Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Department of Microbiology, All India Institute of Medical Sciences (AIIMS) Bilaspur, Himachal Pradesh, India.
Ocul Immunol Inflamm. 2023 Jul;31(5):914-920. doi: 10.1080/09273948.2022.2064880. Epub 2022 Apr 20.
Xpert MTB/RIF Ultra (Ultra) was evaluated for the first time on Ocular tuberculosis (OTB) samples and compared with Xpert.
Seventy five vitreous fluid samples (3 confirmed OTB, 47 clinically suspected OTB, and 25 controls) were subjected to Ultra, Xpert and Multiplex-PCR and compared against culture, composite reference standard (CRS), and gene sequencing.
The sensitivity of Ultra was 50% in diagnosing OTB (100% against culture and 46.8% against CRS). The overall sensitivity of Xpert and MPCR was 16% and 72%, respectively. Xpert missed three culture-positive cases and MPCR detected additional 11. Ultra and Xpert missed two and four cases of RifR, respectively. A total of 13(59%) cases were reported 'trace' by Ultra in which RifR could not be evaluated.
Ultra outperformed Xpert in diagnosing OTB. The advantage of Ultra's simultaneous RifR detection is lost since the trace bacterial loads in the specimens cause indeterminate results of RifR testing. OTB: Ocular tuberculosis; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF, MPCR: multiplex polymerase chain reaction; NAATs: Nucleic acid amplification tests; MLAMP: multitargeted loop-mediated isothermal amplification; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.
Xpert MTB/RIF Ultra（Ultra）首次用于眼部结核（OTB）样本的评估，并与 Xpert 进行了比较。
75 份玻璃体液样本（3 份确诊的 OTB、47 份临床疑似 OTB 和 25 份对照）接受了 Ultra、Xpert 和多重 PCR 检测，并与培养物、综合参考标准（CRS）和基因测序进行了比较。
Ultra 诊断 OTB 的敏感性为 50%（100%对培养物和 46.8%对 CRS）。Xpert 和 MPCR 的总敏感性分别为 16%和 72%。Xpert 漏诊了 3 例培养阳性病例，MPCR 检测到了另外 11 例。Ultra 和 Xpert 分别漏诊了 2 例和 4 例 RifR。共有 13 例（59%）Ultra 报告为“痕量”，无法评估 RifR。
Ultra 在诊断 OTB 方面优于 Xpert。Ultra 同时检测 RifR 的优势丧失，因为标本中痕量的细菌负荷导致 RifR 检测结果不确定。OTB：眼部结核；Ultra：Xpert MTB/RIF Ultra；Xpert：Xpert MTB/RIF，MPCR：多重聚合酶链反应；NAATs：核酸扩增试验；MLAMP：多靶向环介导等温扩增；PPV：阳性预测值；NPV：阴性预测值；EPTB：肺外结核病；VF：玻璃体；DNA：脱氧核糖核酸；ATT：抗结核治疗；RifR：利福平耐药；RifS：利福平敏感；RifI：利福平不确定。
