CD14基因多态性与严重烧伤患者T淋巴细胞免疫功能的相关性研究

目的 探讨严重烧伤患者CD14基因多态性与T淋巴细胞免疫功能的关系.方法 采集77例烧伤体表总面积大于30%患者血标本,通过聚合酶链反应.限制性片段长度多态性方法检测CD14-159C/T基因多态性,观察其外周血T淋巴细胞增殖反应和白细胞介素-2(IL-2)的产生能力,并通过流式细胞仪检测T淋巴细胞CD4+/CD8+的比值、CD4+细胞的凋亡率.结果 严重烧伤后患者T淋巴细胞增殖能力明显下降,与CC纯合子患者比较,TT、TC基因型患者伤后第5、21、28天T淋巴细胞对丝裂原刺激增殖反应显著受抑(P<0.05或P<0.01).烧伤后携带TC、TT型患者IL-2产生一直处于较低水平,而CC型在伤后14 d分泌IL-2逐渐上升.与CC型患者比较,携带TT、TC型患者T淋巴细胞比值均降低,尤其在伤后第1、3、14、21、28天差异明显(P<0.05或P<0.01).三型CD3+CD4+T淋巴细胞凋亡率比较,TT型患者伤后第5、7、21天凋亡率显著高于CC型患者(P<0.05),TC型患者伤后7、14 d其凋亡率高于CC型患者(P<0.05),而,TT、TC型之间上述免疫功能指标比较均无显著差异(P>0.05).结论 CD14-159C/T多态性可影响大面积烧伤患者T淋巴细胞免疫功能状态,进而参与了严重感染并发症的发生与发展过程.

Study on the correlation between CD14 gene polymorphism and T ceil-mediated immunity in severely burned patients

Objective To investigate the correlation between CD14 gene polymorphism and T cell-mediated immunity in severely burned patients. Methods The blood samples of 77 patients with extensive burn injury (>30% total body surface area) were collected, and CD14-159C/T gene polymorphism was determined by polymerase chain reaction-restrictian fragment length polymorphism (PCR-RFLP). T lymphocyte cell proliferation and interleukin-2 (IL-2) production were determined, and the ratio of CD4+/CD8+ T lymphocyte as well as apoptosis of CD4+ T lymphocyte was examined by flow cytometry. Results The ability of T lymphocyte proliferation was obviously decreased in severely burned patients. Compared with CC homozygote patients, proliferative activity of T lymphocyte to mitogen stimulation was significantly depressed in Tr and TC patients on post burn days 5, 21, and 28 (P < 0. 05 or P < 0. 01). IL-2 production in Tr, TC patients was constantly in low level after burns, while it was increased from post burn day 14 in CC patients. The ratio of CD4<'+>/CD8<'+> T lymphocytes was markedly decreased in TC, TT patients than that in CC patients, especially on post burn days 1, 3, 14, 21, and 28 (P < 0. 05 or P < 0.01). Meanwhile, compared with CC homozygote patients, the apoptosis rates of CD3<'+> CD4<'+> T lymphocytes were much higher in TT patients on post burn days 5, 7, and 21 (P < 0. 05), and in TC patients on days 7, 14 (P <0. 05), respectively. However, no obvious differences in parameters of immune function of T lymphocytes were found between TY and tic patients (P > 0. 05). Conclusion CDI4-159C/T polymorphism could influence the T cell-mediated immunity in extensively burned patients, which might participate in the development of septic complications secondary to major burns.