Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru.
PLoS One. 2012;7(9):e44626. doi: 10.1371/journal.pone.0044626. Epub 2012 Sep 7.
Diagnosis of pulmonary tuberculosis (TB) among human immunodeficiency virus (HIV) patients remains complex and demands easy to perform and accurate tests. Xpert®MTB/RIF (MTB/RIF) is a molecular TB diagnostic test which is rapid and convenient; the test requires minimal human resources and reports results within two hours. The majority of performance studies of MTB/RIF have been performed in high HIV burden settings, thus TB diagnostic studies among HIV patients in low HIV prevalence settings such as Peru are still needed.
METHODOLOGY/PRINCIPAL FINDINGS: From April 2010 to May 2011, HIV-positive patients with high clinical suspicion of TB were enrolled from two tertiary hospitals in Lima, Peru. Detection of TB by MTB/RIF was compared to a composite reference standard Löwenstein-Jensen (LJ) and liquid culture. Detection of rifampicin resistance was compared to the LJ proportion method. We included 131 patients, the median CD4 cell count was 154.5 cells/mm(3) and 45 (34.4%) had TB. For TB detection among HIV patients, sensitivity of MTB/RIF was 97.8% (95% CI 88.4-99.6) (44/45); specificity was 97.7% (95% CI 91.9-99.4) (84/86); the positive predictive value was 95.7% (95% CI 85.5-98.8) (44/46); and the negative predictive value, 98.8% (95% CI 93.6-99.8) (84/85). MTB/RIF detected 13/14 smear-negative TB cases, outperforming smear microscopy [97.8% (44/45) vs. 68.9% (31/45); p = 0.0002]. For rifampicin resistance detection, sensitivity of MTB/RIF was 100% (95% CI 61.0-100.0) (6/6); specificity was 91.0% (95% CI 76.4-96.9) (30/33); the positive predictive value was 66.7% (95% CI 35.4-87.9) (6/9); and the negative predictive value was 100% (95% CI 88.7 -100.0) (30/30).
CONCLUSIONS/SIGNIFICANCE: In HIV patients in our population with a high clinical suspicion of TB, MTB/RIF performed well for TB diagnosis and outperformed smear microscopy.
在人类免疫缺陷病毒（HIV）患者中，肺结核（TB）的诊断仍然很复杂，需要易于操作且准确的检测方法。Xpert®MTB/RIF（MTB/RIF）是一种快速便捷的分子结核病诊断检测方法，所需人力资源最少，可在两小时内报告结果。大多数 MTB/RIF 的性能研究都是在 HIV 负担较重的环境中进行的，因此，秘鲁等 HIV 流行率较低地区的 HIV 患者的 TB 诊断研究仍然需要进行。
方法/主要发现：从 2010 年 4 月到 2011 年 5 月，从秘鲁利马的两家三级医院招募了具有高度临床疑似结核病的 HIV 阳性患者。MTB/RIF 对结核病的检测结果与复合参考标准 Löwenstein-Jensen（LJ）和液体培养进行了比较。利福平耐药性的检测结果与 LJ 比例法进行了比较。我们共纳入了 131 名患者，中位 CD4 细胞计数为 154.5 个细胞/mm³，其中 45 人（34.4%）患有结核病。对于 HIV 患者的结核病检测，MTB/RIF 的敏感性为 97.8%（95%CI 88.4-99.6）（44/45）；特异性为 97.7%（95%CI 91.9-99.4）（84/86）；阳性预测值为 95.7%（95%CI 85.5-98.8）（44/46）；阴性预测值为 98.8%（95%CI 93.6-99.8）（84/85）。MTB/RIF 检测到 13/14 例涂片阴性结核病病例，优于涂片显微镜检查[97.8%（44/45）与 68.9%（31/45）；p=0.0002]。对于利福平耐药性检测，MTB/RIF 的敏感性为 100%（95%CI 61.0-100.0）（6/6）；特异性为 91.0%（95%CI 76.4-96.9）（30/33）；阳性预测值为 66.7%（95%CI 35.4-87.9）（6/9）；阴性预测值为 100%（95%CI 88.7-100.0）（30/30）。
结论/意义：在我们的人群中，对结核病有高度临床疑似的 HIV 患者中，MTB/RIF 对结核病诊断的表现良好，优于涂片显微镜检查。
