Novel Serum Markers that Distinguish Behcet’s Disease from Idiopathic Recurrent Aphthous Stomatitis

Behcet’s disease (BD) is a rare and recurrent autoinflammatory disorder characterized by systemic vasculitis, frequently manifested as recurrent aphthous stomatitis (RAS). We aim to identify specific serum proteins to discriminate between BD and idiopathicRAS. Peripheral blood was collected from 12 BD patients, 12 idiopathic RAS patients, and 21 healthy volunteers. The serum samples underwent Tandem Mass Tag-based mass spectrometry analysis. Differentially expressed proteins (DEPs) were identified for KEGG pathway enrichment, Gene Ontology (GO), and protein-protein interaction (PPI) analyses. ELISA was utilized to verify two BD-specific DEPs in another cohort consisting of 18 BD patients, 18 idiopathic RAS patients, and 18 controls. Compared with RAS serum, BD serum showed 242 DEPs. 49 proteins were differentially expressed in BD but not RAS serum compared to healthy controls. KEGG pathway and GO analyses revealed that DEPs in BD and RAS have similar biological functions and cellular distributions, featuring a significant association with pathways regulating blood coagulation and immune response. When comparing DEPs between BD and RAS, several keratins emerged as markers that distinguish RAS from BD. We also identified multiple DEPs in BD but not RAS patients. PPI analysis uncovered that lipoprotein metabolism regulators serve as hub proteins, indicating their potentially essential roles in BD pathology. In addition, ELISA results confirmed the elevated LRG1 and SOD3 levels in BD, but not RAS patients, compared to healthy donors. Our data uncovered novel serum proteins that distinguish BD from RAS, which may potentially be useful in BD diagnosis and treatment.

贝赫切特病（Behcet’s disease, BD）是一种罕见的复发性自身炎症性疾病，以系统性血管炎为核心病理特征，典型临床表现为复发性阿弗他口炎（recurrent aphthous stomatitis, RAS）。本研究旨在筛选可区分贝赫切特病与特发性复发性阿弗他口炎的特异性血清蛋白。研究收集了12例贝赫切特病患者、12例特发性复发性阿弗他口炎患者及21名健康志愿者的外周血，血清样本采用基于串联质量标签的质谱分析进行检测。对鉴定获得的差异表达蛋白（differentially expressed proteins, DEPs）开展KEGG通路富集分析、基因本体（Gene Ontology, GO）分析及蛋白质相互作用（protein-protein interaction, PPI）分析。另设置验证队列（纳入18例贝赫切特病患者、18例特发性复发性阿弗他口炎患者及18名健康对照），采用酶联免疫吸附试验（Enzyme-Linked Immunosorbent Assay, ELISA）验证2种贝赫切特病特异性差异表达蛋白。与复发性阿弗他口炎患者血清相比，贝赫切特病患者血清中共鉴定出242个差异表达蛋白；与健康对照相比，贝赫切特病患者血清中有49个蛋白表达存在差异，而特发性复发性阿弗他口炎患者血清未出现该特征性变化。KEGG通路及基因本体分析结果显示，贝赫切特病与复发性阿弗他口炎患者的差异表达蛋白具有相似的生物学功能与细胞分布特征，且显著富集于凝血调控及免疫应答相关通路。对比贝赫切特病与复发性阿弗他口炎的差异表达蛋白，多种角蛋白（keratins）可作为区分二者的潜在标志物。本研究同时筛选出仅在贝赫切特病患者中存在差异表达的蛋白群。蛋白质相互作用分析显示，脂蛋白代谢调控因子为核心蛋白（hub proteins），提示其在贝赫切特病病理进程中可能发挥关键调控作用。此外，酶联免疫吸附试验结果证实，与健康供者相比，贝赫切特病患者血清中富亮氨酸α2糖蛋白1（Leucine-Rich Alpha-2-Glycoprotein 1, LRG1）与超氧化物歧化酶3（Superoxide Dismutase 3, SOD3）水平显著升高，而复发性阿弗他口炎患者无该血清学变化。本研究筛选得到可区分贝赫切特病与复发性阿弗他口炎的新型血清蛋白标志物，或可为贝赫切特病的临床诊断与靶向治疗提供潜在的科学依据与治疗靶点。