e21203 Background: Radiotherapy (RT), surgical resection (SR), and immunotherapy (IT) as main therapies in lung cancer have either suppressive or stimulatory effects on the immune system. It’s still unclear the mechanism involved in the systemic changes of immune cells in the blood. Peripheral blood lymphocyte subpopulations were useful markers for evaluating immune response in tumor patients. Hence, we aimed to systematically investigate the alteration of lymphocyte subpopulations during the local therapies to evaluate antitumor treatment effects. Methods: Blood samples were obtained EDTA coated tubes and then centrifuged gently for white blood cell separation. The white blood cells in 10% DMSO and 90% FBS were frozen slowly in -80°C refrigerator. The following fluorochrome-conjugated surface and nuclear antibodies were used in the lymphocyte subtyping: CD11b, CD45, CD19, CD3, CD56, CD4, CD8a, CD25,CD127 and FOXP3. The staining cells were detected in the BD FACS machine and data were analyzed by the paired T-test. The percentage of Lymphocytes, Myeloid cells, B cells, T cells, Treg, CD8+ T cells, CD4+ T cells, NK cells, and NKT were examined. Results: Between July 2019 and January 2020, a total of 176 patients eligible, including 135 RT patients and 29 SR patients,12 IT patients, with both blood collection with both Pre, During and End therapies. Before local therapies, the percentage of total T cells in the RT group was significantly higher than SR (RT v.s SR mean:64.1 v.s 55.3, P = 0.02) while CD8+ T cells (RT v.s SR mean:28.2 v.s 34.5, P = 0.04)and Tregs (RT v.s SR mean:0.0 v.s 0.1, P = 0.055) were lower. The baseline level of T cells and their subtypes showed a significant difference in these two group patients. After local therapies, myeloid cells, lymphocytes, CD4+ T cells, CD8+ T cells, NK cells were significant different. There is no significant difference due to the smaller number of IT patients. In the RT group, lymphocytes (Pre-RT v.s End-RT mean:75.2 v.s 54.3, P = 0.004) and B cells (Pre-RT v.s End-RT mean:12.6 v.s 8.0, P = 0.03) were significantly decreased while other subpopulations didn’t show any significant difference after RT. Interestingly, in the SR group, there was a significant increase in CD4+ T cells (mean:59.0 v.s 62.1, p = 0.02) a trend of reduction in CD8+ T cells (mean:34.5 v.s 32.0, p = 0.055) after SR. In addition, there was an increased trend of Tregs after IT. Conclusions: There are some different patterns of distribution in subtypes of leukocytes in operable and inoperable patients and between different therapies. All RT, SR and IT changed the distribution of peripheral blood lymphocyte subpopulations. Further validation study is warranted to validate our findings particularly in circulating lymphocytes and B cells as a marker to evaluate immune status after RT, CD4+ T cells and CD8+ T cells after SR, Tregs after IT, as well as their relationship with tumor microenvironment and implication for personalized care.
CD8+ T Cells Form the Predominant Subset of NKG2A+ Cells in Human Lung Cancer