咳嗽变异型哮喘患者T细胞亚群水平变化与小气道功能的关系

目的：探讨咳嗽变异型哮喘（CVA）患者外周血T细胞亚群数量与小气道功能变化的相关性及其临床意义。方法：用流式细胞仪测定分析32例CVA患者（CVA组）及24例健康人（正常组）外周血T细胞亚群（CD2^＋T、CD4^＋T、CD4^＋T、CD4／CD8的比值）水平的变化。并测定反映大气道和小气道（FVC、FEV1和FEF25％-75％、FEF75％-85％）功能的指标。结果：①CVA组患者外周血CD4^＋T及CD4／CD8比值显著高于正常组（P〈0．05，P〈0．01）；CD8^＋T显著性低于正常组（P〈0．01）；CD3^＋T与正常组差异无显著性意义。②CVA组FEF25％-75％及FEF75%-85％值明显低于正常组（P〈0．05）。③FEF25%-75%、FEF75%-85％与CD^4＋T水平皆呈负相关（前者r=-0．462，P=0．021；后者r=-0．461，P=0．019），与CD4／CD8比值也呈负相关（前者r=-0，529，P=0．009，后者r=-0．501，P=0．013）；FVC、FEV1与外周血CD3^＋T、CD4^＋T、CD8^＋T及CD4／CD8比值无相关性。结论：FEF25％-75%、FEF75％-85%对CVA患者的早期诊断有重要意义；CVA患者FEF25%-75%、FEF75％-85％与CD4^＋T、CD4／CD8的比值有负相关性，说明患者体内细胞免疫功能异常，在哮喘变应性气道炎症中起重要作用。可能是导致CVA患者小气道功能进一步减退的原因。早期诊断、治疗CVA，可防止典型哮喘发作，降低入院率及死亡率。

Relationship between the Levels of T Lymphocyte Subsets and the Small Airway Ventilatory Function in Cough Variant Asthma Patients

Objective: To investigate the relationship between the changes of T lymphocyte subsets in peripheral blood and small airway ventilatory function(FEF_(25%-75%) and FEF_(75%-85%)) in cough variant asthma(CVA) patients and its clinical significance.Methods: Flow cytomerty was used to analyze the lymphocyte subsets(CD_4~+,CD_8~+) in the peripheral blood from 32 cough variant asthma patients and 24 healthy subjects.Indices of FVC,FEV_1,FEF_(25%-75%) and FEF_(75%-85%) were recorded.Results:(1) The percentages of CD_4~+ T lymphocytes and CD_4/CD_8 in CVA patients were both significantly higher in the CVA group than in the normal control group(P<0.05,P<0.01);The percentage of CD_8~+ T lymphocyte was significantly lower in the CVA group than in the normal control group(P<0.01);There were no significant differences in the percentage of CD_3~+ T lymphocyte between CVA patients and the normal control group;(2) The indices of FEF_(25%-75%) and FEF_(75%-85%) were both significantly lower in the CAV group than in normal control group(P<0.01);(3) The level of FEF_(25%-75%) was negatively correlated with CD_4~+ T(r=-0.462,P=0.021) and CD_4/CD_8 ratio(r=-0.529,P=0.009);The levels of FEF_(75%-85%) were negatively correlated with CD_4~+ T(r=-0.461,P=0.019) and CD_4/CD_8 ratio(r=-0.501,P=0.013);The values of FVC and FEV_1 were not related to the percentages of CD_3~+ T,CD_4~+ T,CD_8~+ T and CD_4/CD_8.Conclusion:(1) Changes in the level of T lymphocyte subsets in peripheral blood may play an important role in the pathogenesis of CVA.(2) The increase of CD_4~+ T lymphocytes and the imbalance in the ratio of CD_4/CD_8 may result in the disturbance of immune in CVA patients and may lead to further deterioration of small airway ventilatory function.Therefore,atypical asthma can be prevented from attacking if CVA can be diagnosed and treated early.This can lead to the decrease of the admission rate and mortality rate caused by asthma.