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五、 结核性脑膜炎的免疫学诊断
由于脑脊液含菌量少,导致涂片和培养阳性率低,免疫学检测是诊断结核性脑膜炎的重要方法之一。Patil等 [34]为了评价斑点杂交法检测结核抗体用于诊断结核性脑膜炎的可靠性,以40例结核性脑膜炎,68例非结核性脑膜炎(19例非传染性神经系统疾病,30例化脓性脑膜炎,19例病毒性脑膜炎)患者为研究对象,与ELISA法进行了对比观察。ELISA法:40例结核性脑膜炎患者中29例为阳性(72.5%);非结核性脑膜炎组中,3例化脓性脑膜炎为阳性(4.4%)。斑点杂交法:40例结核性脑膜炎患者中28例为阳性(70%);非结核性脑膜炎组中,2例化脓性脑膜炎为阳性(2.9%)。两种方法比较差异无显著性( P=0.50);作者认为,斑点杂交法和ELISA法检测结核抗体在统计学上无明显差异,而斑点杂交法的优点在于操作简单、耗时短、所需标本量小,尤其在实验室资源受限的发展中国家,可替代ELISA法用于结核性脑膜炎的快速诊断。Kashyap等 [35]提出了应用结核分枝杆菌Ag85复合物合成肽诊断结核分枝杆菌感染的方法。他们首先合成4种与结核分枝杆菌Ag85复合物有相同表位基因的多肽(7~10个氨基酸长度),而后采集入选病例的血清(肺结核55例,对照组63例)和脑脊液(结核性脑膜炎17例,对照组17例)标本,用ELISA法进行免疫学检测,在两个样本中对4种多肽的诊断价值进行评估。结果提示:脑脊液标本中,多肽1、2、3、4诊断结核性脑膜炎的敏感性分别为70.59%、64.71%、52.94%、52.94%,特异性分别为82.35%、88.24%、94.12%、100%;在血清标本中,4种多肽诊断肺结核的敏感性分别为85.45%、76.36%、85.45%、89.09%,特异性分别为84.13%、92.06%、93.64%、85.71%。由上可见,Ag85多肽 1、3、4对肺结核诊断有很高的阳性率,而1、2对结核性脑膜炎的诊断有很高的阳性率。作者提出,和完整抗原比较,结核分枝杆菌Ag85复合物多肽比较容易合成,以其为基础的ELISA法是早期诊断肺结核及肺外结核的快速、特异、有效、敏感的方法。
Song等 [36]为了评价结核分枝杆菌抗原ESAT-6对结核性脑膜炎的早期诊断价值,采用间接ELISA法,对100例脑脊液标本进行ESAT-6检测,其中结核性脑膜炎组50例(确诊病例10例,临床诊断病例40例),非结核性脑膜炎组(其他性质脑膜炎40例,健康志愿者10例)50例,结核性脑膜炎组病程均<2周。结果提示:脑脊液ESAT-6检测在结核性脑膜炎确诊病例、临床诊断病例和非结核性脑膜炎组的阳性率(可检测到的最小量为1ng/ml)分别为90%(9/10)、87.5%(35/40)和8%(4/50),其诊断结核性脑膜炎的敏感性为88%,特异性为92%;结核性脑膜炎组脑脊液ESAT-6平均含量为[(85.13±18.18)ng/ml)],明显高于非结核性脑膜炎组[(2.76±1.57)ng/ml]( P<0.001)。作者提出,脑脊液结核分枝杆菌抗原ESAT-6检测用于结核性脑膜炎早期诊断是可靠的。此外,研究还发现,结核性脑膜炎确诊病例ESAT-6水平明显高于临床诊断病例[(112.87±16.67)ng/ml vs (78.20±10.22)ng/ml, P<0.001]。并且结核性脑膜炎组中有24 例ESAT-6含量>70ng/ml,其中14例存在神经系统后遗症,而ESAT-6含量<70ng/ml者无神经系统后遗症。上述发现提示,重症结核性脑膜炎病例脑脊液ESAT-6含量较高,这一特点可能对预后评估有所帮助。
Rv2623抗原是一种主要的结核分枝杆菌休眠调节蛋白,Jain等 [37]观察了其在隐性结核性脑膜炎和活动性结核性脑膜炎患者脑脊液中的表达情况,探讨其是否能作为一个新的生物学标志物用于隐性结核性脑膜炎和活动性结核性脑膜炎的诊断。此研究纳入100个脑脊液样本,包括结核性脑膜炎31例、可疑隐性结核性脑膜炎22例和非结核性脑膜炎47例,采用ELISA法对Rv2623抗原进行检测评估。结果显示:结核性脑膜炎组和可疑隐性结核性脑膜炎组Rv2623水平分别为0.64±0.09和0.65±0.14,明显高于非结核性脑膜炎组(0.37±0.07)( P<0.05);但疑似隐性结核性脑膜炎及活动结核性脑膜炎组比较差异无显著性( P>0.05)。应用ROC曲线以≥0.54为诊断临界值,脑脊液Rv2623检测用于诊断活动性结核性脑膜炎和可疑隐性结核性脑膜炎的敏感性分别为90.32%(95%CI 74.22%~97.85%)和77.27%(95%CI 54.62%~92.09%),特异性均为100%(95%CI 92.38%~100%),阳性预测值分别为100%(95%CI 87.54%~100%)和100%(95%CI 80.33%~100%),阴性预测值分别为94%(95%CI 83.43%~98.68%)和90%(95%CI 78.96%~96.77%)。作者指出,初步研究表明,Rv2623抗原可能作为一种新的生物学标志物用于隐性结核性脑膜炎和活动性结核性脑膜炎的诊断,但这一推断尚需进行大样本的、与诊断金标准的对照研究来进一步证实。
血管内皮生长因子(VEGF)与脑水肿及脑梗死存在联系,但尚缺乏关于结核性脑膜炎患者VEGF水平与MRI变化之间关系的研究。Misra等 [38]对40例结核性脑膜炎患者进行了血清VEGF水平检测,并同健康对照组比较,探讨其与临床表现、实验室检查及MRI表现之间的关系。40例患者中34例存在MRI异常,表现为渗出物、脑积水、梗死及结核瘤;研究结果提示:结核性脑膜炎组血清VEGF水平[(100.7±110.6)pg/ml)]高于对照组[(60.6±20.3)pg/ml)]( P=0.06)。在病程短(<2个月)的患者[(127.5±152.4)pg/ml vs(76.5±40.9)pg/ml, P=0.17)]、MRI有梗死的患者[(131.4±150.7)pg/ml vs(73.0±41.4)pg/ml, P=0.10)]、发生矛盾反应的患者[(122.3±157.6)pg/ml vs(88.8±50.8)pg/ml, P=0.47)]中VEGF均有升高趋势。存在渗出物、结核瘤、脑积水及死亡病例(5例)与VEGF水平无明显关联。因此作者提出,病程短、有脑梗死及治疗后发生矛盾反应的结核性脑膜炎患者,血清VEGF水平轻微增高。但经统计学分析,尚无显著意义,应进一步进行大样本研究探讨脑脊液VEGF及其受体的变化情况。VEGF在结核性脑膜炎患者中可破坏血脑屏障而使病情加重,而 DNA-hsp65被称为结核感染的保护器,Zucchi等 [39]建立了一个中枢神经系统结核病的小鼠模型,并为小鼠接种DNA-hsp65疫苗,观察VEGF如何参与中枢神经系统结核病以及接种DNA-hsp65疫苗是否可以阻止VEGF生成及预防结核病。具体方法是向接种疫苗的小鼠和对照组(未接种疫苗)小鼠的小脑内注射牛分枝杆菌卡介苗,注射后4周牛分枝杆菌在小鼠体内播散,将脑组织用石蜡包埋,观察VEGF免疫组化表达情况。未接种疫苗组小鼠的脑实质(形成肉芽肿的小鼠)、蛛网膜下腔(形成脑膜炎小鼠)、血管壁、小脑和脑桥几种类型细胞的胞质中均可见高水平表达的VEGF;而接种疫苗组小鼠不易形成肉芽肿,VEGF水平较对照组低,尤其值得注意的是接种疫苗患脑膜炎(无脑实质损伤)的小鼠无VEGF表达。上述观察表明,VEGF参与了结核性脑膜炎的病理生理过程,而DNA-hsp65对结核性脑膜炎的进展有潜在的预防作用。同时,VEGF高水平表达这一特点可能对结核性脑膜炎的诊断有所帮助。
(胡族琼 尹洪云 赵云虹 刘一典 张青 闫世明 唐神结)
参考文献
1. Metcalfe JZ,Cattamanchi A,McCulloch CE. Test Variability of the QuantiFERON-TB Gold In-Tube Assay in Clinical Practice. Am J Respir Crit Care Med,2013,187(2):206-211.
2. Cheallaigh CN,Fitzgerald I,Grace J,et al. Interferon Gamma Release Assays for the Diagnosis of Latent TB Infection in HIV-Infected Individuals in a Low TB Burden Country. PLOS ONE,2013,8(1):e53330.
3. Zhang LF,Liu XQ,Zhang Y,et al. A prospective longitudinal study evaluating a T-cell-based assay for latent tuberculosis infection in health-care workers in a general hospital in Beijing . Chin Med J,2013,126(11):2039-2044.
4. Serrano-Escobedo CJ,Enciso-Moreno JA,Monárrez-Espino J. Performance of Tuberculin Skin Test Compared to QFT-IT to Detect Latent TB Among High-risk Contacts in Mexico. Arch Med Res,2013,44:242-248.
5. Khalil KF,Ambreen A,Butt T. Comparison of Sensitivity of QuantiFERONTB Gold Test and Tuberculin Skin Test in Active Pulmonary Tuberculosis. J Coll Physicians Surg Pak,2013,23(9):633-636.
6. Lodha R,Mukherjee A,Saini D,et al. Role of the QuantiFERON ®-TB Gold In-Tube test in the diagnosis of intrathoracic childhood tuberculosis. Int J Turberc Lung Dis,2013,17(11):1383-1388.
7. Jafari C,Ernst M,Kalsdorf B,et al. Comparison of molecular and immunological methods for the rapid diagnosis of smear-negative tuberculosis. Int J Turberc Lung Dis,2013,17(11):1459-1465.
8. Bua A,Molicotti P,Cannas S,et al. Tuberculin skin test and QuantiFERON in children. New Microbiol,2013,36(2):153-156.
9. Wassie L,Aseffa A,Abebe M,et al. Parasitic infection may be associated with discordant responses to QuantiFERON and tuberculin skin test in apparently healthy children and adolescents in a tuberculosis endemic setting,Ethiopia. BMC Infect Dis,2013,13:265. doi:10. 1186/1471-2334-13-265.
10. Blandinières A,de Lauzanne A,Guérin-El Khourouj V,et al. QuantiFERON to diagnose infection by Mycobacterium tuberculosis:Performance in infants and older children. J Infect,2013,67(5):391-398.
11. Hradsky O,Ohem J,Zarubova K,et al. Disease Activity is an Important Factor for Indeterminate Interferon-γ Release Assay Results in Children With Inflammatory Bowel Disease. J Pediatr Gastroenterol Nutr. 2014,58(3):320-324.
12. Mukherjee A,Saini S,Kabra SK,et al. Effect of micronutrient deficiency on QuantiFERON-TB Gold In-Tube test and tuberculin skin test in diagnosis of childhood intrathoracic tuberculosis. Eur J Clin Nutr,2014,68(1):38-42.
13. Schopfer K,Rieder HL,Bodmer T,et al. The sensitivity of an interferon-γ release assay in microbiologically confirmed pediatric tuberculosis. Eur J Pediatr,2014,173(3):331-336.
14. Mandalakas AM,van Wyk S,Kirchner HL,et al. Detecting tuberculosis infection in HIV-infected children:a study of diagnostic accuracy,confounding and interaction. Pediatr Infect Dis J,2013,32(3):e111-118.
15. Ling DI,Nicol MP,Pai M,et al. Incremental value of T-SPOT. TB for diagnosis of active pulmonary tuberculosis in children in a high-burden setting:a multivariable analysis. Thorax,2013,68(9):860-866.
16. Schepers K,Mouchet F,Dirix V,et al. Long-incubation time-interferongamma release assays in response to PPD-,ESAT-6-and/or CFP-10 for the diagnosis of Mycobacterium tuberculosis infectionin children. Clin Vaccine Immunol,2014,21(2):111-118.
17. Chegou NN,Detjen AK,Thiart L,et al. Utility of host markers detected in Quantiferon supernatants for the diagnosis of tuberculosis in children in a high-burden setting. PLoS One,2013,8(5):e64226.
18. Dhanasekaran S,Jenum S,Stavrum R,et al. Identification of biomarkers for Mycobacterium tuberculosis infection and disease in BCG-vaccinated young children in Southern India. Genes Immun,2013,14(6):356-364.
19. 田建岭,刘晓灵,孙琳,等. 结核分枝杆菌特异性效应T细胞斑点数鉴别儿童活动性结核病与潜伏结核感染的价值. 中国循证儿科杂志,2013,8(4):272-276.
20. 李瑞,刘继贤,包丽丽,等. 检测分泌γ-干扰素T细胞对诊断儿童结核的意义. 中国医学创新,2013,10(17):80-83.
21. 孟珊珊,张乐乐,张海邻,等. 酶联免疫斑点技术对儿童结核病诊断的应用价值. 医学研究杂志,2013,42(10):151-154.
22. 王立红,付秀华,张桂芝,等. 结核感染T 细胞斑点试验在结核病诊断中的应用价值. 中国防痨杂志,2013,35(12):992-996.
23. Hur YG,Gorak-Stolinska P,Ben-Smith A. Combination of Cytokine Responses Indicative of Latent TB and Active TB in Malawian Adults. PLOS ONE,2013,8(11):e79742.
24. Chegou NN,Heyckendorf J,Walzl G. Beyond the IFN-γ horizon:Biomarkers for immunodiagnosis of infection with M. tuberculosis. ERJ Express,Published on December 5,2013 as doi:10. 1183/09031936. 00151413.
25. Pollock KM,Whitworth HS,Montamat-Sicotte DJ. T-cell immunophenotyping distinguishes active from latent tuberculosis. J Infect Dis,2013,208(6):952-968.
26. Yamashita Y,Hoshino Y,Oka M,et al. Multicolor flow cytometric analyses of CD4+ T cell responses to Mycobacterium tuberculosis-related latent antigens. Jpn J Infect Dis,2013,66(3):207-215.
27. Marín ND,París SC,Rojas M,et al. Functional profile of CD4+ and CD8+ T cells in latently infected individuals and patients with active TB. Tuberculosis(Edinb),2013,93(2):155-66.
28. 王心静,曹志红,杨秉芬,等. 结核分枝杆菌特异性抗原反应性因子对活动性肺结核的鉴别诊断意义. 免疫学杂志,2013,9:822-825.
29. Singh SB,Biswas D,Rawat J. Ethnicity-tailored novel set of ESAT-6 peptides for differentiating active and latent tuberculosis. Tuberculosis,2013,93:618-624.
30. Ashenafi S,Aderaye G,Zewdie M. BCG-specific IgG-secreting peripheral plasmablasts as a potential biomarker of active tuberculosis in HIV negative and HIV positive patients. Thorax,2013,68:269-276.
31. Hwang WH,Lee WK,Ryoo SW,et al. Expression,purification and improved antigenicity of the Mycobacterium tuberculosis PstS1 antigen for serodiagnosis. Protein Expression and Purification,2014,95:77-83.
32. Legesse M,Ameni G,Medhin G,et al. IgA Response to ESAT-6/CFP-10 and Rv2031 Antigens Varies in Patients With Culture-Confirmed Pulmonary Tuberculosis,Healthy Mycobacterium tuberculosis Infected and Non-Infected Individuals in a Tuberculosis Endemic Setting,Ethiopia. Scand J Immunol,2013,78:266-274.
33. 闫国蕊,王勇鸣,杨萍,等. 结核抗体联合检测对结核病诊断价值分析.中国防痨杂志,2013,35(4):286-287.
34. Patil S A,Kavitha A K,Madhusudan A P,et al. Comparative evaluation of ELISA and dot-blot for the diagnosis of tuberculous meningitis. J Immunoassay Immunochem,2013,34(4):404-413.
35. Kashyap R S,Shekhawat S D,Nayak A R,et al. Diagnosis of tuberculosis infection based on synthetic peptides from Mycobacterium tuberculosis antigen 85 complex. Clin Neurol Neurosurg,2013,115(6):678-683.
36. Song F,Sun X,Wang X,et al. Early diagnosis of tuberculous meningitis by an indirect ELISA protocol based on the detection of the antigen ESAT-6 in cerebrospinal fluid. Ir J Med Sci,2014,183(1):85-88.
37. Jain R K,Nayak A R,Husain A A,et al. Mycobacterial dormancy regulon protein rv2623 as a novel biomarker for the diagnosis of latent and active tuberculous meningitis. Dis Markers,2013,35(5):311-316.
38. Misra U K,Kalita J,Singh A P,et al. Vascular endothelial growth factor in tuberculous meningitis. Int J Neurosci,2013,123(2):128-132.
39. Zucchi F C,Tsanaclis A M,Moura-Dias Q J,et al. Modulation of angiogenic factor VEGF by DNA-hsp65 vaccination in a murine CNS tuberculosis model. Tuberculosis(Edinb),2013,93(3):373-380.