The Quantiferon Gold test is one of two commercially available tuberculosis (TB) interferon-γ release assays (IGRAs) recommended for the diagnosis of latent TB infection [1]. A Quantiferon Gold test is considered positive if the result is ≥0.35 IU·mL−1 [2]. However, longitudinal studies have shown that a significant number of test reversions and conversions occur if results just above or below this threshold are repeated [3, 4]. This variation may be due to random chance or other factors such as test-related errors, differences in absolute lymphocyte numbers and within-subject variability of the interferon-γ response [5, 6]. The high proportion of conversions and reversions around the 0.35 IU·mL−1 cut-off has led some to suggest that a borderline or equivocal range should be used [7], as this avoids treatment of individuals who do not have a ‘stable’ positive result, as well as failure to treat those just below the 0.35 threshold who would convert to a positive result if the test were repeated [6]. Borderline and equivocal results for the Quantiferon Gold test are common and repeated borderline tests often change http://ow.ly/PDDZ30fqJ1c

中文翻译：

---

不确定和临界 Quantiferon Gold TB IGRA 结果的频率和意义

Quantiferon Gold 测试是推荐用于诊断潜伏性 TB 感染的两种市售结核病 (TB) 干扰素-γ 释放测定法 (IGRA) 之一 [1]。如果结果≥0.35 IU·mL-1 [2]，则认为 Quantiferon Gold 测试为阳性。然而，纵向研究表明，如果重复刚好高于或低于此阈值的结果 [3, 4]，就会发生大量的测试逆转和转换。这种变化可能是由于随机机会或其他因素，例如与测试相关的错误、绝对淋巴细胞数量的差异以及干扰素-γ 反应的受试者内变异性 [5, 6]。在 0.35 IU·mL-1 临界值附近的高比例转换和逆转导致一些人建议应使用边界或模棱两可的范围 [7]，因为这避免了对没有“稳定”阳性结果的个体进行治疗，以及未能治疗那些在重复测试后会转化为阳性结果的阈值低于 0.35 的个体 [6]。Quantiferon Gold 测试的边界和模棱两可的结果很常见，重复的边界测试经常改变 http://ow.ly/PDDZ30fqJ1c