Cho Kiwon, Cho Eunha, Kwon Soohoon, Im Sanghyuk, Sohn In, Song Sookhee, Kim Hyeok, Kim Suhyun
Department of Internal Medicine, Seoul Medical Center, Seoul, Korea.
Tuberc Respir Dis (Seoul). 2012 May;72(5):416-25. doi: 10.4046/trd.2012.72.5.416. Epub 2012 May 29.
The sensitivities and specificities of interferon-gamma release assays (IGRAs) vary among different population studies, and the data on the routine use of IGRAs are limited. The aim of this study was to evaluate the role of QuantiFERON-TB Gold In-Tube (QFT-GIT) test in the diagnosis of active tuberculosis.
We conducted a prospective study, enrolling 77 patients with suspected pulmonary tuberculosis (TB), at a secondary care teaching hospital in Seoul.
In total, 12 (15.6%) patients showed indeterminate results due to positive control failure on the QFT-GIT test. Indeterminate results were significantly associated with the elderly, history of the intensive care unit stay, lymphocytopenia, especially low CD4 count, increased C-reactive protein and decreased protein levels. Of the 77 patients, 44 (57.1%) were diagnosed with active pulmonary tuberculosis, and the percentage of false negative results of the QFT-GIT was 36.4% (vs. 31.8% with TST). In the TB group with >65 years old (n=12), the proportions of the indeterminate (33.3% vs. 3.1%) and the false negative results (58.3% vs. 25.0%) of the QFT-GIT were significantly higher than in the younger TB group (n=32).
Indeterminate and false negative results of QFT-GIT test were not infrequent in tuberculosis, especially in the elderly. Care should be considered for the interpretation with the elderly, immunocompromised, chronic and severely diseased patients.
不同人群研究中，γ-干扰素释放试验（IGRAs）的敏感性和特异性有所不同，关于IGRAs常规应用的数据有限。本研究旨在评估全血γ-干扰素释放试验（QFT-GIT）在活动性肺结核诊断中的作用。
我们在首尔一家二级护理教学医院开展了一项前瞻性研究，纳入77例疑似肺结核患者。
总共12例（15.6%）患者因QFT-GIT试验阳性对照失败而出现不确定结果。不确定结果与老年人、入住重症监护病房史、淋巴细胞减少（尤其是低CD4计数）、C反应蛋白升高和蛋白水平降低显著相关。77例患者中，44例（57.1%）被诊断为活动性肺结核，QFT-GIT试验的假阴性结果百分比为36.4%（结核菌素皮肤试验为31.8%）。在年龄>65岁的肺结核组（n = 12）中，QFT-GIT试验不确定结果（33.3%对3.1%）和假阴性结果（58.3%对25.0%）的比例显著高于年轻肺结核组（n = 32）。
QFT-GIT试验的不确定和假阴性结果在肺结核中并不少见，尤其是在老年人中。对于老年人、免疫功能低下者、慢性病患者和重症患者的结果解读应谨慎。
