Objective:To study the effect of immunomodulation on improvement of immune function and prognosis in sepsis  in rats, and its mechanism.
Methods:Experimental part: cecal ligation-perforation (CLP) models were divided into three groups including sham group (n=20), control group(n=20) and experimental group(n=20).Control group only used antibiotic and experimental group used antibiotic plus immunomodulation. Blood collections were made after CLP model at 3, 12, 48 and 72hr. Lymphocyte counting, CD4+, CD8+ T lymphocyte and CD4/CD8 ratio were checked. The apoptosis of lymphocyte in thymus and spleen and survival rate were checked. Clinical part: Prospective analysis of seventy patients who conformed to the sepsis standard. They were divided into two groups randomly. One was control group with regular therapy,  and the therapy group with ulinastatin plus thymosin-α1 for 7days. The immune index before and after therapy at 0, 1d, 3d, and 7d was observed, including the clinical changes and survival data.
Results:Experimental part: Lymphocytes, CD4+ T lymphocytes and CD4/CD8 ratio in experimental group increased more significantly than in control group(P＜0.05). Lymphocyte apoptosis index of thymus and spleen in control group increased more significantly than in experimental group(P＜0.05).Seventy-two hour survival in experimental group was longer than in control group. Clinical part: CD4+T lymphocytes, lymphocytes and monocytes HLA-DR CD14+ were more significantly increased in therapy group than that in control group(P＜0.05).During hospitalization, twenty patients died in the control group and thirteen patients died in the therapy group(P＜0.05).
Conclusions:Immunomodulation in septic rat can improve immune function, alleviate the lymphocyte apoptosis of thymus and spleen and increase the survival time. Immunomodulation in septic patients can improve the immune paralysis and prolong survival.