Department of Epidemiology, University of North Carolina at Chapel Hill, 2104F McGavran Greenberg Hall, Chapel Hill, NC, 27514-7435, USA,
Eur J Clin Microbiol Infect Dis. 2013 Nov;32(11):1409-15. doi: 10.1007/s10096-013-1890-0. Epub 2013 May 10.
Xpert MTB/RIF (Xpert) is recommended for human immunodeficiency virus (HIV)-associated pulmonary tuberculosis but not extrapulmonary tuberculosis. We assessed the performance of Xpert for HIV-associated lymph node tuberculosis (LNTB), the most common type of extrapulmonary tuberculosis. Among HIV-infected adults suspected of LNTB presenting for fine needle aspirate (FNA) at a South African hospital, we assessed the diagnostic accuracy of Xpert using either FNA culture or a composite of microscopy, culture, and cytology as the reference standard, and evaluated the impact of different diagnostics on patient management. Among 344 adults with valid FNA culture and Xpert results, 84 (24 %) were positive on microscopy, 149 (43 %) on culture, 152 (53 %) on Xpert, and 181 (57 %) had a cytology result suggestive of tuberculosis. Using liquid culture as the reference standard, the specificity of a single Xpert was suboptimal (88.2 %) but the sensitivity was high [93.3 %, 95 % confidence interval (CI) 87.6-96.6] and increased with decreasing CD4 count (from 87.0 % for CD4 >250 to 98.6 % for CD4 <100 cells/mm(3)). Using a composite reference standard reduced the sensitivity to 79.2 % but increased the specificity to 98.6 %. All Xpert-positive patients initiated treatment within one day, compared to 70 % of culture-positive but Xpert-negative and 13 % of culture- and Xpert-negative but cytology-positive patients. Xpert is accurate and effective and could be endorsed as the initial diagnostic for HIV-associated LNTB.
Xpert MTB/RIF（Xpert）推荐用于人类免疫缺陷病毒（HIV）相关的肺结核，但不推荐用于肺外结核。我们评估了 Xpert 对 HIV 相关淋巴结结核（LNTB）的性能，LNTB 是最常见的肺外结核类型。在南非一家医院就诊、疑似 LNTB 并进行细针抽吸（FNA）的 HIV 感染成年人中，我们评估了 Xpert 的诊断准确性，以 FNA 培养或显微镜检查、培养和细胞学的组合作为参考标准，并评估了不同诊断方法对患者管理的影响。在 344 例有有效 FNA 培养和 Xpert 结果的成年人中，84 例（24%）显微镜检查阳性，149 例（43%）培养阳性，152 例（53%）Xpert 阳性，181 例（57%）细胞学结果提示结核。使用液体培养作为参考标准，单次 Xpert 的特异性不理想（88.2%），但灵敏度较高[93.3%，95%置信区间（CI）87.6-96.6]，且随 CD4 计数的降低而增加（从 CD4>250 的 87.0%增加到 CD4<100 个/mm3 的 98.6%）。使用复合参考标准可将灵敏度降低至 79.2%，但特异性提高至 98.6%。所有 Xpert 阳性患者在一天内开始治疗，而培养阳性但 Xpert 阴性的患者为 70%，培养和 Xpert 阴性但细胞学阳性的患者为 13%。Xpert 准确有效，可以作为 HIV 相关 LNTB 的初始诊断方法。
