Immunology Medical Strategy, Bristol-Myers Squibb K.K., Shinjuku, Tokyo, Japan.
Research and Early Development, BrightPath Biotherapeutics Co., Ltd., Kawasaki, Kanagawa, Japan.
Clin Exp Rheumatol. 2022 May;40(5):936-944. doi: 10.55563/clinexprheumatol/ucnzun. Epub 2021 Jul 8.
The importance of citrullination in rheumatoid arthritis (RA) has been reported, but the degree to which individual citrullinated proteins affect the onset and progression of RA is still unclear. We aimed to identify citrullinated proteins that may play an important role in the onset and progression of RA using an individualised anti-citrullinated protein antibody (ACPA) evaluation system with citrullinated peptides as probes.
Serum samples from 50 normal donors and 51 RA patients were evaluated using a custom MagPlexTM bead array with 13 types of citrullinated peptide. The presence/absence of ACPAs that react to each citrullinated peptide in each subject was determined using the Z-score, which was calculated based on the fluorescence intensity distribution of a sample from a normal donor. Whether the fluorescence intensity was inhibited when free citrullinated peptides were added to a system was also evaluated.
Median fluorescence intensities obtained from beads coupled with the 13 types of citrullinated peptide were all significantly higher in RA patients versus normal donors. With a Z-score ≥2 as the cut-off value for the presence of ACPAs, ACPAs that recognised five types of citrullinated peptides derived from fibrinogen A, fillagrin, clusterin, and vimentin were widely detected in RA patients. In addition, inhibition experiments showed that citrullinated vimentin, clusterin, and enolase 1A peptides inhibited coupling of ACPAs to other citrullinated peptides.
ACPAs to many citrullinated proteins exhibited cross-reactivity to citrullinated clusterin and vimentin, suggesting the importance of citrullinated clusterin and vimentin in the early stages of RA pathogenesis.
已报道瓜氨酸化在类风湿关节炎（RA）中的重要性，但个体瓜氨酸化蛋白对 RA 发病和进展的影响程度仍不清楚。我们旨在使用以瓜氨酸化肽作为探针的个体化抗瓜氨酸化蛋白抗体（ACPA）评估系统来鉴定可能在 RA 发病和进展中起重要作用的瓜氨酸化蛋白。
使用带有 13 种瓜氨酸化肽的定制 MagPlexTM 珠微阵列评估 50 名正常供体和 51 名 RA 患者的血清样本。使用基于正常供体样本荧光强度分布计算的 Z 分数确定每个个体对每种瓜氨酸化肽的 ACPA 的存在/缺失。还评估了在添加游离瓜氨酸化肽时系统中荧光强度是否受到抑制。
与正常供体相比，与 13 种瓜氨酸化肽偶联的珠的中位荧光强度均显著更高。当以 Z 分数≥2 作为存在 ACPA 的截断值时，广泛检测到针对源自纤维蛋白原 A、filaggrin、clusterin 和波形蛋白的五种瓜氨酸化肽的 ACPA。此外，抑制实验表明瓜氨酸化波形蛋白、clusterin 和烯醇化酶 1A 肽抑制 ACPA 与其他瓜氨酸化肽的偶联。
许多瓜氨酸化蛋白的 ACPA 对瓜氨酸化 clusterin 和波形蛋白表现出交叉反应性，表明瓜氨酸化 clusterin 和波形蛋白在 RA 发病机制的早期阶段很重要。
