非结核分枝杆菌肺病血清中细胞因子的检测及临床意义

目的研究血清白介素1(IL-1)、白介素2受体(IL-2R)、白介素6(IL-6)、白介素8(IL-8)、白介素10(IL-10)、肿瘤坏死因子α(TNF-α)和降钙素原(PCT)的检测在非结核分枝杆菌肺病患者的临床意义。方法采用酶联免疫方法(ELISA)检测11例非结核分枝杆菌肺病患者和14例对照组血清中IL-1、IL-2R、IL-6、IL-8、IL-10、TNF-α和PCT的水平变化。结果与对照组相比较,非结核分枝杆菌肺病组血清中TNF-α的含量明显升高(P0.05),而IL-1 IL-2R、IL-6、IL-8、IL-10和PCT等五个细胞因子的含量无明显变化(P0.05)。进一步分析结果显示,非结核分枝杆菌肺病组血清中TNF-α等六个细胞因子的含量变化与有否空洞无关(P0.05)。结论血清TNF-α在非结核分枝杆菌肺病患者血清中明显升高,可作为非结核分枝杆菌肺病感染诊断的辅助指标。     

蛋白电泳技术在结核性和肿瘤性胸腔积液鉴别诊断中的应用

应用生化分析仪和电泳仪分别对36例结核性积液患者(结核组)和44例肿瘤性胸腔积液患者(肿瘤组)行积液总蛋白测定和蛋白电泳分析.结果 结核组总蛋白、α1球蛋白、α2球蛋白均高于肿瘤组(P均<0.05),α2球蛋白与白蛋白比值明显低于肿瘤组(P<0.01).提示蛋白电泳分析有助于鉴别结核性与肿瘤性胸腔积液.     

肿瘤坏死因子-α拮抗剂引发结核二例分析并文献复习

目的 提高临床医生对肿瘤坏死因子(TNF)-α州拈抗剂治疗引发结核的认识.方法 报道2例类风湿关节炎(RA)患者经TNF-α拮抗剂治疗后发生结核病的临床情况,并复习近年国内外相关文献.结果 病例1在3个月内接受4次英夫利昔3 ms/ks静脉注射治疗后出现右锁骨上淋巴结结核,手术切除及四联抗结核治疗后痊愈.病例2接受依那西普25 mg皮下注射2次/周治疗1.5个月后发生肺结核瘤,手术切除后好转.文献复习显示TNF-α拮抗剂治疗可增加结核的发病率,英夫利昔的致结核作用强于依那西普,发生结核的患者多为老年人,肺外结核及播散性结核的发生率较高.结论 TNF-α拮抗剂治疗可增加结核的发病率,治疗前结核筛查、治疗期间及治疗后监测结核的发生很有必要.     

肿瘤坏死因子-α拮抗剂可抑制γδT淋巴细胞的免疫反应能力

肿瘤坏死因子(TNF)-α拮抗剂可增加患者发生感染(包括结核感染)的危险,而γδT淋巴细胞能识别来自分枝杆菌的非多肽抗原,在清除结核分枝杆菌感染的免疫反应中发挥重要作用.     

胸液α2-球蛋白与白蛋白比值在胸腔积液鉴别诊断中的价值

目的探讨α2球蛋白对结核性和癌性胸腔积液的鉴别诊断价值。方法分别对94例胸腔积液患者的胸液(结核性积液43例,癌性积液51例)进行蛋白电泳分析,检测白蛋白和α2球蛋白,计算α2-球蛋白与白蛋白比值。结果结核组α2球蛋白高于癌性组,差异有显著性(P<0.05);结核组α2-球蛋白与白蛋白比值低于恶性组,差异具有高度显著性(P<0.01)。结论胸腔积液α2球蛋白及α2-球蛋白与白蛋白比值检测有助于结核性与癌性胸腔积液的鉴别诊断。     

肺结核患者抗原特异性IFN-γ+ TNF-α+T细胞的检测分析

目的 研究肺结核患者与健康对照外周血T淋巴细胞中γ干扰素(IFN-γ)和肿瘤坏死因子α(TNF-α)的表达情况,初步探讨多功能性T细胞在结核发病中的作用.方法 分离外周血单个核细胞(PBMCs),与特异性结核抗原共培养后,用流式细胞仪检测外周血CD8+、CD4+T细胞以及CD3-CD8+细胞中抗原特异性IFN-γ和TNF-α的表达情况.通过非参数检验比较患者与PPD阳性健康对照者之间的表达差异.结果 根据细胞因子分泌的类型将每群细胞分成3个亚群,分别为两个单阳性细胞亚群(IFN-γ+ TNF-α-或IFN-γ-TNF-α+)和一个双阳性细胞亚群(IFN-γ+ TNF-α+)即多功能性细胞亚群.经统计学分析,肺结核患者三群细胞中抗原特异性多功能性细胞的比例均高于PPD阳性健康对照者(P=0.001,0.001和0.014),且对照组该亚群的比例大部分均在结核病患者均值以下.结论 多功能性T细胞很可能在结核的疾病进展过程中发挥重要作用.     

结核性气道狭窄中SIRT1对气管成纤维细胞增殖速度及分化的影响研究

目的观察沉默信息调节因子1(silent information regulator 1,SIRT1)在结核性气道狭窄气道增生肉芽组织中的表达及对气管成纤维细胞增殖速度与分化的影响。方法免疫组化染色检测气道增生肉芽组织与正常组织中SIRT1与肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)表达水平。CCK-8法和流式细胞术分别检测细胞增殖活性与周期分布,免疫荧光染色检测α平滑肌肌动蛋白(α-Smooth muscle actin,α-SMA)表达,蛋白质印迹法(Western blot)检测增殖细胞核抗原(Proliferating Cell Nuclear Antigen, PCNA)、α-SMA、Ⅰ型胶原蛋白(Collagen I,CoL-Ⅰ)、Ⅲ型胶原蛋白(CollagenⅢ,CoL-Ⅲ)蛋白表达水平,qRT-PCR检测CoL-Ⅰ、CoL-ⅢmRNA表达水平。结果结核性气道狭窄组中SIRT1与TNF-α阳性表达率较正常对照组升高(P<0.05)。与TGF-β1组比较,siRNA-SIRT1+TGF-β1组气管成纤维细胞增殖水平下降(P<0.05),G0/G1期细胞比例减少而S期细胞比例增加(P<0.05),α-SMA阳性染色减弱,PCNA、TNF-α、CoL-Ⅰ、CoL-Ⅲ蛋白表达均下降(P<0.05), CoL-Ⅰ、CoL-ⅢmRNA表达也下降(P<0.05)。结论 SIRT1在结核性气道狭窄患者的气道增生肉芽组织中表达增加,沉默SIRT1可抑制TGF-β1诱导的成纤维细胞的增殖速度与分化,并阻滞细胞周期。     

血清肿瘤坏死因子-α与免疫球蛋白E在肺结核感染患者中的表达及临床意义

目的探讨血清肿瘤坏死因子(TNF)-α与免疫球蛋白(Ig)E在肺结核感染患者中的表达及临床意义。方法选择2012年12月至2013年12月在该市传染病院接受治疗的358例肺结核感染患者作为观察组,对照组为该院同期376例健康体检者,对比分析两组的血清TNF-α和Ig E水平。结果观察组TNF-α和Ig E水平均显著高于对照组(t=1.026,0.968,P0.05),两者含量与痰结核分枝杆菌数量呈正相关(r=0.892,P0.05),继发性肺结核及结核性胸膜炎的TNF-α和Ig E水平均显著高于原发性肺结核和血行播散性肺结核(t=1.065,1.952,P0.05);TNF-α和Ig E也呈正相关(r=0.892,P0.05);治疗后,不同类型耐药者TNF-α和Ig E水平均有所下降,但其中耐多药结核者较治疗前下降不显著(t=0.648,P0.05),其余患者治疗前后差别均有统计学意义(t=8.497,6.258,5.346,P0.05)。结论 TNF-α和Ig E水平在肺结核感染患者病情严重程度的判定方面具有重要价值,具有临床应用价值。     

肿瘤坏死因子-α拮抗剂可降低巨噬细胞对结核分枝杆菌的免疫反应能力

爱尔兰学者Harris等研究显示,自身免疫性疾病患者在应用肿瘤坏死因子(TNF)-α拮抗剂治疗后,具体内巨噬细胞对结核分枝杆菌的免疫反应能力降低(J Infect Dis,2008,198:1842-1850).     

肺结核患者外周血sIL-2R、IL-6、IL-8、IL-10及TNF-α的检测意义

目的分析未抗痨治疗的结核患者及已经有效治疗的患者s IL-2R、IL-6、IL-8、IL-10及TNF-α表达的差异,以探讨上述指标的变化及意义。方法采用免疫化学发光法检测未抗结核治疗患者(A组)、抗结核治疗有效患者(B组)及健康组(C组)上述指标的表达水平,并比较各组差异。结果 A组C组相比较,均明显升高(P0.01)。B组s IL-2R和IL-6的含量较A组明显下降,分别为(509.41±96.52)U/ml vs(1207.09±105.33)U/ml和(8.91±3.22)pg/ml vs(37.84±15.46)pg/ml(P0.01);IL-8和TNF-α在B组中的含量较A组明显下降,分别为(12.78±3.69)pg/ml vs(23.82±5.67)pg/ml和(14.33±6.82)pg/ml vs(32.41±11.66)pg/ml(P0.05);而IL-10水平未发生明显变化。结论肺结核病患者s IL-2R、IL-6、IL-8、TNF-α水平明显增加,抗结核治疗后上述因子水平明显降低,初步提示s IL-2R、IL-6、IL-8、TNF-α表达水平与结核活动程度相关,有望进一步作为评价肺结核活动程度的指标。     

Interferon-gamma release assays are a better tuberculosis screening test for hemodialysis patients: A study and review of the literature

Diagnosing latent tuberculosis (TB) infection (LTBI) in dialysis patients is complicated by poor response to tuberculin skin testing (TST), but the role of interferon-gamma release assays (IGRAs) in the dialysis population remains uncertain. Seventy-nine patients were recruited to compare conventional diagnosis (CD) with the results of two IGRA tests in a dialysis unit. Combining TST, chest x-ray and screening questionnaire results (ie, CD) identified 24 patients as possible LTBI. IGRA testing identified 22 (QuantiFERON Gold IT, Cellestis, USA) and 23 (T-spot.TB, Oxford Immunotec, United Kingdom) LTBI patients. IGRA and CD correlated moderately (κ=0.59). IGRA results correlated with history of TB, TB contact and birth in an endemic country. TST was not helpful in identifying LTBI patients in this population. The tendency for IGRAs to correlate with risk factors for TB, active TB infection and history of TB argues for their superiority over TST in dialysis patients. There was no superiority of one IGRA test over another.     

Interferon-gamma release assays and TB screening in high-income countries: a cost-effectiveness analysis.

OBJECTIVE: Interferon-gamma release assays (IGRA) are now available alternatives to tuberculin skin testing (TST) for detection of latent tuberculosis infection (LTBI). We compared the cost-effectiveness of TST and IGRA in different populations and clinical situations, and with variation of a number of parameters. METHODS: Markov modelling was used to compare expected TB cases and costs over 20 years following screening for TB with different strategies among hypothetical cohorts of foreign-born entrants to Canada, or contacts of TB cases. The less expensive commercial IGRA, Quanti-FERON-TB Gold (QFT), was examined. Model inputs were derived from published literature. RESULTS: For entering immigrants, screening with chest radiograph (CXR) would be the most and QFT the least cost-effective. Sequential screening with TST then QFT was more cost-effective than QFT alone in all scenarios, and more cost-effective than TST alone in selected subgroups. Among close and casual contacts, screening with TST or QFT would be cost saving; savings with TST would be greater than with QFT, except in contacts who were bacille Calmette-Guérin (BCG) vaccinated after infancy. CONCLUSIONS: Screening for LTBI, with TST or QFT, is cost-effective only if the risk of disease is high. The most cost-effective use of QFT is to test TST-positive persons.     

Results of a tuberculosis-specific IFN-gamma assay in children at high risk for tuberculosis infection.

The specificity of the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI) is adversely affected by bacille Calmette-Guérin (BCG) vaccination and infection with non-tuberculous mycobacteria. Interferon-gamma release assays (IGRAs) using TB-specific antigens promise higher specificity. We compared a new IGRA and TST in 184 schoolchildren at high risk for LTBI. The IGRA and TST were positive in 33.2% and 43.5% of the children, respectively (P < 0.001). If studies confirm that this difference is due to higher specificity of this IGRA, it may have an important role to play in the diagnosis of LTBI and identification of children at true risk for TB.     

Comparison of IGRA and TST in the diagnosis of latent tuberculosis among women of reproductive age in South India

BackgroundLatent tuberculosis infection (LTBI) is a mycobacterial infection defined on the basis of cellular immune response to mycobacterial antigens. The tuberculin skin test (TST) and the Interferon-Gamma Release Assay (IGRA) are the two tests currently used to establish the diagnosis of LTB. Literature suggests that a study regarding tuberculosis (TB) infection among women of reproductive age group is limited.MethodsFemale household contact, married, aged 18–49 years underwent written consent form and are screened for LTBI using the TST and IGRA. Participants are injected with TST [5 tuberculin unit (TU), purified protein derivative (PPD)] and IGRA [QuantiFERON®-TB Gold Plus kit (QFT-Plus)]. All the household contacts were followed-up for one year for incident TB cases. Statistical analysis was done using STATA version 14 (StataCorp., Texas, USA). Cohen's kappa test was used to determine the agreement between two tests.ResultsThe prevalence of LTBI was found to be 69% (either TST or IGRA positive). Positivity rate of IGRA was higher when compared to that of TST. Out of 139 participants, 68 (49%) tested positive for TST, 80 (57.6%) tested positive for IGRA and 52 (37.4%) tested positive for both. Discordant results were observed in about two fifth of the study population and there was poor agreement between the two tests.ConclusionLongitudinal studies are required to detect incident TB cases to evaluate the usefulness of these tests. The study was found that IGRA is more consistent to diagnosis of latent tuberculosis infection than the TST. Such studies can also be performed in varied settings among different populations which would help us to improve the diagnosis of LTBI and consequently help in TB control.     

Screening of latent tuberculosis infection by interferon-γ release assays in rheumatic patients: a systemic review and meta-analysis

The aim of this study is to assess the diagnostic value of interferon-γ release assays (IGRAs) for latent tuberculosis infection (LTBI) in patients with rheumatic disease before receiving biologic agents. MEDLINE and EMBASE databases were used for searching studies concerning the evaluation on the performance of IGRAs [QuantiFERON-TB Gold (QFT-G), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB] in rheumatic patients before biological therapy. After assessing the quality of all studies included in the review, we summarized the results in subgroups using forest plots and calculated pooled estimates if applicable. The search identified 11 studies with a total sample size of 1940 individuals. Compared with the tuberculin skin test (TST), the pooled agreements in QFT-G/GIT and T-SPOT.TB were 72 % (95 % confidence interval (CI) 65, 78 %) and 75 % (95 % CI 67, 83 %), respectively. BCG vaccination was positively correlated with positive rates of TST (pooled odds ratio (OR) 1.64, 95 % CI 1.06, 2.53). Compared with TST, IGRAs were better associated with the presentence of one or more tuberculosis (TB) risk factors. Neither steroid nor disease-modifying anti-rheumatic drugs (DMARDs) significantly affect positive IGRA results. In contrast, TST positivity was significantly impacted by the use of steroid (pooled OR 0.45, 95 % CI 0.30, 0.69), but less significantly by the use of DMARDs (pooled OR 0.78, 95 % CI 0.50, 1.21). In conclusion, in rheumatic patients with previous BCG vaccination or currently on steroid therapy, IGRAs would be the better choice to identify LTBI by decreasing the false-positivity and false-negativity rate compared with conventional TST.     

Empfehlungen für das Tuberkulose-Screening vor Gabe von TNF-α-Inhibitoren bei rheumatischen Erkrankungen

Due to the increased risk of tuberculosis (TB) under treatment with TNF-α inhibitors for rheumatoid arthritis and other autoimmune diseases, precautionary measures are required before initiating TNF-α-inhibitor therapy. Patients should have active TB ruled out and screening for latent TB infection should be performed. The screening should include chest X-ray, complete medical history, and the administration of a highly specific interferon-γ-release assay (IGRA). (In the future, the reimbursement of IGRA tests under an analogue procedure code is expected to be formalized by the application of a code specific to the TB-IGRA procedure.) As tuberculin skin test (TST) results can be expected to be either false-positive or false-negative in these patients, the TST, as commonly performed in the past, is recommended only in exceptional situations. For chemopreventive treatment of latent TB infection (LTBI), isoniazid is usually given for 9 months.     

Contribution of a IFN-gamma assay in contact tracing for tuberculosis in a low-incidence, high immigration area

AIMS OF STUDY: to analyse, in contacts exposed to smear+/culture + (S+/C+) or S-/C+ TB, most of whom are foreign-born: 1) correlation between T-SPOT.TB IFN-gamma release assay (Oxford Immunotec, UK), TST and exposure scores; 2) agreement between T-SPOT.TB and TST in Bacillus of Calmette-Guérin (BCG) vaccinated and non-vaccinated subjects, and 3) impact of results of T-SPOT.TB on diagnosis and treatment for latent tuberculosis infection (LTBI). PATIENTS AND METHODS: TST and T-SPOT.TB were performed in 295 contacts (74% foreign-born) 8-12 weeks after exposure. Contacts completed five exposure scores. Data were analysed according to most recent US (ATS/CDC), British (NICE) and Swiss guidelines. RESULTS: T-SPOT.TB was positive in 115 (39%) and indeterminate in 15 subjects (5.1%). Neither TST, nor T-SPOT.TB was significantly related to exposure scores or infectiousness of the index case. In multivariate analysis, incidence of TB in country of origin was the strongest predictor of result of TST or T-SPOT.TB. Agreement between TST and T-SPOT.TB (kappa: 0.19-0.27) was low but improved in non BCG-vaccinated subjects (kappa: 0.28-0.47). According to guidelines referred to, 10-24% of subjects screened were T-SPOT.TB+/TST-: the prognosis of this group is yet undetermined. Another 10-27% were T-SPOT.TB-/TST+: present guidelines recommend withholding treatment for LTBI in these subjects although longitudinal data are still scarce. CONCLUSIONS: The lack of a relationship between T-SPOT.TB and exposure scores probably results from both the variability inherent to the design of this study (ie, multiple contact investigations, exposure in different settings) and limits in the performance of the IGRA tested. Longitudinal data are needed to clarify the risk of TB in T-SPOT.TB+/TST- individuals. Unreliability of diagnosis of LTBI in spite of the present use of IGRA in algorithms is illustrated by the wide variations in identification of LTBI according to different guidelines referred to.     

Screening for latent tuberculosis infection prior to biologic therapy in patients with chronic immune-mediated inflammatory diseases (IMID): Interferon-gamma release assay (IGRA) versus tuberculin skin test (TST)

BackgroundThe screening for latent tuberculosis infection (LTBI) is mandatory before initiating biologics in patients with chronic immune-mediated inflammatory disease (IMID). The recommendations are based on the tuberculin skin test (TST) and interferon-gamma release assay (IGRA).Aim of the workTo evaluate the agreement between the two tests in the diagnosis of LTBI and to identify risk factors associated with positive TST and IGRA results.Patients and methodsMedical records of 105 IMID patients going to receive a biologic agents were extracted in a cross sectional study (2015–2017). No biologics was undertaken before LTBI screening. All patients underwent IGRA and chest radiography. TST was performed in 94 cases.ResultsThe mean age of the patients was 47.7 ± 14.4 years and disease duration of 11.2 ± 7.6 years. Agreement between the 2 tests results was low (κ coefficient = 0.08). The sensitivity of TST and IGRA was equally low but the specificity of IGRA was higher. Replacing TST results by positive IGRA showed that number of patients who would take anti-tuberculous chemoprophylaxis will be significantly reduced by 46.5% (from 40.9% to 21.9%; p = 0.0002). TST results were significantly less positive for patients receiving immunosuppressives than for those receiving no treatment (35.1% vs 42.5%, p = 0.031). IGRA results were associated with absence of Bacilli Calemtte-Guérin vaccination. Age was the only risk factor for LTBI associated with both IGRA and TST positivity (p = 0.031, p = 0.011 respectively).ConclusionsTST and IGRA have a low agreement. Both tests should be included in the strategy to diagnose LTBI prior to biologic therapy in IMID patients.     

Yield and cost effectiveness of mycobacterial infection detection using a simple IGRA-based protocol in UK subjects with inflammatory bowel disease suitable for anti-TNFα therapy

Background and aimsTesting for LTBI is recommended prior to anti-TNFα agents. This includes an assessment of TB risk factors, chest radiograph, and interferon-gamma release assay alone or with concurrent Tuberculin skin testing. Here we review our experience and cost-effectiveness of using T-SPOT.TB IGRA to detect mycobacterial infection in patients with IBD suitable for anti-TNFα therapy.MethodsThis was a single-centre, retrospective review and economic evaluation (compared to British Thoracic Society guidance) of 125 adult IBD patients (90 anti-TNFα naïve, 35 established on anti-TNFα) tested for LTBI using T-SPOT.TB IGRA.ResultsAll subjects had normal chest radiographs and no clinical evidence for TB. 109 (87%) were BCG vaccinated. 27 (22%) of all patients tested were not using immunomodulation at the time of testing. 66 (53%) were taking thiopurines, 22 (18%)corticosteroids, and 35 (28%) anti-TNFα agents. One hundred twenty two (98%) had a negative IGRA result, two (2%) had positive results, and one (1%) had an indeterminate IGRA. A strategy using IGRA to guide TB preventative treatment produced cost savings of £10.79 per person compared to the BTS guidance. Eighty eight percent of the anti-TNFα naïve group have subsequently received treatment with either infliximab or adalimumab (median follow-up of 24 months, IQR 18–30) with no cases of TB disease occurring.ConclusionsThe use of a simple screening protocol for LTBI incorporating T-SPOT.TB IGRA in place of TST in a largely BCG vaccinated population, many using immunomodulatory agents, appears to work well and is a cost-effective strategy in our IBD service.     

Is the T-cell-based interferon-gamma releasing assay feasible for diagnosis of latent tuberculosis infection in an intermediate tuberculosis-burden country?

The diagnosis of active and latent tuberculosis infection (LTBI) remains a challenge, especially in light of the fact that the tuberculin skin test (TST), which has been used to diagnose LTBI for over a century, has many well-known drawbacks. This study aimed to compare the diagnostic performance of the T-cell-based interferon-gamma releasing assay (IGRA) T-SPOT.TB with the TST for the diagnosis of LTBI in an intermediate tuberculosis (TB)-burden country with high BCG coverage. For this purpose, a total of 91 participants, including culture-confirmed TB patients, healthy contacts known to have been exposed to Mycobacterium tuberculosis, and healthy volunteers, selected from a BCG-vaccinated population were recruited. The sensitivities of the T-SPOT.TB and TST were 79.3 and 25.8%, and the specificities were 75.9 and 56.7%, respectively. The negative- and positive-predictive values for T-SPOT.TB and TST were 78.6 and 76.7% and 42.5 and 38.1%, respectively. The diagnostic performance of the TST in LTBI diagnosis is therefore severely diminished in BCG-vaccinated populations, with the sensitivity and specificity of the T-SPOT.TB assay being markedly higher. IGRAs have been reported to have higher diagnostic sensitivity and specificity in low TB-incidence settings than those seen here. Further larger scale studies in high and intermediate TB-incidence settings are therefore warranted.