目的:研究再生障碍性贫血(AA)患者外周血中的T细胞亚群变化与血清中1,25-(OH)_2维生素D3水平的关系。方法:利用流式细胞仪检测15例AA患者和25例健康对照者外周血T细胞亚群的变化,并用ELISA法检测AA患者和健康对照者血清中1,25-(OH)_2维生素D3的水平。结果:AA患者血清中1,25-(OH)_2维生素D3水平明显低于健康对照者[(35.5±11.8)pmol/L∶(51.8±12.6)pmol/L,P<0.05]。与健康对照者比较,AA患者外周血中CD4在淋巴细胞中比率无明显变化[(31.8±4.7)%∶(33.6±4.2)%,P=0.217],但CD8在淋巴细胞中比率显著升高[(31.5±5.2)%∶(24.8±3.8)%,P<0.01],故CD4/CD8比值降低(P<0.01);其中在CD4~+细胞中,TH1/TH2比值较健康对照者明显升高[(4.09±1.05)∶(3.12±0.89),P=0.003]。结论:AA患者外周血清中1,25-(OH)_2维生素D3水平异常降低,可能影响AA患者CD4~+T细胞的分化。 Objective: To study the relationship between the change of T lymphocyte subsets in peripheral blood and serum 1,25- (OH) 2-D3 level in patients with aplastic anemia (AA). Methods: The changes of T lymphocyte subsets in peripheral blood of 15 patients with AA and 25 healthy controls were detected by flow cytometry. The serum levels of 1,25- (OH) 2-D3 in serum of AA patients and healthy controls were measured by ELISA Level. Results: The level of 1,25- (OH) 2 vitamin D3 in AA patients was significantly lower than that in healthy controls [(35.5 ± 11.8) pmol / L: (51.8 ± 12.6) pmol / L, P <0.05]. Compared with healthy controls, there was no significant change in the proportion of CD4 in lymphocytes in AA patients [(31.8 ± 4.7)% vs (33.6 ± 4.2)%, P = 0.217], but the percentage of CD8 in lymphocytes was significantly increased (31.5 ± 5.2)%: (24.8 ± 3.8)%, P <0.01], so the ratio of CD4 / CD8 decreased (P <0.01). The ratio of TH1 / TH2 in CD4 ~ + cells was significantly higher than that in healthy controls High [(4.09 ± 1.05): (3.12 ± 0.89), P = 0.003]. Conclusion: The abnormal level of 1,25- (OH) 2-D3 in peripheral blood of patients with AA is abnormally decreased, which may affect the differentiation of CD4 ~ + T cells in AA patients.