在一个结核病负担中等的国家，结核菌素皮肤试验与全血干扰素γ检测在潜伏性结核感染诊断中的差异

Discrepancy between the tuberculin skin test and the whole-blood interferon gamma assay for the diagnosis of latent tuberculosis infection in an intermediate tuberculosis-burden country.

作者信息

Kang Young Ae, Lee Hye Won, Yoon Ho Il, Cho BeLong, Han Sung Koo, Shim Young-Soo, Yim Jae-Joon

机构信息

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.

出版信息

JAMA. 2005 Jun 8;293(22):2756-61. doi: 10.1001/jama.293.22.2756.

DOI:10.1001/jama.293.22.2756

PMID:15941805

Abstract

CONTEXT

A recently developed whole-blood interferon gamma (IFN-gamma) assay based on stimulation with the Mycobacterium tuberculosis-specific antigens early secreted antigenic target 6 and culture filtrate protein 10 shows promise for the diagnosis of latent tuberculosis (TB) infection.

OBJECTIVE

To compare the tuberculin skin test (TST) and the whole-blood IFN-gamma assay in the diagnosis of latent TB infection according to the intensity of exposure.

DESIGN AND SETTING

A prospective comparison between the whole-blood IFN-gamma assay and the TST using a 2-TU dose of purified protein derivative RT23 in a population with intermediate TB burden was conducted sequentially between February 1, 2004, and February 28, 2005, in a Korean tertiary referral hospital.

PARTICIPANTS

Of 273 participants, 220 (95.7%) had received BCG vaccine. Participants were grouped according to their risk of infection: group 1, no identifiable risk of M tuberculosis infection (n = 99); group 2, recent casual contacts (n = 72); group 3, recent close contacts (n = 48); group 4, bacteriologically or pathologically confirmed TB patients (n = 54).

MAIN OUTCOME MEASURES

Levels of agreement between the TST and the IFN-gamma assay and the likelihood of infection in the various groups.

RESULTS

For the TST with a 10-mm induration cutoff, the positive response rate in group 1 was 51%; group 2, 60%; group 3, 71%, and group 4, 78%. For the IFN-gamma assay, the positive response rate in group 1 was 4%; group 2, 10%; group 3, 44%; and group 4, 81%. The overall agreement between the TST and the IFN-gamma assay in healthy volunteers was kappa = 0.16. The odds of a positive test result per unit increase in exposure across the 4 groups increased by a factor of 5.31 (95% confidence interval [CI], 3.62-7.79) for the IFN-gamma assay and by a factor of 1.52 (95% CI, 1.20-1.91) for the TST (P<.001). Using a 15-mm induration cutoff for the TST did not make a substantial difference to the test results.

CONCLUSION

The IFN-gamma assay is a better indicator of the risk of M tuberculosis infection than TST in a BCG-vaccinated population.

摘要

背景

最近开发的一种基于用结核分枝杆菌特异性抗原早期分泌抗原靶标6和培养滤液蛋白10刺激的全血干扰素γ（IFN-γ）检测方法，在潜伏性结核（TB）感染的诊断中显示出前景。

目的

根据接触强度比较结核菌素皮肤试验（TST）和全血IFN-γ检测在潜伏性TB感染诊断中的效果。

设计与地点

2004年2月1日至2005年2月28日期间，在韩国一家三级转诊医院，对一组结核病负担中等的人群，依次进行了全血IFN-γ检测与使用2个结核菌素单位剂量的纯化蛋白衍生物RT23的TST之间的前瞻性比较。

参与者

273名参与者中，220名（95.7%）接种过卡介苗。参与者根据感染风险分组：第1组，无明确的结核分枝杆菌感染风险（n = 99）；第2组，近期偶然接触者（n = 72）；第3组，近期密切接触者（n = 48）；第4组，细菌学或病理学确诊的TB患者（n = 54）。

主要观察指标

TST与IFN-γ检测之间的一致性水平以及各组感染的可能性。

结果

对于硬结直径截断值为10毫米的TST，第1组的阳性反应率为51%；第2组为60%；第3组为71%，第4组为78%。对于IFN-γ检测，第1组的阳性反应率为4%；第2组为10%；第3组为44%；第4组为81%。健康志愿者中TST与IFN-γ检测的总体一致性为kappa = 0.16。在4组中，随着接触程度每增加一个单位，IFN-γ检测呈阳性结果的几率增加5.31倍（95%置信区间[CI]为3.62 - 7.79），而TST为1.52倍（95% CI为1.20 - 1.91）（P <.001）。将TST的硬结直径截断值设为15毫米对检测结果没有实质性影响。