Digital PCR detection of Mycobacterium tuberculosis, HIV-1 co-localization and reciprocal expansion in spinal tuberculosis biopsies
- Author(s)
- Waters, R; Martineau, AR; Laubscher, M; Dunn, RN; Held, M; Abrahams, MR; Coussens, AK;
- Journal Title
- International Journal of Infectious Diseases
- Publication Type
- Nov 11
- Abstract
- OBJECTIVES: The paucibacillary nature of spinal TB challenges diagnosis. Tissue sites of Mycobacterium tuberculosis (Mtb) and HIV-1 co-infection are suggested to favour reciprocal replication, and reservoir expansion, including in people living with HIV-1 (PLWH) on antiretroviral treatment (ART), yet evidence is scant. This study aimed to evaluate the utility of droplet digital PCR (ddPCR) to detect and quantify Mtb DNA in spinal biopsy tissue, with sensitivity validated against culture and Xpert MTB/RIF Ultra, and determine whether Mtb, and reciprocally HIV-1, DNA abundance is increased in sites of spinal co-infection. METHODS: 93 spinal biopsies segments from adults (≥18 years; n=25, 52% PLWH on ART) with presumptive spinal TB in South Africa had DNA extracted and ddPCR quantified copies of Mtb complex (MTBC) (rpoB, IS6110), HIV-1 (pol, gag) and Human (RPP30) genes. RESULTS: ddPCR detected MTBC DNA in biopsies from 10/10 (100%) culture-confirmed STB, 5/6 (83%) Xpert Ultra-confirmed STB and 4/9 (44%) culture and Xpert MTB/RIF Ultra negative patients (all 4 had previous pulmonary TB). Detected MTBC ranged from 8-59144 rpoB copies/biopsy. RpoB copies/10(6) human cells were higher in biopsies from PLWH (p=0.0096) and positively correlated with matched biopsy segment HIV-1 pol copies/10(6) cells (r=0.40; p=0.0003), and not peripheral viral load (VL). HIV-1 pol copies/10(6) cells were higher in segments with MTBC DNA co-detected (p=0.011) and also correlated with VL (r=0.91; p=0.0003). CONCLUSIONS: DdPCR has high sensitivity for STB diagnosis. Confirming reciprocal relationships exists between Mtb and HIV-1 abundance in spinal tissue in PLWH on ART, supports characterising the immune microenvironment in co-infected tissue sites to elucidate factors that impact HIV-1/Mtb reservoir persistence and/or expansion.
- Publisher
- Elsevier
- Keywords
- DNA; HIV reservoir; Mtb; Stb; Tb-hiv; biopsy; bone; co-infection; ddPCR; diagnostic; tissue
- Research Division(s)
- Infection and Global Health
- Publisher's Version
- https://doi.org/10.1016/j.ijid.2025.108204
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 2025-12-02 09:39:29
Last Modified: 2025-12-02 09:40:42