Abstract: Objective: To analyze the distribution of T lymphocyte subsets in peripheral blood of the systemic lupus erythematosus(SLE) patients, and to clarify its relationships with SLE disease activity and prognosis. Methods: The peripheral blood of 100 patients with primary SLE was collected, the counts of T lymphocyte subsets in the patients with different clinical subtypes of SLE (kidney involvement, skin involvement, joint involvement,hematological system involvement and different disease activity stages) were analyzed, and the relationships between the clinical indexes and the T lymphocyte subsets in the patients with primary SLE at baseline were evaluated.A total of 78 among 100 patients were followed up for 12 months, among them 26 patients had poor prognosis;the counts of T lymphocyte subsets in the patients with SLE were compared between poor prognosis group and clinical remission group. The correlations between the counts of T lymphocyte subsets in the SLE patients and the clinical indexes were analyzed by Spearman correlation test. Results: The counts of CD3+ T lymphocytes, CD4+ T lymphocytes and CD8+ T lymphocytes of the SLE patients in lupus nephritis group were lower than those in non-lupus nephritis group (P<0.05), the counts of CD3+ T lymphocytes and CD4+ T lymphocytes in the SLE patients in joint involvement group were lower than those in non-joint involvement group (P<0.05), the count of CD8+ T lymphocytes of the SLE patients in skin involvement group was lower than that in non-skin involvement group (P<0.05), and the counts of CD3+ T lymphocytes,CD4+ T lymphocytes and CD8+ T lymphocytes of the SLE patients in hematological system involvement group were lower than those in non- hematological system involvement group (P<0.05). The counts of CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes of the SLE patients were negatively correlated with the SLE disease activity index(SLEDAI) score (r=-0.391, P=0.001; r=-0.360, P=0.002; r=-0.315, P=0.008); the counts of CD3+ T lymphocytes, CD4+ T lymphocytes,and CD8+ T lymphocytes were positively correlated with the plasma C3 level of the SLE patients (r=0.407, P=0.001; r=0.395, P=0.001; r=0.254, P=0.035); the counts of CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes were positively correlated with the lymphocyte (LY) level in peripheral blood of the SLE patients (r=0.717,P=0.000;r=0.617,P=0.000;r=0.599,P=0.000);the counts of CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes of the SLE patients in severe activity group were significantly lower than those in mild activity group(P<0.05);the counts of CD3+ T lymphocytes and CD4+ T lymphocytes of the SLE patients in poor prognosis group were lower than those in clinical remission group (P<0.05). Conclusion: The distribution of T lymphocyte subsets of the SLE patients in different subgroups is different, and it is closely associated with the SLE disease activity;the low count of CD4+T lymphocytes is associated with the poor prognosis of SLE patients, which may be a marker of SLE disease activity and prognostic judgment.

Key words: systemic lupus erythematosus, T lymphocyte subsets, disease activity, poor prognosis