Abstract: Objective To analyze the changes of serum T lymphocytes in patients with infection after trauma blood transfusion and whether it is related to the patient's infection, and briefly analyze the risk factors of infection in such patients, in order to provide reference for infection prevention and whether immune monitoring is needed in such patients. Method 126 trauma blood transfusion cases admitted to Qinghai Provincial Fifth People's Hospital from January 2019 to May 2023 were included. The patients' serum T lymphocyte levels were measured before and after blood transfusion. According to whether the patients were infected, they were divided into infection group (43 cases) and uninfected group (83 cases), the serum T lymphocyte levels of the two groups were compared, and general information such as patient age, gender, trauma type, whether immunosuppressants were used, and red blood cell storage time were collected for single-factor analysis, and statistically significant results were analyzed. The data were included in the Logistic regression analysis model to complete the risk factor analysis of infection after trauma blood transfusion. Result After blood transfusion, the levels of CD3⁺T lymphocytes, CD4⁺T lymphocytes, and CD4⁺/CD8⁺ in patients were significantly reduced, while CD8⁺T lymphocytes were significantly increased (P<0.05); in the infection group, the levels of CD3⁺T lymphocytes, the levels of CD4⁺T lymphocytes and CD4⁺/CD8⁺ were significantly lower than those of the uninfected group, and the levels of CD8⁺T lymphocytes were significantly higher than those of the uninfected group (P<0.05); in the single-factor analysis of other general data, patients in the infected group had multiple injuries, use the proportion of immunosuppressants, receiving gastrointestinal decontamination treatment, average red blood cell storage time ≥14 days, and the total number of red blood cell transfusion units ≥7 was significantly higher than that of the uninfected group (P<0.05). The rest were smoking, alcohol abuse, age, gender, there was no significant difference in the average platelet storage time, whether combined with diabetes, and the total number of platelet transfusion units (P>0.05). Logistic regression analysis showed that CD8⁺T lymphocytes elevated, multiple injuries, use of immunosuppressants, and gastrointestinal decontamination treatment, average red blood cell storage time ≥14 days, and total number of red blood cell transfusion units ≥7 are independent risk factors for infection in trauma blood transfusion patients (OR>1, P<0.05), CD3⁺T lymphocytes, CD4⁺T lymphocytes, CD4⁺/CD8⁺ is a protective factor (OR<1, P<0.05). Conclusion After trauma blood transfusion, it is easy to have an impact on the patient's immune function. Infected patients after trauma blood transfusion have more obvious disorder of T lymphocyte subsets than uninfected patients. Patients with trauma blood transfusion need to pay attention to their immune monitoring to prevent infection.

Key words: T lymphocytes, Trauma, Blood transfusion, Infection, Risk factors