Abstract / Summary
Background The devastating pandemic of coronavirus disease 2019 (COVID-19) highlighted the importance of early detection and global collaboration in combating infectious diseases. Namibia is one of the countries that bears a high burden of tuberculosis (TB) and human immunodeficiency virus (HIV) infection. The overlap of these diseases underscores the need to better understand host immune responses, which play a critical role in disease pathogenesis and may differ across infections. This study aimed to profile selected cytokines and chemokines among Namibian individuals with TB, latent TB infection (LTBI), COVID-19, and HIV infection. Methods A cross-sectional study was conducted between August 2022 and May 2023 among adults (≥18 years) recruited from two clinics in Namibia. 222 participants were categorized into multiple clinical groups, including mono- and co-infections of COVID-19, active TB, LTBI, HIV, and control participants. Serum concentrations of 23 cytokines and chemokines were measured using the LEGENDPlex™ multiplex immunoassay. Differences, discriminations and correlations in biomarker levels between groups were analysed using non-parametric statistical tests with adjustment for multiple comparisons. Statistical significance was defined as an adjusted p < 0.05. Results MCP-1 demonstrated consistent upregulation across active TB, COVID-19, COVID-19/LTBI, and HIV/LTBI groups. In contrast, free active transforming growth factor beta 1 (TGF-β1) was significantly downregulated in both TB and LTBI participants. Individuals with TB exhibited elevated MCP-1 and macrophage migration inhibitory factor (MIF) levels compared to those with LTBI, with both analytes demonstrating discriminatory performance between TB and LTBI. Multiple moderate and weak positive correlations among inflammatory markers were observed in individuals with LTBI and HIV/LTBI but were absent in active TB and COVID-19/LTBI participants. Conclusions Our findings demonstrate distinct serum cytokines and chemokines across TB, LTBI, HIV, and COVID-19 in a Namibian cohort. MCP-1 emerged as a consistent marker associated with inflammation. MIF was detected as a potential differentiating marker for TB and LTBI. Larger studies are needed to evaluate the diagnostic potential of these biomarkers and their incorporation into clinical diagnostic algorithms. The results also suggest a possible role for LTBI-associated immune activation in HIV co-infection, which warrants further investigation.