In people with silicosis, a lung disease caused by inhaling silica dust, the immune cells CD3+, CD4+, and CD8+ are lower than normal. Adding the peptide thymosin‑alpha‑1 (called thymalfasin) to standard treatment raised the number of CD4+ T‑cells after just one week, suggesting it can boost a specific part of the immune system in this sick group.

This study aims to investigate the changes in CD3⁺, CD4⁺ and CD8⁺ expression in cells in peripheral blood of silicosis patients, and observe the immunoregulatory effect of thymalfasin. A total of 80 silicosis patients were enrolled in the study, randomly divided into two groups: treatment group and control group (n=40, each group). In addition, 40 healthy adults, who underwent physical examinations in our hospital, were enrolled into the health examination group. Patients in the control group and treatment group were given anti-infection treatment, according to their conditions. Patients in the treatment group additionally received thymalfasin. Then, the number of peripheral blood T lymphocyte subsets in subjects in all three groups before and after treatment was measured. (1) Before treatment, CD3⁺, CD4⁺ and CD8⁺ levels in cells were significantly lower in the treatment group and control group than in the health examination group, and the differences were statistically significant (<i>P</i>&lt;0.05). (2) In the treatment group, the number of CD4⁺ cells in peripheral blood was significantly higher after one week of treatment, when compared to that before treatment, and the difference was statistically significant (<i>P</i>&lt;0.05). In silicosis patients, CD3⁺, CD4⁺ and CD8⁺ cells in peripheral blood are decreased, and thymalfasin can significantly increase CD4⁺ cells in peripheral blood of silicosis patients.