QuantiFERON-TB Gold In-Tube as help for the diagnosis of tuberculosis in a French pediatric hospital

The diagnosis of tuberculosis (TB) is difficult in children. The pediatricians are waiting for new and rapid tests that are easy to realize and that are performed better than tuberculin skin test (TST). We presented here the evaluation of QuantiFERON^®-TB Gold In-Tube (QFT-G IT) in the Children Hospital of Nancy. Fifty-one children were divided into 3 groups: healthy contacts (HC, n = 31), latent TB infection (LTBI, n = 13), and active TB (n = 7). QFT-G IT was positive in 0%, 15%, and 43% of children compared with 3%, 70%, and 57% for TST, respectively, for the HC, LTBI, and active TB groups. Indeterminate QFT-G IT occurred in 14% of the cases, seemed to correlate with young age, and was not explained by preanalytic parameters. In conclusion, despite its objectivity and its higher specificity (especially in Bacille Calmette–Guérin vaccinated children), the real place of QFT-G IT in TB diagnosis in children remains difficult to define.     

结核菌素皮肤试验阳性人群是否应该接受化学预防治疗

结核病是我国常见的呼吸道传染病之一,发病率和死亡率仍居传染病之首。WHO估计全球有1/3的人口感染结核分枝杆菌(MTB),即潜伏结核感染者(LTBI),而我国是结核病高负担国家之一,大约有40%⁴5%的人口感染MTB。LTBI者在2年内发展成为有临床表现的活动性结核病的风险为5%45%的人口感染MTB。LTBI者在2年内发展成为有临床表现的活动性结核病的风险为5%¹0%,如果采取化学预防,可以降低LTBI者2年内的发病率。LTBI的检测最常用的方法是结核菌素皮肤试验(TST),但并非所用TST阳性人群均适宜化学预防。在我国对于TST强阳性人群,尤其是结核病的高危人群,适合采取化学预防治疗。预防方案可以是单药异烟肼,也可以是异烟肼联合利福平或利福喷汀预防治疗,疗程及给药方式没有统一标准。     

New tools and emerging technologies for the diagnosis of tuberculosis: part I. Latent tuberculosis

Nearly a third of the world's population is estimated to be infected with Mycobacterium tuberculosis. This enormous pool of latently infected individuals poses a major hurdle for global tuberculosis (TB) control. Currently, diagnosis of latent TB infection (LTBI) relies on the tuberculin skin test (TST), a century-old test with known limitations. In this review, the first of a two-part series on new tools for TB diagnosis, recent advances in the diagnosis of LTBI are described. The biggest advance in recent years has been the development of in vitro T-cell-based interferon-gamma release assays (IGRAs) that use antigens more specific to M. tuberculosis than the purified protein derivative used in the TST. Available research evidence on IGRAs suggests they have higher specificity than TST, better correlation with surrogate markers of exposure to M. tuberculosis in low-incidence settings, and less cross-reactivity due to BCG vaccination than the TST. IGRAs also appear to be at least as sensitive as the purified protein derivative-based TST for active TB. In the absence of a gold standard for LTBI, sensitivity and specificity for LTBI are not well defined. Besides high specificity, other potential advantages of IGRAs include logistical convenience, avoidance of poorly reproducible measurements, such as skin induration, need for fewer patient visits and the ability to perform serial testing without inducing the boosting phenomenon. Overall, due to its high specificity, IGRAs may be useful in low-endemic, high-income settings where cross-reactivity due to BCG might adversely impact the utility of TST. However, despite the growing evidence supporting the use of IGRAs, several unresolved and unexplained issues remain. The review concludes by highlighting areas where evidence is lacking, and provides an agenda for future research. Active TB and drug resistance are discussed in Part II; 423-432 of this issue.     

Comparison of tuberculin skin test and a specific T-cell-based test, T-Spot.TB, for the diagnosis of latent tuberculosis infection

There is substantial evidence that the detection of T cells specific for the proteins ESAT-6 and CFP-10 using the ex vivo enzyme-linked immunospot technique is a marked improvement on the existing tuberculin skin test (TST). This new technique, which detects gamma-interferon-producing T cells, is now available as the commercial assay, T-Spot.TB. We compared the T-Spot.TB test with the TST for the diagnosis of latent tuberculosis infection (LTBI) in different groups of subjects. Significant accordance (85.7%) between the tests was found in subjects with active lung tuberculosis and in tuberculosis clinic and laboratory personnel (63.6%) but accordance was lowest and not significant amongst house contacts of tuberculosis patients (53.6%). We conclude that, in countries where vaccination is routinely performed, the T-Spot.TB test is a useful diagnostic test for LTBI in high-risk groups when carried out either together with the TST and/or to confirm the TST result.     

The role of a whole blood interferon-gamma assay for the detection of latent tuberculosis infection in Bacille Calmette-Guérin vaccinated children

The tuberculin skin test (TST) has limitations in children who are under the Bacille Calmette-Guérin (BCG) effect. Our aim was to evaluate the QuantiFERON-TB Gold In-Tube (QFT-G IT) blood test for Mycobacterium tuberculosis infection in children and to compare results with those of the TST. QFT-G IT and TST data were collected from 227 children between 0 and 15 years of age, split into 4 risk groups. Forty-two children were close contacts, 29 were casual contacts, and 65 were controls. The QFT-G IT positivity rates were 19% (8/42), 6.9% (2/29), and 1.5% (1/65), with a significantly higher rate for the close contacts over the controls (P < 0.05). The high specificity of the QFT-G IT assay and the association of positive results with increasing risk of infection in our study suggest it has major benefits over the TST as a screening test for latent infection with M. tuberculosis in BCG-vaccinated children.     

结核分枝杆菌感染人群诊断及预防治疗研究进展

结核潜伏感染(LTBI)者是结核病患者的重要来源,可通过免疫学方面检测(结核菌素试验和γ-干扰素释放试验)诊断,对LTBI的预防性治疗可以减低将来结核分枝杆菌再活化及发展成结核病的风险。LTBI的检测属于针对性检测,只有对于有高风险发展成结核病或者能从LTBI的预防性治疗中获益的人群才进行LTBI的检测。常用的标准预防性治疗方案是6⁹个月的异烟肼治疗方案,可以降低LTBI 90%的发病风险,由于疗程长、肝损害常见,完成率仅仅在50%左右。针对上述问题衍生出了一些其他的单药或者联合用药的方案,包括4RIF、3INH-RPT、3-4INH-RIF及2RIF-PZA,其中有效性、安全性和完成率均较好的是3INH-RPT。预防性治疗既往并未得到有效利用,对LTBI的规范诊疗将有助于实现国家结核病防治规划。     

Comparison of an in-house and a commercial RD1-based ELISPOT-IFN-gamma assay for the diagnosis of Mycobacterium tuberculosis infection

OBJECTIVE: To compare a RD1-based in-house ELISPOT-interferon-gamma (IFN-gamma) assay with a commercial (T-SPOT.TB) assay for the diagnosis of Mycobacterium tuberculosis (TB) infection and the efficacy of the tuberculin skin test (TST) and ELISPOT assay in detecting latent TB infection (LTBI). DESIGN: Eighty-six subjects (65 household contacts of contagious TB-infected patients, 13 subjects with active or previous TB infection, and 8 with suspected TB infection) were consecutively recruited in the context of a surveillance program. METHODS: Enrolled subjects underwent the Mantoux TST and two different ELISPOT-IFN-gamma assays: an in-house assay using a pool of selected M. tuberculosis peptides (MTP) and the commercial T-SPOT.TB assay. RESULTS: The in-house and commercial ELISPOT-IFN-gamma assays showed almost complete concordance (99%) in diagnosing acute or LTBI.When comparing the efficacy of the TST with the in-house ELISPOT assay in detecting TB infection, a small agreement was observed (k=0.344, P<0.0001): 36% of the subjects with a positive TST were ELISPOT-MTP negative and 12% with a negative TST were ELISPOT-MTP positive. Furthermore, 78% of the ELISPOT-MTP negative individuals were ELISPOT- Bacillus Calmette-Guérin (BCG) positive, most of whom had received BCG vaccination. CONCLUSION: Our in-house ELISPOT assay based on a restricted pool of highly selected peptides is equivalent to the commercial T-SPOT.TB assay, is cheaper and is probably not confounded, unlike the TST, by BCG vaccination in our setting.     

Comparison of QuantiFERON TB‐G‐test to TST for detecting latent tuberculosis infection in a high‐incidence area containing BCG‐vaccinated population

Objective Until recently, the only tool for detection of latent tuberculosis infection (LTBI) was the tuberculin skin test (TST). QuantiFERON‐TB Gold In‐Tube test (QFT) is a promising in vitro diagnostic test for LTBI that has potential advantages over the TST. In this study we aimed to compare QFT with TST for diagnosis of LTBI. Patients and methods A total of 186 BCG‐vaccinated subjects enrolled in study. They underwent TST and QFT assay. They divided in two groups. Group 1 includes individuals who were at low risk for exposure to M. tuberculosis (LRG) and Group 2 includes individuals who were likely to have been exposed to M. tuberculosis infections (HRG). Results Overall agreement between QFT and TST was 89.3% (kappa = 0.052). In LRG, agreement between the two tests was 52.6% (95% confidence interval, 44–60%) with κ‐values of 0.019. In HRG agreement between the two tests was 63.2% (95% confidence interval, 42–84%) with κ‐values of 0.28. Conclusion In conclusion, the QFT assay showed acceptable results for determining latent M. tuberculosis infection in vaccinated population. The decision to select QFT over TST will depend on the population, purpose of testing and resource availability.     

QFT test and TST test in diagnosis of TB infection

At present, there are only two methods to diagnose tuberculosis infection in the world, tuberculin skin test (TST) and interferon gamma release assays (IGRAs). Since TST could show positive responses due to BCG vaccination or infection of non-tuberculous mycobacterium and BCG vaccination is widely done in Japan, TST has a critical problem in its specificity. QuantiFERON-TB Gold (QFT-G/QFT-3G) is one of IGRAs and uses M. tuberculosis-specific antigens (ESAT-6, CFP-10, TB7.7) for stimulation of whole blood to induce IFN-gamma production by antigen-specific T cells. Produced IFN-gamma is measured by ELISA system. IFN-gamma is produced by individuals with TB infection but not by BCG-vaccinated individuals without TB infection. As QFT can detect TB infection among BCG vaccinated individuals more accurately than TST, it is possible to diagnose TB infection efficiently in contact investigation so on. However, as same as TST, QFT cannot discriminate between remote infection and recent infection, nor between progressive infection and controllable recent infection. Since QFT is newly development TB diagnosis test, there are many subjects in the QFT test system. For example, one subject is that accurate QFT results among immunocompromised populations are difficult to obtain because of weak immune responses. After these many research data are accumulated, we will be able to have many solutions in QFT.     

γ-干扰素释放试验筛查潜伏性结核患者的成本效果分析

目的 利用模型假设对结核密切接触者分别实施:结核菌素试验(TST试验)或T.SPOT试验单用(即单用)和TST阳性者追加使用T.SPOT试验策略(即联用),分析不同筛查策略的成本效果,为我国推广利用T.SPOT试验筛查潜伏性结核提供经济学依据.方法 假设1 000名结核密切接触者分别接受上述3种筛查策略.使用TreeAge Pro 2004软件构建决策树模型并设定模型假设条件.模型时间假设为1年.选取预防1例活动性结核所需的增量成本为结局指标并进行单因素敏感性分析.收集官方数据和已发表文献数据并进行Meta分析确定率值参数.成本数据来源首选各省官方数据,其余数据联系医院获取.结果 ①T.SPOT试验总成本最高(212 213.81元/千人),TST试验次之,TST与T.SPOT联用总成本成本最低;②预防1例活动性结核需要筛查的潜伏性结核患者人数,TST试验最多,达25.67例;TST与S.SPOT联用最少,仅8.31例.③预防1例活动性结核,TST与T.SPOT联用所致的增量成本最小,为3 063.50元,T.SPOT试验次之,TST试验最高;④在其他参数不变情况下,患病率达到60%或TST试验灵敏度或特异度分别达到70%以上时,TST单用成本效果优于T.SPOT单用.结论 T.SPOT单用可提高预防活动性结核的例数,T-SPOT与TST联用较二者成本效果更好.患病率、TST试验效果指标会影响成本效果,但联用成本效果始终最高.     

Living donor and recipient screening for latent tuberculosis infection by tuberculin skin test and interferon-gamma releasing assay in a country with an intermediate burden of tuberculosis

There are few data on donor screening for latent tuberculosis infection (LTBI) using the tuberculin skin test (TST) and interferon-gamma releasing assay (IGRA). In South Korea, most renal allografts involve living donors (average, 80 %). Hence, we have an opportunity to evaluate donor and recipient screening for LTBI by TST and IGRA. All donors and recipients admitted for kidney transplantation during a 20-month period were evaluated prospectively by using TST and Mycobacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay. The study population consisted of 205 living donor–recipient pairs (≥16 years) including 15 (7 %) who yielded indeterminate donor or recipient ELISPOT results. Of the 205 donors, 63 (31 %) gave a positive TST ≥5 mm, 33 (16 %) a positive TST ≥10 mm, and 96 (47 %) a positive ELISPOT. Of the 205 recipients, 9 (5 %) gave a positive TST ≥5 mm, 3 (2 %) a positive TST ≥10 mm, and 79 (39 %) had a positive ELISPOT. Of the 205 donor–recipient pairs, only 59 (29 %) gave negative donor and recipient ELISPOT results and 139 (68 %) negative donor and recipient TSTs (<5 mm) (P < 0.001). One third of donor–recipient pairs tends to be positive in the TST, and two thirds of the donor–recipient pairs tends to be positive in the ELISPOT. Given the high positive rate of LTBI obtained by screening donors, further studies on the clinical value of solid organ transplant donors with positive TST or ELISPOT and health economics analysis in countries with intermediate burden of TB are needed for policy decisions on isoniazid (INH) prophylaxis.     

结核潜伏性感染诊断研究进展

结核潜伏性感染(latent tuberculosis infection,LTBI)是宿主感染结核分枝杆菌后尚未发病,无活动性结核的临床表现、影像学改变或细菌学证据的一种特殊状态。潜伏性感染者如不进行治疗,约有5%~10%会发展成活动性结核。早期识别和治疗结核潜伏感染者,是结核病防治的重要策略之一。本文综述了国内外诊断潜伏感染的结核菌素试验(TST)和干扰素释放试验(IGRA)检测方法、两种方法的优缺点以及使用方面的选择,为开展现场调查和有关研究提供参考。     

T-SPOT.TB assay usage in adults and children

The diagnosis and treatment of TB infection is one of the public health priorities. Until recently, diagnosis of TB infection has been based on the tuberculin skin test (TST). However, this is neither 100% sensitive nor specific for the diagnosis of TB infection owing to its many drawbacks. More recently, T-cell-based IFN-γ release assays (IGRAs) have been developed. In this article, we review the clinical performance of one of the IGRAs, T-SPOT.TB assay, for the diagnosis of TB infection in adults and children. We discuss the principle of the assay, its utility in active TB diseases, latent TB infection and the performance of the test in specialized subgroups of patients, such as immunocompromised individuals. When compared with the TST, the T-SPOT.TB assay has better specificity in bacillus Calmette-Guérin-vaccinated individuals, and data suggest that T-SPOT.TB may be more sensitive than the TST. Data in groups at high risk of progression to disease support the idea that T-SPOT.TB performs better than the TST. In addition, application of T-SPOT.TB by using bodily fluids such as cerebrospinal fluid, bronchoalveolar lavage fluid and pleural fluid may offer new diagnostic approaches in extrapulmonary TB disease. Although IGRAs cannot distinguish active TB disease from latent TB infection, these assays perform better than the TST for the detection of TB infection.     

New tests will improve detection of latent TB

In the UK cases of active TB have risen substantially over the past 20 years. This increase has occurred almost exclusively in individuals born outside the UK, who now constitute more than two-thirds of cases. Only around one in ten people who are infected will develop active disease. The remaining 90% are presumed to have latent TB infection (LTBI) where viable mycobacteria are thought to persist for decades, and may reactivate if the host's immune system is weakened. In a country such as the UK with a low incidence of TB, a high proportion of cases result from reactivation of latent TB, rather than transmission by infectious cases. In the past 10 years a novel type of diagnostic test for LTBI has been developed: the interferon-gamma release assays (IGRA). Their major advantage over the tuberculin skin test is that they are not affected by prior BCG vaccination and they have a specificity of well over 90%. These tests are unable to distinguish between active and latent TB infection: this distinction must be performed purely on clinical grounds. Patients with a positive test should be assessed by a clinician with expertise in TB to ensure an appropriate management plan for each patient. The role of IGRAs in diagnosis of active TB is limited since in a patient with suspected active TB a positive result may indicate LTBI in combination with an alternative diagnosis. At a population level screening and chemoprophylaxis contributes usefully to TB control. However, only those under 35 with LTBI should receive prophylaxis. After this age the increasing risks of hepatotoxicity begin to outweigh the diminishing benefits of prophylaxis. The exceptions are healthcare workers, where the benefits are not just to the individual but also extend to their patients, and immunocompromised patients. The IGRAs represent a major development in the diagnosis of LTBI. While currently most of their use is through established TB screening services, it is likely in future that they will also be used routinely in general practice to screen individuals at high risk of LTBI.     

Latent tuberculosis infection screening for laboratory personnel using interferon-γ release assay and tuberculin skin test in Korea: an intermediate incidence setting

Background: Though recent reports have indicated a higher prevalence of latent tuberculosis infection (LTBI) in laboratory personnel than in other healthcare workers, these studies included only a limited number of laboratory personnel. Methods: We have thus focused on the laboratory personnel, who had a high level of exposure to specimens from patients with TB. We recruited 173 laboratory personnel and performed QuantiFERON‐TB Gold In‐Tube test (QFT‐G) and tuberculin skin test (TST). Results: QFT‐G was positive in 21.4% of the enrolled laboratory personnel, and TST was positive in 33.3%. The agreement between the two tests was fair (κ = 0.234). In multivariate analyses, household contactwith TBpatients (P = 0.013), the laboratory sections of microbiology (P = 0.045) and chemistry/immunology (P = 0.014) were shown to be significantly associated with positive QFT‐G results. Conclusion: Our data show a high prevalence of TST and QFT‐G positivity in laboratory personnel and emphasize the importance of LTBI screening for laboratory personnel. In BCG‐vaccinated populations with an intermediate incidence setting, QFT‐G seems to be superior to TST as a screening tool for the detection of LTBI. Further study, including results of follow‐up tests will be helpful for confirmation of our findings. J. Clin. Lab. Anal. 25:382–388, 2011. © 2011 Wiley Periodicals, Inc.     

Risk factors for latent tuberculosis infection in children in South Korea

Objectives: In South Korea, latent tuberculosis infection (LTBI) screening is a critical strategy associated with efforts to reduce the incidence of tuberculosis (TB). Currently, only children with a known history of TB contact are considered as pediatric high-risk groups for LTBI, and consequently, LTBI screening is only provided to these children. However, to reduce the incidence of TB, the high-risk groups that undergo LTBI screening should be expanded. This study aimed to assess the risk factors for LTBI among children living in South Korea with no known history of TB contact for the identification of additional high-risk groups. We investigated the risk factors for LTBI among US visa applicant children, who undergo LTBI screening regardless of their TB contact history.

Methods: We obtained data on demographic characteristics, medical history, Bacillus Calmette–Guerin (BCG) vaccination history, and results of LTBI screening for children aged 2–14 years. A tuberculin skin test was used for the diagnosis of LTBI, and an induration of 10 mm or greater was used to define a positive test. Adjusted odds ratios and 95% confidence intervals were calculated to determine the association between clinical and demographic variables and LTBI.

Results: Of the 1,664 study participants, 91 (5.5%) had LTBI. The binary logistic regression analysis showed that children born in high TB burden foreign countries had the highest odds of LTBI when considering all the risk factors investigated. Increasing age, absence of BCG vaccination, and a previous diagnosis of asthma were also significant risk factors for LTBI.

Conclusion: These results indicate that children born in high TB burden foreign countries should be considered a high-risk group for LTBI in South Korea; the inclusion of these children in LTBI screening should be considered.     

Positivity rate of interferon-γ release assays for estimating the prevalence of latent tuberculosis infection in renal transplant recipients in Japan

Renal transplant recipients are at increased risk of reactivating latent tuberculosis infection (LTBI) and developing active tuberculosis. QuantiFERON^®-TB Gold Plus (QFT-Plus) has two TB-specific antigens tubes (TB1 and TB2). TB1 elicits CD4 T-cell response, and TB2 elicits both CD4 and CD8 T-cells responses, with expected increased sensitivity.The aim of this study was to estimate the prevalence of LTBI in renal transplant recipients in Japan. We conducted a cross-sectional study by using two interferon-γ release assays (IGRAs), QFT-Plus and T-SPOT^®.TB (TSPOT).One hundred thirty-five recipients were prospectively enrolled. The median age was 49 years (range: 20 to 79). The positivity rates of QFT-Plus and TSPOT were 5.9% (95%CI 3.0–11.3) and 3.7% (95%CI 1.6–8.4), respectively, with no significant difference. The concordance rate was 95.5% (κ coefficient, 0.76). Age of 60 years and higher was related to the higher positivity rate in both QFT-Plus and TSPOT. The positivity rates of TB1 and TB2 were 5.1% (95%CI 2.5–10.2) and 5.9% (95%CI 3.0–11.2), respectively, with no significant difference. The concordance rate was 99.3% (κ coefficient, 0.93). TB2 did not show a higher positivity rate compared with TB1.The estimated prevalence of LTBI by using the both IGRAs was 3.7–5.9% in renal transplant recipients. These results were equivalent to the IGRAs positivity rate in the general Japanese population, even under the condition of immunosuppressive therapy. In consideration of the higher risk of developing active TB from LTBI, we can use both IGRAs as acceptable tools for LTBI diagnosis in renal transplant recipients.     

Specificity of tuberculin skin test improved by BCG immunization schedule change in Japan

IntroductionTuberculin skin test (TST) has been used to diagnose tuberculosis (TB) and latent tuberculosis infection (LTBI). However, in Bacillus Calmette-Guérin (BCG) vaccinated patients, TST tends to produce false-positive results. According to the previous vaccination schedule, Japanese people were mandated to receive up to three doses of BCG-vaccine. The vaccination schedule was changed in 2003 and as per the new schedule, only infants are administered a dose of BCG vaccine. Our hypothesis is that this change can lead to a reduction in the cross-reaction to TST.MethodsWe evaluated the TST results obtained from 1097 recruits from six defense camps and 667 recruits from an air base. These TST data were divided into two groups according to the date of birth: a new group and an old group according to the BCG immunization schedule. We then analyzed positive and negative reaction of TST and erythema sizes.ResultsWe confirmed that the change in BCG-vaccination schedule significantly decreased TST false-positive reaction (P_meta = 1.4 × 10⁻¹⁸; risk ratio = 0.83; 95% confidence interval: 0.80–0.87) and erythema size (P_meta = 1.1 × 10⁻⁴; mean difference = 6.6 mm; 95% confidence interval: 3.2 mm–9.9 mm).ConclusionsWe showed the reduction in BCG cross-reaction to TST, in the new BCG vaccination schedule group, compared to the old group, we also have extracted information on the improvement in the specificity of TST for LTBI and TB diagnosis, which resulted from BCG schedule change.     

不同诊断技术用于肺外结核病辅助诊断的临床价值比较

目的比较结核菌素试验(TST)和结核感染T细胞斑点试验(T-SPOT.TB)用于肺外结核病(EPTB)辅助诊断的临床价值。方法回顾性分析南通市如东县中医院2017年1月至2019年5月收治的行TST和T-SPOT.TB检测的EPTB患者(64例,EPTB组)和非结核性疾病患者(106例,对照组)的临床资料,比较两种检测技术诊断的灵敏度、特异度、阳性预测值及阴性预测值,并行ROC曲线分析两种方法的诊断效能。结果T-SPOT.TB辅助诊断EPTB的灵敏度、特异度、阳性预测值及阴性预测值均明显优于TST(P<0.05);ROC曲线分析显示,TST和T-SPOT.TB辅助诊断EPTB曲线下面积分别为0.633(95%CI:0.501~0.749)、0.892(95%CI:0.812~0.974)。结论T-SPOT.TB用于EPTB辅助诊断的灵敏度与特异度高,诊断效能佳,临床应用价值优于TST。     

γ干扰素释放试验在结核病诊断中的应用价值

目的分析γ干扰素释放试验(IGRA)在结核病诊断中的应用价值。方法收集2017年11月-2019年1月广州南方医院796例进行IGRA检测的住院患者资料,分析IGRA对结核病的诊断价值,并将其与痰涂片抗酸染色镜检、结核抗体胶体金法、结核分枝杆菌DNA荧光定量PCR法、结核菌素皮肤试验(TST)、结核分枝杆菌感染T细胞斑点试验(T-SPOT.TB)进行比较。结果 IGRA对肺结核和肺外结核检出阳性率分别为80.2%和84.1%,差异无统计学意义(P>0.05);肺结核组与非结核组阳性率差异有显著统计学意义(P<0.01)。IGRA对结核诊断的灵敏度、特异度、阳性预测值和阴性预测值分别为 81.9%、81.3%、60.1%和92.9%。痰涂片抗酸染色镜检、结核抗体胶体金法、结核分枝杆菌DNA荧光定量PCR法、TST、T-SPOT.TB的灵敏度分别为3.4%、21.1%、15.2%、66.7%、82.9%。结论 IGRA灵敏度和阴性预测值较好,对结核辅助诊断具有较高临床应用价值。