Kobashi Y, Sugiu T, Mouri K, Obase Y, Miyashita N, Oka M
Division of Respiratory Diseases, Dept of Medicine, Kawasaki Medical School, Matsushima, Kurashiki, Japan.
Eur Respir J. 2009 Apr;33(4):812-5. doi: 10.1183/09031936.00075008. Epub 2009 Jan 7.
The present authors assessed risk factors that can promote indeterminate results of QuantiFERON TB-2G (QFT-2G; Cellestis Ltd, Carnegie, Australia) tests. The subjects were 704 patients with suspected tuberculosis (TB) and latent TB infection between January 2005 and December 2007. The QFT-2G test and the tuberculin skin test (TST) were performed for all subjects. If the results of the QFT-2G test were indeterminate, the test was repeated within 1 month. In total, 72 (10.2%) patients showed indeterminate results on the QFT-2G test. Indeterminate results were due to positive control failure in 68 (88.9%) patients and negative control failure in four patients. The results of the TST were negative for 64 patients showing indeterminate results, the remaining eight patients showed a positive response to the TST. Indeterminate results were significantly associated with elderly and immunocompromised patients. Lymphocytopaenia and hypoalbuminaemia were significantly associated with indeterminate laboratory findings. When the QFT-2G test was repeated for all patients showing indeterminate results, 12 (16.7%) patients demonstrated determinate results on the subsequent test. Indeterminate results of the QuantiFERON TB-2G test under routine clinical practice are not infrequent. When scoring QuantiFERON TB-2G test results for elderly and immunocompromised patients, one must be careful because the possibility of obtaining determinate results may be low even if the test is repeated.
本研究作者评估了可能导致QuantiFERON TB-2G（QFT-2G；澳大利亚卡内基Cellestis有限公司）检测结果不确定的风险因素。研究对象为2005年1月至2007年12月期间704例疑似结核病（TB）和潜伏性TB感染的患者。对所有受试者均进行了QFT-2G检测和结核菌素皮肤试验（TST）。如果QFT-2G检测结果不确定，则在1个月内重复检测。共有72例（10.2%）患者的QFT-2G检测结果不确定。结果不确定是由于68例（88.9%）患者阳性对照失败和4例患者阴性对照失败所致。64例结果不确定的患者TST结果为阴性，其余8例患者TST呈阳性反应。结果不确定与老年和免疫功能低下患者显著相关。淋巴细胞减少症和低白蛋白血症与实验室检查结果不确定显著相关。对所有结果不确定的患者重复进行QFT-2G检测时，12例（16.7%）患者在后续检测中显示出确定的结果。在常规临床实践中，QuantiFERON TB-2G检测结果不确定并不罕见。在对老年和免疫功能低下患者的QuantiFERON TB-2G检测结果进行评分时，必须谨慎，因为即使重复检测，获得确定结果的可能性也可能较低。
