Objective To explore the effect of radiotherapy on lymphocytes in peripheral blood before and after chemoradiotherapy in patients with acquired immune deficiency syndrome (AIDS) complicated with malignant tumors.

Methods From June 2017 to June 2022, a total of 18 AIDS patients with malignant tumors in authors' hospital were selected as observation group; 18 non-AIDS patients with malignant tumors were selected as control group; 18 healthy people with physical examinations were selected as healthy control group. Flow cytometry was used to detect the cell ratios of CD4⁺ and CD8⁺ in peripheral blood in each group, and the ratio of CD4⁺ to CD8⁺ (CD4⁺/CD8⁺) was calculated. The regression of tumors after 6 months of treatment was compared between groups.

Results Compared with the healthy control group, the CD4⁺ and CD4⁺/CD8⁺ in peripheral blood in the control group and the observation group decreased significantly, while the CD8⁺ increased significantly (P < 0.05); compared with the control group, the CD8⁺ increased significantly, while the CD4⁺/CD8⁺ decreased significantly in peripheral blood in the observation group (P < 0.05). One month after radiotherapy, the CD8⁺ in peripheral blood in the observation group was significantly higher than that in the control group (P < 0.05). Three months after radiotherapy, the CD4⁺ and CD4⁺/CD8⁺ in peripheral blood in the observation group were lower than those in the control group, but there were no significant differences between two groups (P>0.05); the CD8⁺ in peripheral blood in the observation group was slightly higher than that in the control group, and there was no significant difference between twogroups (P>0.05). In the intragroup comparison in the control group, the CD4⁺/CD8⁺ in peripheral blood at one month after radiotherapy was significantly lower than that before radiotherapy, while CD8⁺ was significantly higher than that before radiotherapy (P < 0.05); there were no significant differences in CD4⁺, CD8⁺ and CD4⁺/CD8⁺ in the peripheral blood between each time point in the observation group (P>0.05). After 6 months, CT or magnetic resonance imaging was re-examined. In the observation group, there were 10 cases with reduced or no change in tumor tissue, 5 cases with increased tumor tissue or lymph node metastasis, and 3 cases with new metastatic lesions except for lymph nodes; in the control group, there were 13 cases with reduced or no change in tumor tissue, 4 cases with increased tumor tissue or lymph node metastasis, and 1 case with new metastatic lesions except for lymph nodes. There was no significant difference in regression of tumor between the observation group and the control group (P>0.05).

Conclusion The effect of radiotherapy on the lymphocyte subpopulations in AIDS patients with malignant tumors shows no significant difference compared with those of non-AIDS patients with malignant tumors. Therefore, radiotherapy should be more frequently applied in the treatment of AIDS patients with malignant tumors.