Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio as haematological indices of inflammatory response in ceramic workers' silicosis

Introduction Occupational exposure to crystalline silica over time may result in silicosis: a fatal, irreversible occupational disease leading to lung function impairment. A complex inflammatory process, excessive accumulation of mesenchymal cells and collagen production are the primary mechanisms underlying silicosis. Neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) have emerged as representative indices of systemic inflammation. Objectives The purpose of the present study was to investigate the relationship between NLR, PLR and silicosis. Methods We retrospectively analysed the demographic and laboratory data of ceramic workers who were referred to our Hospital between 2010 and 2018. Five hundred and seventy-three patients with silicosis and 222 ceramic workers without silicosis (controls) were included in the study. Results The radiographic ILO classification of silicosis patients was as follows: category 1 (71.5%), category 2 (19.2%), category 3 (7.5%). NLR and PLR in categories 2 and 3 were significantly higher when compared with the control group (P < .005). FEV1, FEV1%, FVC, FVC % and PEF were significantly lower in all silicosis patients and also in patients with subcategories (all P < .005). NLR showed a poor positive correlation with CRP (r = 0.095, P < .05) and ESR (r = 0.207, P = .000) while PLR only with ESR (r = 0.317, P = .000) in patients with silicosis. NLR and PLR showed negative correlations with FEV1, FVC and PEF (all P < .005). Conclusion We conclude that NLR and PLR have significant but poor correlations with pulmonary functions and severity of silicosis, especially in late radiographic profusion categories.