Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dongcheng-qu, Beijing, China.
State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Dongcheng-qu, Beijing, China.
Ann Rheum Dis. 2021 Jun;80(6):739-747. doi: 10.1136/annrheumdis-2020-218460. Epub 2021 Jan 15.
Lack of effective biomarkers in anti-citrullinated protein antibody (ACPA)-negative rheumatoid arthritis (RA) impedes early diagnosis and treatment. This study aimed to identify novel autoantibodies in RA and verify their diagnostic values in ACPA-negative RA based on protein microarray technology.
A total of 1011 sera from 559 RA (276 ACPA-positive and 283 ACPA-negative), 239 disease controls (DCs) and 213 healthy controls (HCs) were collected and sampled on two sequential microarrays and ELISA and western blot (WB) detection, for novel autoantibodies discovery, validation and verification, respectively. The high-density protein microarray printed with a broad spectrum of recombinant human proteins was first employed to screen candidate autoantibodies, then focused microarrays composed of candidate autoantigens were used for validation, followed by ELISA and WB to verify the presence of the most promising candidates in ACPA-negative RA.
Nine novel autoantibodies were identified by two sequential microarrays with positivity 17.93%-27.59% and specificities >90% in ACPA-negative RA. Among these, anti-PTX3 and anti-DUSP11 autoantibodies presented with the highest sensitivity and were consistently verified by ELISA and WB. Pooling samples of all cohorts, the positivities of anti-PTX3 and anti-DUSP11 in ACPA-negative RA were 27.56% and 31.80%, respectively, similar to those in ACPA-positive RA, and significantly higher than in HCs (4.69% and 2.35%) and DCs (10.04% and 8.49%) (p<0.0001). Combination of anti-PTX3 with anti-DUSP11 significantly increased the diagnostic sensitivity (38.00%) with specificity of 88.72%, regardless of ACPA status.
Anti-PTX3 and anti-DUSP11 autoantibodies are newly identified biomarkers for diagnosis of ACPA-negative RA.
抗瓜氨酸化蛋白抗体（ACPA）阴性类风湿关节炎（RA）缺乏有效的生物标志物，阻碍了早期诊断和治疗。本研究旨在基于蛋白质微阵列技术，发现 RA 中的新型自身抗体，并验证其在 ACPA 阴性 RA 中的诊断价值。
共收集了 559 例 RA（276 例 ACPA 阳性和 283 例 ACPA 阴性）、239 例疾病对照（DC）和 213 例健康对照（HC）的 1011 份血清，分别在两个连续的微阵列和 ELISA、western blot（WB）检测中进行检测，以进行新型自身抗体的发现、验证和验证。首先使用带有广谱重组人蛋白的高密度蛋白质微阵列筛选候选自身抗体，然后使用由候选自身抗原组成的聚焦微阵列进行验证，最后使用 ELISA 和 WB 验证 ACPA 阴性 RA 中最有希望的候选物的存在。
通过两个连续的微阵列共鉴定了 9 种新型自身抗体，在 ACPA 阴性 RA 中的阳性率为 17.93%-27.59%，特异性>90%。其中，抗 PTX3 和抗 DUSP11 自身抗体的敏感性最高，并且通过 ELISA 和 WB 得到了一致的验证。在所有队列的样本中，抗 PTX3 和抗 DUSP11 在 ACPA 阴性 RA 中的阳性率分别为 27.56%和 31.80%，与 ACPA 阳性 RA 相似，明显高于 HC（4.69%和 2.35%）和 DC（10.04%和 8.49%）（p<0.0001）。抗 PTX3 与抗 DUSP11 的联合显著提高了诊断敏感性（38.00%），特异性为 88.72%，与 ACPA 状态无关。
抗 PTX3 和抗 DUSP11 自身抗体是新发现的诊断 ACPA 阴性 RA 的生物标志物。
