Short-term associations of PM and PM constituents with immune biomarkers: A panel study in people living with HIV/AIDS.

Studies on associations of fine particulate matter (PM) with immunity in people living with HIV/AIDS (PLWHA) were absent. We aimed to explore whether changes of immune biomarkers were associated with short-term exposure to PM in PLWHA. Based on a panel study in Wuhan, we selected 163 PLWHA as participants with up to 4 repeated visits from March 2020 to January 2021. Immune biomarkers, including CD4T cell count, CD8T cell count, HIV viral load (VL) and CD4T/CD8T ratio were tested for all participants at each visit. Residential exposures of PM and PM constituents for each participant were assessed using spatial-temporal models. Linear mixed-effect models and general linear mixed models were applied to evaluate the associations between PM and immune biomarkers. To estimate the combined effect of PM constituents, weighted quantile sum regression and Bayesian kernel machine regression were employed. Each 10 μg/m increase of 7-day average PM concentrations was associated with an 8.75 cells/mm (95%CI: -15.55, -1.98) decrease in CD4T cell count and a 92% (OR: 1.92, 95%CI: 1.43, 2.58) increased odds ratio of detectable HIV VL. However, the odds ratio of inverted CD4T/CD8T was only positively associated with PM concentrations at lag2 day (OR:1.27, 95%CI:1.02, 1.57). CD4T may be a potential mediator between PM and detectable HIV VL with 3.83% mediated proportion. Besides, the combined effect of PM chemical constituents indicated that NO and SO were the main constituents in reducing CD4T cell count and increasing odds ratio of detectable HIV VL. Our finding revealed that short-term exposure to PM was negatively associated with CD4T cell count but positively related to the odds ratio of detectable HIV VL in PLWHA. This research may provide new evidence in associations between PM and immune biomarkers as well as improving prognosis of PLWHA.