The Value of Rheumatoid Arthritis Citrullinated Peptides (RACP) System in the Diagnosis of Rheumatoid Arthritis: A Retrospective Analysis of 2632 Patients

IF 2 4区医学 Q2 RHEUMATOLOGY

International Journal of Rheumatic Diseases Pub Date : 2025-08-13 DOI:10.1111/1756-185x.70393

Kun Yang, Sixing Li, Leting Zheng, Fei Dong, Jing Wen, Zhendong He, Jiale Wen, Fang Qin

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Abstract

Objectives and Aim

This study aimed to evaluate the diagnostic accuracy and prognostic value of the Rheumatoid Arthritis Citrullinated Peptides (RACP) assay in a real-world cohort, assessing its performance both independently and in combination with established biomarkers such as anti-cyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), and anti-keratin antibodies (AKA).

Methods

A single-center retrospective analysis included 2632 patients who underwent serological testing between September 2022 and September 2023. Of these, 644 patients met ACR/EULAR classification criteria for rheumatoid arthritis (RA), while 1988 patients served as non-RA controls, including an osteoarthritis (OA) subgroup. RACP, anti-CCP, RF, and AKA levels were measured by enzyme-linked immunosorbent assay (ELISA). Diagnostic sensitivity, specificity, and combination strategies were assessed using chi-square and t-tests.

Results

RACP alone demonstrated a sensitivity of 76.86% and a specificity of 89.94%, closely comparable to anti-CCP (70.87% sensitivity and 89.92% specificity). Area under the curve (AUC) values were 0.805 for RACP, 0.783 for RF, 0.799 for anti-CCP, and 0.623 for AKA. Combining RACP with RF improved sensitivity (85.36%), while dual positivity (RACP + AKA) optimized specificity (96.61%). In the OA subgroup, biomarker positivity remained minimal, confirming strong discriminatory capacity. Patients positive for RACP or anti-CCP exhibited significantly higher tender joint counts, correlating biomarker positivity with clinical disease severity.

Conclusion

RACP is a robust biomarker for RA diagnosis, offering sensitivity and specificity comparable to or exceeding traditional assays. Combinations with RF or anti-CCP enhance diagnostic accuracy, supporting its utility in early RA detection, differential diagnosis from OA, and potentially reflecting disease activity. Prospective studies are warranted to confirm these findings.

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类风湿关节炎瓜氨酸肽（RACP）系统在2632例类风湿关节炎诊断中的价值

目的和目的本研究旨在评估类风湿性关节炎瓜氨酸肽（RACP）检测在现实世界队列中的诊断准确性和预后价值，评估其独立和与已建立的生物标志物(如抗环瓜氨酸肽（anti-CCP）、类风湿因子（RF）和抗角蛋白抗体（AKA）联合的性能。方法采用单中心回顾性分析，纳入2022年9月至2023年9月期间接受血清学检测的2632例患者。其中，644例患者符合类风湿关节炎（RA）的ACR/EULAR分类标准，而1988例患者作为非RA对照，包括骨关节炎（OA）亚组。采用酶联免疫吸附试验（ELISA）测定RACP、anti-CCP、RF和AKA水平。采用卡方检验和t检验评估诊断敏感性、特异性和联合策略。结果单独使用RACP的敏感性为76.86%，特异性为89.94%，与抗ccp（敏感性70.87%，特异性89.92%）相当。RACP的曲线下面积（AUC）为0.805，RF为0.783，anti-CCP为0.799，AKA为0.623。RACP联合RF可提高灵敏度（85.36%），双阳性（RACP + AKA）可优化特异性（96.61%）。在OA亚组中，生物标志物阳性仍然很低，证实了很强的歧视能力。RACP或anti-CCP阳性的患者表现出明显较高的压痛关节计数，生物标志物阳性与临床疾病严重程度相关。结论RACP是一种可靠的RA诊断生物标志物，其灵敏度和特异性可与传统检测相媲美或超过传统检测。与RF或抗ccp联合使用可提高诊断准确性，支持其在早期RA检测、OA鉴别诊断和潜在反映疾病活动性方面的应用。有必要进行前瞻性研究来证实这些发现。

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

International Journal of Rheumatic Diseases RHEUMATOLOGY-

CiteScore

3.70

自引率

4.00%

发文量

362

审稿时长

1 months

期刊介绍： The International Journal of Rheumatic Diseases (formerly APLAR Journal of Rheumatology) is the official journal of the Asia Pacific League of Associations for Rheumatology. The Journal accepts original articles on clinical or experimental research pertinent to the rheumatic diseases, work on connective tissue diseases and other immune and allergic disorders. The acceptance criteria for all papers are the quality and originality of the research and its significance to our readership. Except where otherwise stated, manuscripts are peer reviewed by two anonymous reviewers and the Editor.