Peripheral blood lymphocyte cell subsets in subjects with silicosis due to silica agglomerates

Few studies have been reported on the lymphocyte subsets in patients with silicosis. In particular, none has been published on patients with silicosis due to silica agglomerates (SA), a type of artificial stone. <bold>Aim:</bold> to characterize lymphocyte subsets in the peripheral blood of patients with silicosis due to SA. <bold>Methods:</bold> 91 patients diagnosed with silicosis due to SA were included, 53 with simple silicosis (SS), 38 with complicated silicosis (CS) and 23 healthy unexposed as a control group (CG). All were men. Main age 40.1 ±7.7 (SS), 41 ± 6.2 (CS) and 36.4 ±8.3 (CG). Cell subsets from blood samples were analyzed by flow cytometry. <bold>Results:</bold> The main subsets of leukocytes in peripheral blood, such as neutrophils and monocytes, progressively increased in patients with SS and CS compared with the CG. However, in the case of lymphocytes the opposite was observed, so that the percentage of lymphocytes in the GC was 31.3±8.2, 25.6±7.6 (SS) and 22.6±5. 8 (CS) with statistically significant differences. Analyzing the main subsets of lymphocytes, the following differences were observed in patients with silicosis compared to CG: i) a significant decrease in the percentage of memory B cells (30±13.6 [CG], 19.1±9, 4 [SS], 21.1±12.2 [CS]) and an increase in plasma cells (0.07±0.06 [CG], 0.11±0.08 [SS], 0.1± 0.04[CS]; ii) a significant reduction in the proportion of naïve Th cells (32.5±13.5 [CG], 23.5±10.1 [SS], 25.8±9.6 [ CS]); iii) a significant increase in memory Th cells (43.6±13.2 [CG], 54.4±14.6 [SS], 53.3±12.5 [CS]). <bold>Conclusions:</bold> Some subsets of lymphocytes are altered and could be targeted as possible new avenues of intervention to treat the disease. <bold>Grants:</bold> FPS: 201800016448‐TRA, ISCIII:PI19/01064