Objective:To investigate the guiding significance of monitoring of immune factors and T lymphocyte subsets in immunomodulatory treatment of sepsis.Methods:Eighty patients with sepsis admitted to Nangyang First People's Hospital from June 2022 to December 2023 were selected as sepsis group,and 80 healthy volunteers who underwent physical examination during the same period were selected as health group.Detection of immune factors[complement C3,IgA,IgG,IgM,IFN-γ,programmed cell death receptor-1(PD-1)]and T lymphocyte subsets(CD4+,CD8+,CD4+/CD8+)on the day of physical examination in healthy group,the day after sepsis group was enrolled,before treatment,and on day 1,3,and 7 after treatment,expressions of immune factors and T lymphocyte subsets were compared between the two groups.All 80 patients with sepsis received comprehensive treatment,during which thymosine-α1 was added for immunoconditioning treatment.Patients were divided into groups according to the improvement of their condition after immunoconditioning treatment[low-risk group(n=31),medium-risk group(n=34),high-risk group(n=15)]and disease outcome[survival group(n=55)and death group(n=25)].To analyze the efficacy of immune factors and T lymphocyte subsets in predicting the condition improvement and disease outcome of patients with sepsis after immune conditioning treatment.Results:Compared with healthy group,expression levels of immune factor complements C3,IgA,IgG,IgM and IFN-γ in sepsis group were decreased,relative expression level of PD-1 mRNA was increased,the values of CD4+T and CD4+T/CD8+T of T lymphocyte subsets were decreased,while CD8+T was increased(P<0.05).Compared with before treatment and 1 day after treatment,expression levels of complements C3,IgA,IgG,IgM,IFN-γ,CD4+T and CD4+T/CD8+T of T lymphocyte subsets were significantly increased in patients with sepsis after treatment on 3 and 7 days,while the relative expression level of PD-1 mRNA and CD8+T were significantly decreased(P<0.05).Condition of sepsis patients improved significantly after immune conditioning treatment,that is,proportion of low-risk patients increased,and proportion of medium-risk patients and high-risk patients decreased(Z=6.954,P<0.05).Levels of C3,IgA,IgG,IgM,IFN-γ,CD4+T and CD4+T/CD8+T in high-risk groups were significantly decreased,while PD-1 and CD8+T were significantly increased in low-risk and medium-risk groups(P<0.05).Levels of C3,IgA,IgG,IgM,IFN-γ,CD4+T and CD4+T/CD8+T in death group were significantly lower than those in survival group,while PD-1 and CD8+were significantly increased(P<0.05).ROC curve analysis showed that AUC of the combination of immune factors and T lymphocyte subsets to predict the improve-ment of the condition of sepsis patients after immune conditioning treatment was 0.923,the sensitivity was 89.90%,and the specificity was 82.31%.The efficacy of predicting the disease outcome of sepsis patients after immune conditioning treatment showed that the pre-dicted AUC was 0.965.The sensitivity was 95.60%and the specificity was 86.57%,which were obviously better than the single item.Conclusion:Sepsis patients have immune dysfunction related to immune factors and abnormal T lymphocyte subsets,immunomodu-latory therapy can help improve immune dysfunction,monitor immune factors upon admission,and levels of T lymphocyte subsets are helpful for early prediction of disease progression and prognosis in sepsis patients after immunomodulatory therapy.