Department of Orthopedics, Beijing Tuberculosis and Thoracic Tumor Institute, Beijing, China.
Department of General Medicine, Beijing Tuberculosis and Thoracic Tumor Institute, Beijing, China.
PLoS One. 2018 Jun 1;13(6):e0198600. doi: 10.1371/journal.pone.0198600. eCollection 2018.
Both osteoarticular tuberculosis (OA-TB) and inflammatory arthritis can lead to osteoarticular structural damage. These conditions exhibit similar symptoms, physical signs, and imaging features. Rapidly and accurately diagnosing OA-TB in patients with inflammatory arthritis presents a challenge to clinicians. Xpert MTB/RIF (Xpert) has been endorsed by the World Health Organization (WHO) as a rapid diagnostic tool for diagnosis of pulmonary and extrapulmonary TB. This study was designed to investigate diagnostic efficiency of Xpert for OA-TB in patients with inflammatory arthritis in China.
A total of 83 consecutive patients with inflammatory arthritis and suspected OA-TB were enrolled prospectively from June 2014 to May 2018. Demographic, clinical, and biological data were recorded. Xpert assay, smear microscopy examination (smear), BACTEC MGIT 960 (MGIT 960), pathological examination, and T-SPOT.TB test were performed for each patient who received operations. Diagnostic efficiency of Xpert was evaluated based on a composite reference standard (CRS).
A total of 49 out of 83 patients with inflammatory arthritis and suspected OA-TB received operations, and 49 specimens were obtained during operations. According to CRS, 36 out of 49 patients with inflammatory arthritis were diagnosed with OA-TB, and 13 were not affected by the condition. Sensitivity of Xpert assay, smear, MGIT 960, pathological examination, and T-SPOT.TB test reached 66.70% (24/36), 25.00% (9/36), 30.55% (11/36), 47.22% (17/36), and 80.55% (29/36), respectively. Specificity of Xpert assay, smear, MGIT 960, and pathological examination was all 100% (13/13). Specificity of T-SPOT.TB test was 53.84% (7/13). Sensitivity of Xpert was higher than that of smear, MGIT 960 and pathological examination, but the sensitivity of Xpert was lower than that of T-SPOT.TB. Sensitivity of Xpert was statistically different from that of smear and MGIT 960 (P<0.001, P = 0.002), but the sensitivity of Xpert was not significantly different from that of pathological examination and T-SPOT.TB (P = 0.096, P = 0.181). Specificity of T-SPOT.TB was less than that of Xpert, smear, MGIT 960, and pathological examination, and the difference between them was statistically significant (P = 0.015). Among the 27 OA-TB patients with smear negative results, Xpert had the highest sensitivity, but sensitivity of Xpert was not significantly different from that of pathological examination and T-SPOT.TB (P = 0.413, P = 0.783). 2 of 36 OA-TB patients exhibited RIF resistance. Xpert was concordant with MGIT 960-based drug susceptibility testing (DST) in detecting rifampin (RIF) resistance.
Xpert is an efficient tool with high sensitivity and specificity for OA-TB diagnosis in patients with inflammatory arthritis in high-TB prevalence countries. Compared with conventional methods, Xpert has two advantages: one is fast, and the other is able to provide RIF resistance information simultaneously.
骨关节炎性结核（OA-TB）和炎症性关节炎均可导致骨关节结构损伤。这些疾病具有相似的症状、体征和影像学特征。对于临床医生来说，快速准确地诊断炎症性关节炎患者的 OA-TB 具有挑战性。Xpert MTB/RIF（Xpert）已被世界卫生组织（WHO）认可为诊断肺和肺外 TB 的快速诊断工具。本研究旨在探讨 Xpert 在我国炎症性关节炎患者中诊断 OA-TB 的诊断效率。
2014 年 6 月至 2018 年 5 月，前瞻性纳入 83 例疑似 OA-TB 的炎症性关节炎患者。记录患者的人口统计学、临床和生物学数据。对每位接受手术的患者进行 Xpert 检测、涂片显微镜检查（涂片）、BACTEC MGIT 960（MGIT 960）、病理检查和 T-SPOT.TB 检测。根据综合参考标准（CRS）评估 Xpert 的诊断效率。
83 例疑似 OA-TB 的炎症性关节炎患者中，共 49 例接受了手术，手术期间共获得 49 份标本。根据 CRS，49 例炎症性关节炎患者中 36 例诊断为 OA-TB，13 例未受影响。Xpert 检测、涂片、MGIT 960、病理检查和 T-SPOT.TB 检测的灵敏度分别为 66.70%（24/36）、25.00%（9/36）、30.55%（11/36）、47.22%（17/36）和 80.55%（29/36）。Xpert 检测、涂片、MGIT 960 和病理检查的特异性均为 100%（13/13）。T-SPOT.TB 检测的特异性为 53.84%（7/13）。Xpert 的灵敏度高于涂片、MGIT 960 和病理检查，但 Xpert 的灵敏度低于 T-SPOT.TB。Xpert 的灵敏度与涂片和 MGIT 960 有统计学差异（P<0.001，P=0.002），但与病理检查和 T-SPOT.TB 无统计学差异（P=0.096，P=0.181）。T-SPOT.TB 的特异性低于 Xpert、涂片、MGIT 960 和病理检查，差异具有统计学意义（P=0.015）。在 27 例涂片阴性的 OA-TB 患者中，Xpert 的灵敏度最高，但 Xpert 的灵敏度与病理检查和 T-SPOT.TB 无统计学差异（P=0.413，P=0.783）。36 例 OA-TB 患者中有 2 例存在 RIF 耐药。Xpert 与基于 MGIT 960 的药物敏感性试验（DST）在检测利福平（RIF）耐药方面具有一致性。
在高结核流行国家，Xpert 是一种高效、高灵敏度和特异性的诊断炎症性关节炎患者 OA-TB 的工具。与常规方法相比，Xpert 具有两个优势：一是快速，二是能够同时提供 RIF 耐药信息。
