Platelet and IL-33 count as biomarkers for lung function impairment: An 11-year follow-up study on populations exposed to hexavalent chromium

Recent research has highlighted the crucial role of immune regulation in lung function impairment due to exposure to hazardous materials. This study aimed to identify dynamic network biomarkers for lung function damage caused by hexavalent chromium inhalation exposure, using immune-related indicators in blood. An 11-year follow-up longitudinal study was conducted on a population occupationally exposed to hexavalent chromate (Cr [VI]) from 2010 to 2020, consisting of sixty-one subjects with 328 repeat measurements. Quantitative analysis of immune-related indicators, including white blood cells, cytokines, and platelet count, was performed. The concentration of urinary Cr served as an indicator of internal exposure, confirming its association with lung function impairment. Dynamic network analysis revealed that platelet count was connected to neutrophils, IL-8, IL-6, and IL-33 when the exposure time was equal to or longer than 9.2 years (the median exposure time). Notably, the association between platelet count and IL-33 was specific to long-term (≥ 9.2 years) exposure. The areas under the receiver operating characteristic (ROC) curves (AUCs) for platelet count combined with IL-33 to predict lung function impairment in the long-term and short-term Cr [VI]-exposed populations were 80.5 % and 55.4 %, respectively. These findings provide evidence that the combination of platelets and IL-33 holds significant promise as biomarkers for predicting lung function impairment. Moreover, they shed light on the potential mechanism involving immune and hematopoiesis functions in the context of environmental hazardous exposure.