【作者】 林春鑫；

【导师】 夏宁邵；

【作者基本信息】 厦门大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 结核病是由结核分枝杆菌(mycobacterium tuberculosis,MTB)感染所致的以呼吸系统感染为主的慢性传染病,严重威胁着人类健康。目前结核病呈现出扩大蔓延的趋势。统计显示,全球1/3的人感染过结核分枝杆菌,但现有的用于诊断结核感染的方法都存在或多或少的缺陷,突出问题是灵敏度、特异性低下。因此需要一种新的诊断技术以祢补现有方法的不足。结核分枝杆菌感染人体后能激活机体免疫系统,产生针对结核分枝杆菌的效应性T淋巴细胞和记忆性T淋巴细胞,当这些特异性T淋巴细胞再次遇到结核分枝杆菌抗原时,则能被激活,分泌细胞因子(如IFN-γ)。据此,并参考已有的文献报道,本研究建立了一种新型的结核体外诊断试剂——全血结核IFN-γ体外释放试验(TB IFN-γrelease assay,TB-IGRA),包含有体外细胞培养系统和细胞因子定量系统,检测时间在24小时左右。经过初步临床验证,TB-IGRA的灵敏度为95.8%,特异性为96.3%。本试剂不仅对肺结核有较高的检出率,同时在肺外结核中的检出率达92.9%。在对病人接受治疗的前后TB-IGRA结果变化的研究中发现,IGRA检测值即刺激产生的IFN-γ浓度随着病人的康复而下降,阴转率53.8%,提示本试剂结果同病人的病程发展具有一定的关系,可作为提示病程的一个指标。在一次结核爆发的调查研究中发现,本试剂的结果同结核暴露程度正相关,与结核菌素皮肤试验(TST)相比,由于TST的检测特异性受卡介苗大量接种的影响而降低,易产生假阳性,而TB-IGRA能祢补其不足。同时还发现,本研究建立的TB-IGRA试剂和对照试剂QFT在结核无症状携带者中具有相同的检出能力。本研究成功建立了全血结核IFN-γ体外释放试验试剂盒,并验证了其相关参数已经符合使用要求。将本试剂盒应用于临床初步验证,发现在若干领域具备进一步深入研究的必要,将在后续研究中继续验证本试剂的可靠性及临床价值。更多还原

【Abstract】 Tuberculosis(TB) is caused by Mycobacterium tuberculosis(MTB) infection, which is a serious threat to human health,it could lead to chronic respiratory diseases. At present,tuberculosis shows a trend to expand.About 1/3 people all over the world have been infected with MTB,but the existing diagnostic methods are more or less defective,and their main problem is the low sensitivity and specivity.So we need a new TB diagnostic method to overcome the existing methods deficiencies.The immune system will be activated with mycobacterium tuberculosis infection. The body will generate specific effector T cells and memory T cells for MTB.T cell activation and cytokine secretion(such as IFN-γ) will be happened after the specific lymphocyte cells encountered with MTB.Based on this theory and also the references, this study established a new TB diagnostic test called "TB IFN-γrelease assay, TB-IGRA".TB-IGRA contains in vitro cell culture system and cytokine quantification system,with time-cosuming of about 24hrs.After clinical trials,it shows that the sensitivity of TB-IFN-γis 95.8%,and the specivity is 96.3%,which is better than former reagents.This reagent has a high sensitivity in not only tuberculosis but also extra-pulmonary tuberculosis(EPTB).The sensitivity in EPTB is 92.9%.This study also shows that there is a certain relationship between TB-IGRA results and the patient physical conditions.TB-IGRA results decreased when patients got healed,the negative conversion ratio is 53.8%,so TB-IGRA might be the indicator of the progression of the disease.A study on one TB outbreak incident shows that the results of this reagent is positive correlated with the exposure to TB.At the same time,the study shows that TB-IGRA has the same capacity as QFT to detect the carriers of tuberculosis.This study successfully established whole blood TB IFN-γrelease assay kit,and we have verified the relevant parameters have been met with our requirements.We found that some areas should be further studied when we used this kit for primary clinical validation,and follow-up study will be continued to verify the reliability and the clinical value of this reagent.更多还原