Improved Detection of Myositis-Specific Autoantibodies Using Luciferase Immunoprecipitation Systems Assay: Comparison With Line Blot and Conventional Immunoprecipitation

IF 9.9 1区医学 Q1 RHEUMATOLOGY

Arthritis & Rheumatology Pub Date : 2026-08-25 Epub Date: 2026-03-31 DOI:10.1002/art.70103

Peter D. Burbelo PhD, Iago Pinal-Fernandez MD, PhD, Maria Casal-Dominguez MD, PhD, Xin Tian PhD, Shijinqiu Gao MS, Neha Gupta BS, Eric W. Robbins MD, John A. Chiorini PhD, Christopher A. Mecoli MD, MHS, Lisa Christopher-Stine MD, MPH, Livia Casciola-Rosen PhD, Andrew L. Mammen MD, PhD, Sonye K. Danoff MD, PhD, Anthony F. Suffredini MD, Julio A. Huapaya MD, MHS

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引用次数: 0

Abstract

Objective

Myositis-specific autoantibodies guide the diagnosis and classification of idiopathic inflammatory myopathies, but current immunoassays vary in accuracy, particularly for autoantibodies associated with interstitial lung disease. To compare the performance of the luciferase immunoprecipitation systems (LIPS) assay with line blot and immunoprecipitation (IP) and to evaluate whether antibody-specific thresholds modify line blot concordance.

Methods

We analyzed 279 sera with line blot results from the Johns Hopkins Myositis Center. LIPS was performed for anti–Jo-1, anti–PL-7, anti–PL-12, anti–MDA-5, anti-EJ, and anti-Ro52 autoantibodies. Line blot results were evaluated using standard thresholds (≥36 and ≥71 arbitrary units [AU]). Assay performance was evaluated against IP (n = 141). In patients without IP (n = 138), clinical diagnoses were examined.

Results

LIPS showed excellent agreement with IP (κ = 0.90, area under the receiver operating characteristic curve 0.935), outperforming line blot. Line blot cutoffs influenced performance: ≥36 AU increased sensitivity (92.9%) but reduced specificity (73.8%), whereas ≥71 AU improved specificity (92.9%) but lowered sensitivity (82.8%). Antibody-specific thresholds modified concordance but remained quantitatively inferior to LIPS. In patients without IP, concordance between LIPS and line blot was 89% at ≥36 AU and 83% at ≥71 AU. LIPS-positive cases were enriched for antisynthetase syndrome and dermatomyositis. Among discordant cases (line blot positive and LIPS negative), most were clinically classified as inclusion body myositis (5 of 11). For anti-Ro52, discrepancies were most frequent at titers <36 AU.

Conclusion

LIPS provides quantitative discrimination, strong concordance with IP, and improved performance compared with line blot, particularly at low to intermediate titers. By reducing misclassification and complementing antibody-specific thresholds, LIPS has the potential to enhance clinical stratification in patients with myositis.

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荧光素酶免疫沉淀系统检测肌炎特异性自身抗体的改进：与线印迹和常规免疫沉淀的比较。

背景：肌炎特异性自身抗体指导特发性炎性肌病的诊断和分类，但目前的免疫测定在准确性方面存在差异，特别是与间质性肺疾病相关的自身抗体。目的：比较荧光素酶免疫沉淀系统（LIPS）与免疫印迹法（line blot）和免疫沉淀法（immunoprecipitation， IP）的性能，并评价抗体特异性阈值是否改变了荧光素酶免疫印迹法的一致性。方法：我们分析了来自约翰霍普金斯大学肌炎中心的279份血清。lip检测抗jo -1、抗pl -7、抗pl -12、抗mda -5、抗ej和抗ro52自身抗体。采用标准阈值（≥36，≥71任意单位[AU]）评估线印迹结果。用IP （n=141）评价检测性能。对无IP的患者（n=138）进行临床诊断检查。结果：lip与IP吻合良好（κ=0.90, AUC 0.935），优于line blot。线印迹临界值影响检测效果：≥36 AU可提高灵敏度（92.9%），但降低特异性（73.8%），≥71 AU可提高特异性（92.9%），但降低敏感性（82.8%）。抗体特异性阈值改变了一致性，但在数量上仍逊于LIPS。在没有IP的患者中，≥36 AU时LIPS和line blot的一致性为89%，≥71 AU时为83%。lips阳性的病例多为抗合成酶综合征和皮肌炎。在不一致的病例（线印迹阳性/ lips阴性）中，大多数临床分类为包涵体肌炎（5/11）。对于抗ro52，在滴度上差异最常见。结论：LIPS提供了定量鉴别，与IP有很强的一致性，与line blot相比，性能更好，特别是在低到中滴度。通过减少误分类和补充抗体特异性阈值，LIPS有可能增强肌炎患者的临床分层。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Arthritis & Rheumatology RHEUMATOLOGY-

CiteScore

20.90

自引率

3.00%

发文量

371

期刊介绍： Arthritis & Rheumatology is the official journal of the American College of Rheumatology and focuses on the natural history, pathophysiology, treatment, and outcome of rheumatic diseases. It is a peer-reviewed publication that aims to provide the highest quality basic and clinical research in this field. The journal covers a wide range of investigative areas and also includes review articles, editorials, and educational material for researchers and clinicians. Being recognized as a leading research journal in rheumatology, Arthritis & Rheumatology serves the global community of rheumatology investigators and clinicians.