Objective To explore the value of macrophage inflammatory protein-1α (MIP-1α) in early diagnosis of coal workers' pneumoconiosis by establishing a receiver operating characteristic (ROC) curve model.
Methods Serum levels of MIP-1α were determined by enzyme-linked immunosorbent assay (ELISA) in 180 suspected silicosis patients with small lung opacity (observation group), 180 silica dust exposed workers without pneumoconiosis (dust exposed group), and 109 stage Ⅰ pneumoconiosis patients (case group). Evaluation of serum MIP-1α detection in screening coal workers' pneumoconiosis was using ROC curve analysis.
Results By analysis of covariance, controlling for age, the serum levels of MIP-1α in the case group were significantly higher than those in the exposed group and the observation group (P<0.05); and the levels of MIP-1α in the observation group were significantly higher than those in the exposed group (P<0.05). When stratified by seniority, the levels of MIP-1α in the case group were significantly higher than those in the observation group or in the exposed group for dust exposure duration of 10-years, 20-years, or 30 to 38 years (P<0.05); the levels of MIP-1α in the observation group were significantly higher than those in the exposed group for the above three durations (P<0.05). The MIP-1α level increased with seniority for the three groups. The ROC analysis indicated the area under the ROC curve was 0.874, the optimal criterion value was 940.85 ng/L, the sensitivity was 75.2%, the specificity was 90.0%, the missed diagnosis rate was 24.8%, the misdiagnosis rate was 10%, the Youden index was 65.2%, the positive likelihood ratio was 7.52, the negative likelihood ratio was 0.28, the agreement was 0.87, the Kappa value was 0.63, the positive predictive value was 69.49%, the negative predictive was 92.31%, and the yield was 36 people.
Conclusion MIP-1α as a screening indicator has the advantages in high validity and reliability, and therefore can be used for coal workers' pneumoconiosis early diagnosis.
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