Pilot proteomics study for identifying a pollution exposure signature in firefighters

Abstract Background Recent studies showed that immune and cardiometabolic biomarker levels increased in individuals exposed to air pollution. Objective We sought to identify a pollution exposure signature in a pilot cohort of 54 firefighters and controls in the Bay Area. Methods We analyzed Olink-processed proteomics data under multiple approaches for feature selection, including the LASSO. We selected 67 biomarkers related to well-defined pathways for targeted analyses, whereas 1463 unique assays were considered for untargeted analyses. Results Levels of angiopoietin 1 and hydroxyacylglutathione hydrolase were consistently higher in firefighters compared to controls. Moreover, matrix metalloproteinase-1, a protein that promotes tumorigenesis, was higher at the visit with greater acute exposure. Fifteen other key biomarkers were jointly identified under untargeted and targeted approaches. Regression analysis found that 10 biomarkers were numerically higher in firefighters with high exposure. Significance These analyses demonstrate the potential utility of large-scale plasma proteomics in identifying a pollution exposure signature. Impact statement Exposure to particulate matter leads to proteomic changes that are associated with adverse health outcomes. Applying regularization-based feature selection methods to high-dimensional data can identify a small subset of biomarkers for targeted monitoring efforts. Our findings improve understanding of the implications of air pollution for healthy adults and serve as a foundation to developing strategies for mitigating occupational exposure.