for mycobacterial infections, particularly in tissue biopsies. HIV-positive status, lymph node involvement, and MetaPath™ positivity independently predict mycobacterial detection. HIV-positive patients exhibit distinct clinicopathological features, emphasizing the need for tailored diagnostic and therapeutic approaches based on immune status.