674 Assessment of serum and urinary biomarkers for pneumoconiosis in a cohort of stone workers exposed to asbestos contaminated minerals

Abstract

Introduction Pneumoconiosis resurged in recent years but current medical surveillance programs have flaws that result in low detection rate. Development of new screening tools is warranted. The objective of the study was to develop serum and urinary screening tests for pneumoconiosis. Methods We conducted a cross-sectional study in 140 stone workers between March 2013 and July 2014. We compared serum soluble mesothelin-related peptide (SMRP), fibulin-3, and urinary 8-Oxo-2’-deoxyguanosine (8-OHdG)/Creatinine between cases of pneumoconiosis and control. Using the ILO international classification of radiographs of pneumoconiosis profusion subcategory ≧1/0 combined with restrictive type ventilatory impairment in standard pulmonary function test (FVC 70% of predicted) as the reference standard, we calculated sensitivity, specificity, false positive, false negative, and the likelihood ratio of the biomarkers. We created the receiver operating characteristic (ROC), calculated the area under the curve (AUC) and decided the cut-off values using the Youden index. Results After excluding one subject with uremia and one subject with COPD, a total of 138 subjects were enrolled that included 20 cases and 118 controls. The ROC-AUC was 0.7 for SMRP (95% CI: 0.5 to 0.8), 0.5 for Fibulin-3 (95% CI: 0.4 to 0.7), and 0.5 for 8-OHdG/Creatinine (95% CI: 0.4 to 0.6). There was a dose-response relationship between SMRP and the severity of pneumoconiosis. Using SMRP larger than 0.62 nM as the cutoff value, the diagnostic test had the highest positive likelihood ratio followed by using fibulin-3 larger than 43.9 ng/mL as cutoff value, and then101.65 ng/mg for 8-OHdG/Creatinine. In the case group, 65% of subjects processed asbestos-contaminated ores including nephrite, antigorite, or talc. Subjects exposed to nephrite had significantly higher level of SMRP than exposed to other types of stones. Conclusion SMRP might be used in the screening for workers exposed to asbestos contaminated minerals.