目的 探讨负性调节细胞CD4⁺CD25⁺T及其相关细胞因子在慢性阻塞性肺病(COPD)患者外周血中的表达与合并细菌感染的相关性。方法 纳入2018年1月—2019年12月间收治的66例COPD患者作为研究对象,其中急性加重期COPD患者(AECOPD)36例、稳定期患者30例,并纳入同期体检健康者30例作为对照组。对所有纳入的研究对象外周血标本中的CD4⁺CD25⁺T调节性T细胞及其相关细胞因子[白介素-4(IL-4)、白介素-10(IL-10)、干扰素-γ(IFN-γ)]表达水平进行检测,分析相关指标水平与COPD是否合并细菌感染的关系,及预测细菌感染的效能。结果 AECOPD和稳定期COPD患者CD4⁺、CD4⁺CD25⁺、IFN-γ/IL-4水平均低于对照组(P<0.05),IL-4、IL-10水均高于对照组(P<0.05);AECOPD患者IFN-γ水平高于对照组(P<0.05);AECOPD患者CD4⁺、CD4⁺CD25⁺水平低于稳定期COPD患者(P<0.05),IL-4、IL-10、IFN-γ均高于稳定期COPD患者(P<0.05);CD4⁺、CD4⁺CD25⁺水平与IL4、IFN-γ均呈负相关关系(P<0.05),CD4⁺水平与IL-10呈负相关关系(P<0.05);COPD合并感染者CD4⁺水平低于未合并感染者(P<0.05),IL-4、IFN-γ水平均高于未合并感染者(P<0.05);COPD合并革兰氏阴性菌感染者CD4⁺CD25⁺水平低于未合并感染者(P<0.05),IL-10水平均高于未合并感染者(P<0.05);CD4⁺、IL-4、IL-10、IFN-γ均是预测COPD患者合并细菌感染的有效指标(P<0.05),其中IL-4和IFN-γ效能较高。结论 CD4⁺、CD4⁺CD25⁺Treg细胞及其相关细胞因子参与COPD发生发展和患者细菌感染,监测其水平变化有利于为临床诊治提供信息。

Objective To investigate the correlation between the expressions of negative regulatory cell CD4⁺CD25⁺T and its related cytokines in peripheral blood and bacterial infection of patients with chronic obstructive pulmonary disease (COPD). Methods Sixty-six COPD patients admitted between January 2018 and December 2019 were included as the research subjects, including 36 patients with acute exacerbation of COPD (AECOPD) and 30 patients with stable COPD. Another 30 healthy people undergoing physical examination during the same period were included in control group. The expression levels of CD4⁺CD25⁺ regulatory T cell and its related cytokines [interleukin-4 (IL-4), interleukin-10 (IL-10), interferon-γ (IFN-γ)] in the peripheral blood samples were detected among the included subjects. The relationship between levels of related indicators and presence or absence of bacterial infection in COPD and the efficacy of predicting infection were analyzed. Results The levels of CD4⁺, CD4⁺CD25⁺ and IFN-γ/IL-4 in patients with AECOPD and patients with stable COPD were lower than those in control group (P<0.05), while the levels of IL-4 and IL-10 were higher than those in control group (P<0.05). The IFN-γ level of AECOPD patients was higher than that of control group (P<0.05). The levels of CD4⁺ and CD4⁺CD25⁺of AECOPD patients were lower than those of stable COPD patients (P<0.05), while the levels of IL-4, IL-10 and IFN-γ were all higher than those of stable COPD patients (P<0.05). The levels of CD4⁺ and CD4⁺CD25⁺were negatively correlated with IL-4 and IFN-γ (P<0.05), and the CD4⁺level was negatively correlated with IL-10 (P<0.05). The CD4⁺ level in COPD patients with infection was lower than that in patients without infection (P<0.05), while the levels of IL-4 and IFN-γ were higher than those in patients without infection (P<0.05). The CD4⁺CD25⁺level of COPD patients with Gram-negative bacteria infection was lower than that of patients without infection (P<0.05), while the IL-10 level was higher than that of patients without infection (P<0.05). CD4⁺, IL-4, IL-10 and IFN-γ were effective indicators in predicting bacterial infection in COPD patients (P<0.05), and IL-4 and IFN-γ had higher efficacy. Conclusions CD4⁺, CD4⁺CD25⁺ T cell and related cytokines are involved in the occurrence and development of COPD and bacterial infection in patients. Monitoring changes of those levels is helpful to provide information for clinical diagnosis and treatment.