BACKGROUND Tubercular lymphadenitis (TBLA) is one of the most common extrapulmonary manifestations of tuberculosis in patients with HIV. With several other pathological conditions presenting as lymphadenitis and lack of consensus regarding a gold standard test, the diagnosis of TBLA remains a challenge for the clinician. OBJECTIVES and design: In this study, we have assessed the potential of loop-mediated isothermal amplification (LAMP) test for the diagnosis of TBLA in HIV-infected patients. The study group included samples collected by fine needle aspiration (FNAC) of lymph nodes from 24 HIV-infected patients with TBLA. A composite reference standard was used to identify cases of TBLA based on clinical suspicion, results of cytology, AFB smear, MGIT culture, GeneXpert MTB/RIF, multiplex polymerase chain reaction (MPCR) and subsequently clinical response to antitubercular therapy. These tests were also carried out in 26 control samples of lymph node FNAC from HIV-infected patients with non-tubercular lymphadenitis. RESULTS LAMP assay was positive in 19/24 TBLA cases and yielded a sensitivity of 79.17% with 100% specificity. Cytology was suggestive in 18/24 (75%) TBLA cases. GeneXpert MTB/RIF assay correctly identified 16/24 TBLA cases, but the test did show one false positive result reducing its specificity. MPCR had the highest sensitivity of 91.67% as it correctly identified 22/24 cases and showed no false positive result. CONCLUSION The current study highlights the potential of LAMP test for the specific diagnosis of tubercular lymphadenitis in FNAC samples from HIV-infected patients, especially when cytology is either non-conclusive or non-available. Though MPCR had a higher sensitivity than LAMP assay, the added advantages of low cost, minimal technical expertise and simplicity of procedure make LAMP assay a suitable diagnostic test in resource-limited settings.

中文翻译：

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环介导的等温扩增（LAMP）分析，GeneXpert MTB / Rif和多重PCR在印度北部感染HIV的患者中诊断结核性淋巴结炎的比较评估。

背景技术结核淋巴结炎（TBLA）是HIV患者中结核病最常见的肺外表现之一。由于其他几种病理状况表现为淋巴结炎，并且对金标准测试缺乏共识，TBLA的诊断仍然是临床医生面临的挑战。目的和设计：在这项研究中，我们评估了环介导的等温扩增（LAMP）试验在HIV感染患者中诊断TBLA的潜力。该研究组包括通过细针抽吸（FNAC）收集的24例HIV感染的TBLA患者的淋巴结样本。基于临床怀疑，细胞学检查结果，AFB涂片，MGIT培养，GeneXpert MTB / RIF，多重聚合酶链反应（MPCR），以及随后对抗结核治疗的临床反应。这些测试还对来自HIV感染的非结核性淋巴结炎患者的26例淋巴结FNAC对照样本进行了测试。结果LAMP检测在19/24 TBLA患者中呈阳性，灵敏度为79.17％，特异性为100％。细胞学检查提示18/24（75％）TBLA患者。GeneXpert MTB / RIF分析可正确识别16/24 TBLA病例，但该测试确实显示出一个假阳性结果，降低了其特异性。MPCR的最高灵敏度为91.67％，因为它可以正确识别22/24例病例，并且没有假阳性结果。结论当前的研究强调了LAMP检测在诊断HIV感染患者的FNAC样本中结核性淋巴结炎的特异性诊断中的潜力，特别是当细胞学检查不是结论性的或不可用时。尽管MPCR比LAMP分析具有更高的灵敏度，但低成本，技术专长最少和操作简便等优点使LAMP分析成为资源有限环境下的合适诊断测试。