哮喘患者CD4+CD25+調節性T細胞比例與炎癥因子的相關性*

高　煒

(北京市仁和醫院， 北京　102600)

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哮喘患者CD4+CD25+調節性T細胞比例與炎癥因子的相關性*

高煒

(北京市仁和醫院， 北京102600)

[摘要]目的： 探討哮喘患者外周血CD4+CD25+調節性T細胞比例與血清中炎癥因子的相關性。方法： 110例哮喘患者均分為哮喘急性發作組和哮喘緩解組， 55例健康體檢者作為對照組；用流式細胞儀測定哮喘患者外周血中CD4+CD25+調節性T細胞的比例，酶聯免疫法(ELISA)檢測被檢者血清中白細胞介素18(IL-18)、IL-4及轉化生長因子β(TGF-β)含量；用Spearman統計方法分析哮喘患者外周血中CD4+CD25+調節性T細胞的比例與血清中IL-18、IL-4和TGF-β含量的相關性。結果： 與對照組比較，哮喘緩解組、哮喘急性發作組患者全血細胞中CD4+CD25+ T細胞比例降低，血清中IL-18、IL-4及TGF-β含量升高(P<0.05)；與哮喘緩解組比較，哮喘急性發作組外周血中CD4+CD25+ T細胞的比例降低而血清中IL-18、IL-4及TGF-β含量升高(P<0.05)；Spearman相關分析結果顯示，哮喘患者外周血CD4+CD25+ T細胞比例均與血清IL-18、IL-4和TGF-β含量呈顯著負相關關系(r=-0.712、-0.629、-0.593，P=0.006、0.008、0.005)。結論： 外周血CD4+CD25+ T細胞的比例與哮喘的發生和發展密切相關，其機制可能與IL-18、IL-4和TGF-β升高有關。

[關鍵詞]哮喘； 白細胞介素類； 轉化生長因子β； CD4+CD25+調節性T細胞； 因素分析,統計學

哮喘是一種與氣道高反應性密切相關的慢性炎癥疾病，調節性T細胞(regulatory T cells)分化異常與哮喘的發病機制中的炎癥細胞及炎癥介質有關[1]。尤其是CD4+CD25+T細胞以其獨特的作用方式和功能特征，在支氣管哮喘的發生發展中發揮著重要作用[2-4]。本研究通過檢測不同哮喘患者外周血CD4+CD25+T細胞的變化及其與炎癥因子水平的關系，探討CD4+CD25+T細胞在哮喘中的作用機制及其與炎癥反應的相關性。

1資料與方法

1.1一般資料

110例哮喘患者分為哮喘急性發作組和哮喘緩解組，每組55例。所有患者均符合中華醫學會呼吸病學分會制定的支氣管哮喘防治指南對哮喘的診斷標準及分級標準[5]，近1月內未使用過其它哮喘治療類的藥物。排除合并心腦血管疾病、慢性支氣管炎、支氣管擴張、肺結核等其他肺部疾病的患者，排除近1月內有呼吸道感染者，或近期口服或吸入糖皮質激素的患者。哮喘急性發作組男31例，女24例，年齡41～72歲，平均(53.2±8.3)歲；哮喘緩解組男34例，女21例，年齡39～76歲，平均(51.9±6.8)歲。本研究得到醫院倫理委員會的批準，全部受試者均知情同意。另選取同期門診健康體檢者55例作為對照組，男34例，女21例，年齡39～76歲，平均(51.9±6.8)歲。對照組均無各器官系統急慢性疾病及過敏性疾病史。

1.2方法

全部受檢者均于清晨采集空腹靜脈血 5 mL，其中2.5 mL 3 000 r/min離心3 min分離血清，置于-20 ℃保存，用于檢測白細胞介素18(IL-18)、IL-4及轉化生長因子-β(transforming growth factor-β，TGF-β)含量，采用酶聯免疫法(ELISA)檢測，試劑盒購自Biosource 公司；另2.5 mL血液抗凝后，采用流式細胞儀(Beckman-CoulterXL100)測定CD4+CD25+T細胞數，計算外周血中CD4+CD25+T細胞比例。

1.3統計學方法

2結果

2.1CD4+CD25+調節性T細胞比例

與對照組比較，哮喘急性發作組、哮喘緩解組患者外周血中CD4+CD25+T細胞比例降低，哮喘急性發作組最低，差異有統計學意義(P<0.05)。見表1。

表1　3組受檢者外周血中CD4+CD25+調節性T細胞比例

(1)與對照組比較，P<0.05；(2)與哮喘緩解組比較，P<0.05

2.2IL-18、IL-4及TGF-β含量

哮喘急性發作組和哮喘緩解組血清中IL-18、IL-4及TGF-β含量高于對照組，差異有統計學意義(P<0.05)；哮喘急性發作組的IL-18、IL-4和TGF-β含量高于哮喘緩解組，差異有統計學意義(P<0.05)。見表2。

2.3CD4+CD25+T 細胞比例與血清炎癥因子含量相關性分析

Spearman相關分析結果顯示，哮喘患者外周血CD4+CD25+T細胞比例均與哮喘患者血清IL-18、IL-4和TGF-β含量呈顯著負相關關系(r=-0.712、-0.629、-0.593，P=0.006、0.008、0.005)。

表2　3組受檢者血清IL-18、IL-4及TGF-β水平

(1)與對照組比較，P<0.05；(2)與哮喘緩解組比較，P<0.05

3討論

哮喘是一種由多種細胞及細胞因子參與的慢性變態反應性氣道炎癥疾病，患者可因炎癥反應導致可逆性氣流受限，氣道縮窄及氣道重塑。1995 年首次報道CD4+CD25+T細胞以來，近年來CD4+CD25+T細胞在哮喘機制中的作用逐漸引起業內學者的關注[6-7]。調節性T細胞可強烈抑制效應性T細胞，屬于可能抑制其它細胞功能的T細胞群體，CD4+CD25+T細胞可通過細胞毒T淋巴細胞抗原-4和糖皮質激素誘導的腫瘤壞死因子受體(GITR)與靶細胞相應受體的結合，從而抑制效應性T細胞的增殖，還可通過與樹突狀細胞等抗原提呈細胞作用來調節機體免疫[8-9]。近年來多項研究表明，炎癥狀態下多種細胞如T細胞、巨噬細胞等炎性細胞均能分泌IL-18，使其水平顯著升高，而升高的IL-18能刺激 NK 細胞和 T 細胞產生更多Th1型細胞因子和Th2型細胞因子，促進IL-4分泌增加，加重炎癥反應[10-11]。TGF-β對維持外周CD4+CD 25+T細胞的數量、功能至關重要，研究證實TGF-β能使CD4+CD25-T細胞轉變為具有調節功能的CD4+CD25+T細胞，減低Th1型和Th2型細胞因子的產生，在哮喘慢性氣道炎癥中發揮重要作用[12-13]。

本研究結果顯示哮喘急性發作組、哮喘緩解組患者全血細胞中CD4+CD25+T細胞比例低于對照組，且哮喘急性發作組最明顯(P<0.05)；推測CD4+CD25+調節性T細胞參與介導機體對過敏原耐受的形成過程，通過抑制氣道的嗜酸性粒細胞炎癥反應，控制哮喘惡化，哮喘患者外周血 CD4+CD25+T細胞比例降低是哮喘的發病機制之一。本研究還發現，哮喘急性發作組、哮喘緩解組患者血清IL-18、IL-4和TGF-β含量高于對照組，哮喘急性發作組最高(P<0.05)。提示哮喘患者處于緩解期時，雖無任何臨床癥狀，但支氣管仍存在持續炎癥狀態，因此致使體內血清炎癥因子的表達增加。此外，本研究將哮喘患者CD4+CD25+T細胞比例與患者外周血IL-18、IL-4和TGF-β含量進行相關性分析，結果發現哮喘患者外周血CD4+CD25+T細胞比例與患者血清IL-18、IL-4和TGF-β含量呈顯著負相關，提示隨著哮喘患者CD4+CD25+調節性T細胞比例降低，哮喘患者免疫抑制功能下降，減弱了對Th2細胞的抑制作用，使Th2型免疫反應增強，造成患者血清中IL-18、IL-4及TGF-β等細胞炎癥因子的生成增加，患者機體全身和局部免疫功能紊亂，加重了哮喘氣道炎癥癥狀[14-15]。

綜上所述， IL-18、IL-4和TGF-β炎性細胞因子參與哮喘的發病機制，且在炎癥發生時和調節性T細胞共同發揮抗炎致炎雙重作用，調控哮喘病情進展。

4參考文獻

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(2016-05-15收稿，2016-06-20修回)

中文編輯： 吳昌學； 英文編輯： 劉華

[中圖分類號]R562.25

[文獻標識碼]A

[文章編號]1000-2707(2016)07-0851-04

DOI:10.19367/j.cnki.1000-2707.2016.07.027

Correlation between the CD4+CD25+T Regulatory Cells Proportion and Serum Inflammatory Factors in Peripheral Blood of Asthmatic Patients

GAO Wei

(BeijingRenheHospital,Beijing102600,China)

[Abstract]Objective: To investigate the relationship between the CD4+ CD25+ T regulatory cells proportion and serum inflammatory factors in peripheral blood of asthmatic patients. Methods: 110 cases of patients with asthma were selected as the research subjects, and divided into asthma acute attack group (n=55) and asthma remission group(n=55). Another 55 healthy people were selected as control group. Enzyme linked immunosorbent assay (ELISA) was used to detect the content of IL-18, IL-4 and TGF-β, and flow cytometry was used to detect the proportion of CD4+ CD25+ T regulatory cells in peripheral venous blood. Spearman statistical method was adopted to analyze the correlation between the CD4+ CD25+ T regulatory cells proportion and serum inflammatory factors in peripheral blood of asthmatic patients. Results: Compared with control group, CD4+ CD25+ T regulatory cells proportion of blood cell in asthma acute attack group and asthma remission group was significantly decreased while the content of IL-18, IL-4 and TGF-β significantly was increased(P<0.05). Compared with asthma remission group, in asthma acute attack group the CD4+ CD25+ T regulatory cells proportion of blood cell was significantly decreased while the content of IL-18, IL-4 and TGF-β significantly was increased(P<0.05). The correlation analysis showed that the contents of IL-18, IL-4 and TGF-β in asthma patients were negatively correlated with the proportion of CD4+ CD25+ T regulatory cells (r=-0.712, -0.629, -0.593, P=0.006, 0.008, 0.005). Conclusions: The proportion of CD4+ CD25+ regulatory T cells is closely related to the occurrence and development of asthma, and its mechanism may be related to content increase of IL-18, IL-4 and TGF-β.

[Key words]asthma; interleukins; transforming growth factor β; CD4+CD25+ T regulatory cells; factors analysis, statistics

*網絡出版時間：2016-07-17網絡出版地址：http://www.cnki.net/kcms/detail/52.5012.R.20160717.1318.028.html