The Effects Of Chemoradiotherapy To PD-1 On Circulating T Lymphocytes And Related Immune Indexes From Nasopharyngeal Carcinoma

ObjectiveInvestigations have showed that the immune suppression and inability played an important role in the occurrence and development of tumor.Chemoradiotherapy significantly improved the survival of nasopharyngeal carcinoma(NPC)patients.However,chemoradiotherapy kill the tumor cells as well as the immune system cells.But,the immunity condition of NPC patients before and after treatment were still unknown,especially the expression levels of PD-1 on the T cells.The study was to explore the immune status of NPC in different treatment time by dynamically monitoring the expression levels of PD-1 on the T cells and related immune index from peripheral blood.Methods165 NPC patients and 67 healthy controls were included in this study.In addition,88 cases of retrospective data of NPC patients at 6 months after the completion of treatment in our hospital was also included in the study.The expression levels of PD-1 and related immune index in peripheral blood were detected by the flow cytometry.ResultFirst,we analyzed the difference about immune state between NPC group and control group.The result showed the proportion of CD3+cell,CD4+T cell,B cell,CD8+CD28+T cell,natural killer cell(NK cell),CD3+HLA-DR+ cell and CD4/CD8 ratio in NPC group were significantly changed(P<0.05).The surface expression of PD-1 on theT cells in NPC group was significantly higher than healthy control.There were no significant correlation between the expression of PD-1 and clinical characteristics,such as age,sex,tumor burden and clinical stage(P > 0.05).Secondly,we analyzed the immune state of NPC patients underwent the neoadjuvant chemotherapy.The result showed the proportion of CD3+cell,CD4+T cell,CD8+CD28+T cell and CD4/CD8 ratio in NPC group were significantly up-regulated.And the proportion of NK cell,B cell were significantly down-regulated(P<0.05).Thirdly,we analyzed the immune state of NPC patients underwent the radiotherapy.The result showed the proportion of CD8+T cell and NK cell in NPC group were significantly up-regulated.And the proportion of CD4+T cell,B cell and CD4/CD8 ratio were significantly down-regulated(P<0.05).The proportion of PD-1+T cell were up-regulated and CD3+HLA-DR+ cell were down-regulated significantly(P<0.05).Lastly,we analyzed the immune state of NPC patients at 6 months after the completion of treatment.The result showed the proportion of B cell,PD-1+T cell and CD8+CD28+T cell were significantly higher than those at the end of radiotherapy(P<0.05).Conclusions1.The immune function of NPC patients had significantly decrease,especially the immune function of T and B cell might be depressed in these patients.2.The neoadjuvant chemotherapy showed better effect on the immune system.3.Immune function of NPC patients had been suppressed after the radiotherapy.4.The suppression of Immune function was still ongoing within 6 months after the completion of treatment and the depressed state might last longer.