發(fā)布時(shí)間：2018-07-02 09:27

  本文選題：免疫性血小板減少癥 + T細(xì)胞亞群��； 參考：《蘇州大學(xué)》2013年博士論文

【摘要】：免疫性血小板減少性紫癜（immune thrombocytopenia，ITP）是一種以血小板免疫性破壞為特征的自身免疫性疾病。臨床上分為慢性ITP與急性ITP，慢性ITP多發(fā)病于20~50歲之間，女性發(fā)病率較男性高2~3倍，絕大多數(shù)慢性ITP患者缺乏臨床表現(xiàn)或明確的病因。急性ITP是兒童比較常見的出血性疾病，發(fā)病年齡以2～5歲之間為多，病程一般4～6周，多數(shù)患兒病情可自行緩解，痊愈后很少?gòu)?fù)發(fā)，多在病毒感染或預(yù)防接種后發(fā)生，成人少見，無性別差異，通常在冬春季節(jié)、病毒感染高峰期發(fā)病較多。根據(jù)臨床經(jīng)驗(yàn)，急性ITP大多可自然緩解，而慢性ITP起病隱匿，病因復(fù)雜。越來越多的證據(jù)表明，ITP患者除體液免疫功能紊亂，產(chǎn)生自身抗血小板抗體外，還存在T細(xì)胞亞群的失衡，如Th1/Th2平衡失調(diào)，并以Th1異常表達(dá)占優(yōu)勢(shì)，另外有研究表明，Treg及Th17細(xì)胞數(shù)目均發(fā)生異常。 目前臨床對(duì)于ITP的治療主要是通過三種途徑來達(dá)到血小板數(shù)目的增加：（1）通過抑制血小板的清除，比如脾切除術(shù)；（2）通過抑制或者糾正異常的免疫反應(yīng)，比如皮質(zhì)甾醇類藥物或者rituximab；（3）通過增加血小板的生成，比如TPO-RAs。但是對(duì)于部分慢性ITP患者的治療效果卻不顯著，臨床比較棘手。 有報(bào)道指出，短程大劑量地塞米松沖擊療法對(duì)慢性ITP患者有較好的治療效果，但是機(jī)制不明。本研究試圖研究地塞米松對(duì)ITP患者的治療效果并闡明其作用機(jī)制。本文首先對(duì)ITP患兒外周血中的T細(xì)胞亞群，包括Th1、Th2、Treg及Th17細(xì)胞進(jìn)行流式分析，并對(duì)IL-2、IFN-γ、IL-4、IL-10、TGFβ及IL-17等細(xì)胞因子進(jìn)行ELISA測(cè)定，對(duì)T-bet、GATA-3、Foxp3及RORγt進(jìn)行實(shí)時(shí)定量PCR分析，初步探討ITP患兒中T細(xì)胞亞群的改變。再進(jìn)一步對(duì)慢性ITP患者進(jìn)行短程大劑量地塞米松沖擊療法，觀察其治療效果并闡述其作用機(jī)制。 我們對(duì)30例正常對(duì)照和30例ITP患兒進(jìn)行Th1、Th2、Treg、Th17的流式分析，結(jié)果表明，Th1細(xì)胞在正常對(duì)照與ITP患兒中沒有顯著變化，而Th2細(xì)胞在ITP患兒中的表達(dá)顯著降低，ITP患兒中Treg細(xì)胞數(shù)目減少而Th17細(xì)胞數(shù)量增加。用ELISA方法分別檢測(cè)各細(xì)胞因子含量，結(jié)果發(fā)現(xiàn)，Th1的細(xì)胞因子（IL-2及IFN-γ）在ITP患兒外周血中含量明顯升高，而Th2的細(xì)胞因子（IL-4和IL-10）含量明顯降低，TGFβ及IL-17的表達(dá)與Treg及Th17細(xì)胞含量結(jié)果一致，分別為降低和升高。 Realtime PCR結(jié)果顯示ITP患者外周血PBMC中T-bet的表達(dá)沒有顯著變化，但是GATA-3及Foxp3的表達(dá)在ITP患者中顯著降低，而RORγt的表達(dá)明顯升高。 我們對(duì)10名ITP患者進(jìn)行短程大劑量地塞米松沖擊治療，結(jié)果表明70%的患者在治療后血小板數(shù)量明顯增加，可達(dá)到正常水平。我們對(duì)T細(xì)胞亞群及轉(zhuǎn)錄因子進(jìn)行了分析，，結(jié)果表明，地塞米松治療的患者外周血Th2細(xì)胞及Treg細(xì)胞較未治療組有明顯的升高，Th17細(xì)胞有顯著的降低，同時(shí)我們發(fā)現(xiàn)轉(zhuǎn)錄因子表達(dá)改變趨勢(shì)與相關(guān)T細(xì)胞亞群相同。為了進(jìn)一步揭示用地塞米松糾正T細(xì)胞亞群失衡來治療ITP的機(jī)制，我們純化分離正常的T細(xì)胞，地塞米松體外處理。結(jié)果表明地塞米松可以抑制RORγt的表達(dá)，但是促進(jìn)GATA-3及Foxp3的表達(dá)。這些結(jié)果表明地塞米松是通過調(diào)節(jié)轉(zhuǎn)錄因子的表達(dá)水平從而影響T細(xì)胞亞群的分化來糾正ITP患者中T細(xì)胞亞群異常的狀態(tài)，從而達(dá)到治療ITP的目的。 綜上所述，我們首次對(duì)兒童ITP的T細(xì)胞亞群的含量、細(xì)胞因子及轉(zhuǎn)錄因子的表達(dá)進(jìn)行了分析，對(duì)異常T細(xì)胞亞群參與ITP的發(fā)病提供了更多的證據(jù)，并對(duì)大劑量地塞米松治療ITP患者的機(jī)制進(jìn)行了初步探討，這些研究結(jié)果為揭示ITP的發(fā)病機(jī)制并為治療ITP提供了重要信息。
[Abstract]:Immune thrombocytopenia (ITP) is a autoimmune disease characterized by immune destruction of platelets. It is divided into chronic ITP and acute ITP, and chronic ITP is frequently occurring between 20~50 years, the incidence of women is higher than that of men, and the majority of chronic ITP patients lack clinical manifestation or clear disease. Acute ITP is the most common hemorrhagic disease in children. The age of onset is more than 2~5 years old, and the course of disease is generally 4~6 weeks. Most of the sick children can be relieved by themselves. They seldom relapse after recovery. Most of them occur after virus infection or inoculation. Adults are rare and have no sex differences. Usually, there are more diseases in the peak period of the virus infection in winter and spring. According to clinical experience, most of the acute ITP can be naturally remission, and the chronic ITP disease is concealed and the cause is complex. More and more evidence shows that there is an imbalance of T cell subsets in ITP patients except for the disturbance of the humoral immune function and the production of their own anti platelet antibodies, such as the imbalance of Th1/Th2 and the abnormal expression of Th1, and the other studies have shown that Treg and The number of Th17 cells was abnormal.
The current clinical treatment of ITP is mainly through three ways to increase the number of platelets: (1) by inhibiting the clearance of platelets, such as splenectomy; (2) by inhibiting or correcting abnormal immune responses, such as steroid drugs or rituximab; (3) by increasing the formation of platelets, such as TPO-RAs., In some chronic ITP patients, the treatment effect is not significant.
It is reported that short range and large dose of dexamethasone has better therapeutic effects on chronic ITP patients, but the mechanism is unclear. This study tried to study the therapeutic effect of dexamethasone on ITP patients and elucidate the mechanism of its action. First, the flow formula of T cell subsets in peripheral blood of children with ITP, including Th1, Th2, Treg and Th17 cells was carried out. Analysis and ELISA determination of cytokines such as IL-2, IFN- gamma, IL-4, IL-10, TGF beta and IL-17. The changes of T-bet, GATA-3, Foxp3 and ROR T were analyzed in real time. Use the mechanism.
We performed a flow analysis of Th1, Th2, Treg and Th17 in 30 normal controls and 30 children with ITP. The results showed that there was no significant change in Th1 cells in normal controls and children with ITP, but the expression of Th2 cells in ITP decreased significantly. The number of Treg cells in ITP children decreased and the number of Th17 cells increased. The results showed that the cytokine (IL-2 and IFN- gamma) of Th1 increased significantly in the peripheral blood of children with ITP, while the content of the cytokines (IL-4 and IL-10) of Th2 decreased obviously. The expression of TGF beta and IL-17 was in accordance with the results of Treg and Th17 cells, which were decreased and increased respectively. There was no significant change in the expression of GATA-3 and Foxp3, but the expression of ROR and t increased significantly in ITP patients.
10 ITP patients were treated with short range and large dose of dexamethasone. The results showed that the number of platelets increased significantly in 70% of the patients and reached the normal level. We analyzed the T cell subsets and transcription factors. The results showed that the peripheral blood Th2 cells and Treg cells in the patients with dexamethasone were compared with those in the untreated group. In order to further reveal the mechanism of using dexamethasone to correct the T cell subpopulation imbalance in the treatment of ITP, we purify and separate normal T cells, and deimethasone in vitro. The results show that dexamethasone can inhibit the expression of Th17 cells. The expression of ROR gamma t contributes to the expression of GATA-3 and Foxp3. These results suggest that dexamethasone regulates the differentiation of T cell subsets by regulating the expression level of transcription factors to correct the abnormal state of T cell subsets in ITP patients, thus achieving the purpose of treating ITP.
To sum up, we first analyzed the expression of T cell subsets, cytokines and transcription factors in children's ITP, and provided more evidence for the involvement of abnormal T cell subsets in the pathogenesis of ITP, and the mechanism of the treatment of ITP patients with large dose of dexamethasone was preliminarily discussed in order to reveal the pathogenesis of ITP. And it provides important information for the treatment of ITP.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：R725.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 劉家華;徐軍發(fā);鐘明;周君純;陳小芳;;CD_4~+CD_(25)~+調(diào)節(jié)性T細(xì)胞在免疫性血小板減少性紫癜中的調(diào)節(jié)作用[J];臨床內(nèi)科雜志;2006年06期

2 錢莘,施明,王福生;流式細(xì)胞術(shù)檢測(cè)細(xì)胞內(nèi)細(xì)胞因子的研究進(jìn)展[J];細(xì)胞與分子免疫學(xué)雜志;2005年S1期

3 楊默,李桂霞;調(diào)控巨核系造血的細(xì)胞因子和轉(zhuǎn)錄因子(英文)[J];中國(guó)實(shí)驗(yàn)血液學(xué)雜志;2002年06期

4 王婷婷;趙輝;任賀;郭建海;徐茂強(qiáng);楊仁池;韓忠朝;;慢性特發(fā)性血小板減少性紫癜患者Ⅰ類和Ⅱ類T細(xì)胞特點(diǎn)的研究[J];中華醫(yī)學(xué)雜志;2006年10期

本文編號(hào)：2089680