BACKGROUND Serum anti-glycopeptidolipid (GPL) core immunoglobuin A (IgA) antibody test has been proposed as a diagnostic tool for Mycobacterium avium complex pulmonary diseases. Cross-reactivity with other non-tuberculous mycobacteria (NTM), including M. abscessus, indicates that it may have a role as a broader screening test for NTM pulmonary disease (NTM-PD). NTM-PD is believed to be underdiagnosed in patients with bronchiectasis. RESEARCH QUESTION Can the serum anti-GPL core IgA antibody test be used to screen for NTM-PD in bronchiectasis? STUDY DESIGN AND METHODS Patients from the prospective European Bronchiectasis Registry (EMBARC-BRIDGE; NCT03791086) were enrolled. Patients from the United Kingdom, Italy, Spain, Belgium, the Netherlands, and Germany were included. A control cohort of patients without any underlying lung disease was also recruited. The levels of serum IgA antibodies against the GPL core were measured using an enzyme immunoassay kit, and receiver operating characteristics curve analysis was conducted to evaluate the accuracy of the antibody level in screening for NTM-PD. RESULTS 282 patients were enrolled (151 [53.6%] female, median age 68 years). Median (quartile 1-3) anti-GPL-core IgA antibody levels were 0.2 (0.1-0.3) U/mL in patients without NTM isolation and NTM-PD (n=238), 0.3 (0.2-0.4) U/mL in NTM isolation that were incompatible with the diagnosis of NTM-PD (n=18) and 1.5 (0.4-6.2) U/mL in NTM-PD (n=26) (P=0.0001). Antibody levels showed excellent accuracy in identifying patients with NTM-PD (area under the curve 0.886, 95% CI 0.800-0.973) in bronchiectasis cohort and also showed excellent discrimination of patients with NTM-PD from those with NTM isolation who did not meet the diagnostic criteria for NTM-PD (0.816, 95% CI 0.687-0.945). INTERPRETATION The anti-GPL-core IgA antibody demonstrated excellent efficacy in screening for NTM-PD in a large bronchiectasis cohort.

中文翻译：

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血清抗糖肽脂核心 IgA 抗体检测筛查支气管扩张症非结核分枝杆菌肺病的临床疗效：一项欧洲多中心队列研究。


背景 血清抗糖肽脂 （GPL） 核心免疫球蛋白 A （IgA） 抗体检测已被提议作为鸟分枝杆菌复杂肺部疾病的诊断工具。与其他非结核分枝杆菌 （NTM） 的交叉反应性，包括脓肿分枝杆菌，表明它可能作为 NTM 肺病 （NTM-PD） 的更广泛筛查试验。据信，支气管扩张症患者的 NTM-PD 诊断不足。研究问题 血清抗 GPL 核心 IgA 抗体检测可用于筛查支气管扩张症中的 NTM-PD 吗？研究设计和方法 来自前瞻性欧洲支气管扩张登记处 （EMBARC-BRIDGE;NCT03791086） 被纳入。包括来自英国、意大利、西班牙、比利时、荷兰和德国的患者。还招募了没有任何潜在肺部疾病的患者对照组。使用酶免疫测定试剂盒测量针对 GPL 核心的血清 IgA 抗体水平，并进行受试者工作特征曲线分析以评估抗体水平筛查 NTM-PD 的准确性。结果 共纳入 282 例患者 （151 [53.6%] 女性，中位年龄 68 岁）。未分离 NTM 的患者中位 （4/4） 1-3 抗 GPL 核心 IgA 抗体水平为 0.2 （0.1-0.3） U/mL，与诊断不符的 NTM-PD （n=238） 和 0.3 （0.2-0.4） U/mL，NTM-PD （n=26） 为 1.5 （0.4-6.2） U/mL（P=0.0001）。抗体水平在支气管扩张队列中识别 NTM-PD 患者 （曲线下面积 0.886,95% CI 0.800-0.973） 表现出极好的准确性，并且还显示出对 NTM-PD 患者与不符合 NTM-PD 诊断标准的 NTM 隔离患者 （0.816， 95% CI 0.687-0.945） 的良好区分。 解释 抗 GPL 核心 IgA 抗体在大型支气管扩张队列中筛查 NTM-PD 方面表现出优异的疗效。