Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Division of Infectious Diseases and Tropical Medicine, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
PLoS One. 2020 Nov 30;15(11):e0242598. doi: 10.1371/journal.pone.0242598. eCollection 2020.
Detection of IgA antibody against Mycobacterium avium complex (MAC) glycopeptidolipid (GPL) has recently been shown to improve the diagnosis of MAC pulmonary disease but has yet to be tested in disseminated Non-tuberculous mycobacteria (NTM) infection. In this study, we address the diagnostic efficacies of an anti-GPL-core ELISA kit in disseminated lymphadenopathy patients positive for NTM culture and anti-IFN-γ autoantibodies. The study was conducted in a tertiary referral center in northeastern Thailand and patients with NTM, tuberculosis, melioidosis, and control subjects were enrolled. Plasma immunoglobulin A (IgA) and G (IgG) antibodies against GPL-core were detected in the subjects and the specificity and sensitivity of the assay was assessed. Anti-GPL-core IgA and IgG levels were significantly higher in NTM patients than other groups (p < 0.0001). Diagnostic efficacy for NTM patients using anti-GPL-core IgA cut-off value of 0.352 U/ml showed good sensitivity (91.18%) and intermediate specificity (70.15%). Using a cut-off value of 4.140 AU/ml for anti-GPL-core IgG showed the same sensitivity (91.18%) with increased specificity (89.55%) and an 81.58% positive predictive value. Most patients with moderate levels (4.140-7.955 AU/ml) of anti-GPL-core IgG had rapidly growing mycobacteria (RGM) infection. Taken together, the detection of anti-GPL-core antibodies could provide a novel option for the diagnosis and management of disseminated NTM infected patients.
最近的研究表明，检测针对鸟分枝杆菌复合群（MAC）糖脂（GPL）的 IgA 抗体可提高 MAC 肺疾病的诊断，但尚未在播散性非结核分枝杆菌（NTM）感染中进行测试。在这项研究中，我们评估了一种抗-GPL 核心 ELISA 试剂盒在 NTM 培养和抗 IFN-γ 自身抗体阳性的播散性淋巴结病患者中的诊断效果。该研究在泰国东北部的一家三级转诊中心进行，纳入了 NTM、结核、类鼻疽和对照患者。检测了患者血浆中针对 GPL 核心的免疫球蛋白 A（IgA）和 G（IgG）抗体，并评估了该检测的特异性和敏感性。与其他组相比，NTM 患者的抗-GPL 核心 IgA 和 IgG 水平显著更高（p < 0.0001）。使用抗-GPL 核心 IgA 截断值为 0.352 U/ml 对 NTM 患者进行诊断的效能显示出良好的敏感性（91.18%）和中等特异性（70.15%）。使用抗-GPL 核心 IgG 的截断值 4.140 AU/ml 具有相同的敏感性（91.18%），但特异性更高（89.55%），阳性预测值为 81.58%。大多数抗-GPL 核心 IgG 中度水平（4.140-7.955 AU/ml）的患者都存在快速生长分枝杆菌（RGM）感染。综上所述，抗-GPL 核心抗体的检测可为诊断和管理播散性 NTM 感染患者提供一种新的选择。
