Division of Nephrology, Geneva University Hospitals, Geneva, Switzerland.
Transplantation. 2013 Jun 27;95(12):1485-90. doi: 10.1097/TP.0b013e3182907073.
Renal transplant recipients (RTRs), as all immunosuppressed patients, are at increased risk of reactivating latent tuberculosis infection (LTBI). Detecting LTBI in this population is therefore important to prevent active TB. The tuberculin skin test (TST) has a poor sensitivity in this setting.
The aim of this prospective study was to compare the diagnostic performance of the TST and two interferon-γ release assays (IGRAs): T-SPOT.TB (Oxford Immunotec, Oxford, UK) and QuantiFERON Gold In-Tube (QGIT; Cellestis, Australia), performed simultaneously, for the detection of patients with risk factors for LTBI or a definite history of TB among RTRs under stable immunosuppression.
Two hundred five patients (ages 59±13 years, tested 10.4±7.1 years after transplantation) were studied. Positivity rate was 4.5% for TST, 20.5% for T-SPOT.TB, and 23.5% for QGIT. Agreement between IGRAs was fair (κ=0.71). Sensitivity of T-SPOT.TB and QGIT for detection of prior active TB was 55.6% (95% confidence interval [CI], 21.2-86.3) and 44.4 (95% CI, 13.7-78.8), respectively. Sensitivity of both IGRAs for detection of risk factors for LTBI was 33.3% (95% CI, 19.6-49.5). Specificity was 85.5% (95% CI, 78.9-90.7) for T-SPOT.TB and 80.1% (95% CI, 72.9-86.2) for QGIT. Combining IGRAs did not significantly improve sensitivity.
Because their sensitivity for detecting prior active TB and probable LTBI in RTRs is very low, IGRAs cannot be used to exclude LTBI. These results emphasize the limitations of IGRAs in the setting of chronic immunosuppressive therapy.
肾移植受者（RTR）与所有免疫抑制患者一样，具有潜伏性结核感染（LTBI）再激活的风险增加。因此，检测 LTBI 对于预防活动性结核病非常重要。在这种情况下，结核菌素皮肤试验（TST）的敏感性较差。
本前瞻性研究的目的是比较 TST 和两种干扰素-γ释放测定（IGRAs），即 T-SPOT.TB（Oxford Immunotec，英国牛津）和 QuantiFERON Gold In-Tube（QGIT；Cellestis，澳大利亚）的诊断性能，这些检测同时用于检测处于稳定免疫抑制状态下的 RTR 中具有 LTBI 危险因素或明确结核病病史的患者。
共研究了 205 例患者（年龄 59±13 岁，移植后检测时间为 10.4±7.1 年）。TST 阳性率为 4.5%，T-SPOT.TB 为 20.5%，QGIT 为 23.5%。IGRAs 之间的一致性为中度（κ=0.71）。T-SPOT.TB 和 QGIT 检测既往活动性结核病的敏感性分别为 55.6%（95%可信区间 [CI]，21.2-86.3）和 44.4%（95% CI，13.7-78.8）。两种 IGRAs 检测 LTBI 危险因素的敏感性分别为 33.3%（95% CI，19.6-49.5）。T-SPOT.TB 的特异性为 85.5%（95% CI，78.9-90.7），QGIT 的特异性为 80.1%（95% CI，72.9-86.2）。联合使用 IGRAs 并不能显著提高敏感性。
由于它们在检测 RTR 中既往活动性结核病和可能的 LTBI 的敏感性非常低，因此 IGRAs 不能用于排除 LTBI。这些结果强调了 IGRAs 在慢性免疫抑制治疗背景下的局限性。
