A study in lung cancer patients showed that giving thymosin‑alpha‑1 (thymalfasin) lowered the number of immune‑suppressing cells (MDSCs) in the blood and tumor tissue, which could help the body fight the cancer better.

To observe the effect of thymalfasin on myeloid-derived suppressor cells (MDSCs) subsets in peripheral blood of patients with non-small cell lung cancer (NSCLC). 50 cases of NSCLC (NSCLC group) diagnosed in Chest Hospital of Jiangxi Province were selected as the research subjects, and 50 healthy subjects who underwent physical examination in our hospital during the same period were selected as the healthy control group. The expression of HLA-DR-CD14-CD33⁺ MDSCs in peripheral blood mononuclear cells and tumor tissue single cell suspension of NSCLC patients before and after thymalfasin treatment was explored by flow cytometry. The proportion of MDSCs in peripheral blood of NSCLC group was 1.70±0.52%, which was significantly higher than that in peripheral blood (0.51±0.15%) of healthy controls (P < 0.05). The proportion of HLA-DR-CD14-CD33⁺ MDSCs in the tissues of NSCLC group was 1.65±0.43% before treatment and 1.15±0.50% after treatment (P < 0.05). The proportion of MDSCs in peripheral blood of NSCLC patients before treatment was 1.70±0.52%, and that after treatment was 0.59±0.18% (P < 0.05). Thymalfasin can reduce the number of MDSCs in peripheral blood mononuclear cells. The application of thymalfasin in the treatment of NSCLC patients can help to enhance the anti-tumor effect.