ARD：骨侵蚀关节数目可对ACR/EULAR 2010RA诊断标准中的特征性骨侵蚀进行定义

依据2010年的ACR/EULAR 类风湿关节炎分类标准，符合6条以上标准或存在典型骨侵蚀可诊断为类风湿关节炎（RA）。然而，RA特征性的骨侵蚀还没有明确定义。针对这一情况，来自于荷兰莱顿大学医学中心风湿免疫科的Rachel Knevel等人进行了一项研究，该研究主要是报道欧洲抗风湿病联盟（EULAR）的一些数据结果，目的是对RA特征性的骨侵蚀进行定义。研究结果在线发布在2013年4月的《风湿病学年鉴》(Ann Rheum Dis)上。研究表明，RA特征性的骨侵蚀能通过发生骨侵蚀关节数目的多少进行定义，这一判定方法具有高度的特异性，并在多种不同结局的两个独立的队列中得到证实。而影像学标准将在下一阶段的研究中进一步确立。

研究对象包括980位荷兰籍和811位法国籍的早期关节炎患者。研究者分析了受试者基线时手和足关节的影像学资料，研究发生骨侵蚀关节的部位及数量。研究的结局定义为疾病的第一年和关节症状出现5年之后，需甲氨蝶呤（MTX）或任何改变病情的抗风湿药物（DMARD）治疗。研究者并对满足2010年美国风湿病协会/EULAR 标准条数<6条的患者进行二次分析。

研究结果发现，两个队列在三种结局，包括MTX治疗、任何DMARDs治疗和持续关节炎的发生方面均具有可比性。骨侵蚀累及关节数目这一检测特征不受骨侵蚀部位影响。1个关节发生骨侵蚀时的检测特异性>50%；≥3个关节发生骨侵蚀时，特异性>80%；≥5个关节发生骨侵蚀时，特异性>90%。对不满足2010年标准的患者（n=308 和 149）进行分析时发现，1个关节发生骨侵蚀时，特异性>60%；≥3个关节发生骨侵蚀时，特异性>90%，≥5个关节发生骨侵蚀时，特异性>95%。极少数的患者满足影像学标准：三种结局各有27-36位患者出现大于等于3个关节的骨侵蚀，各有13-14位患者发生大于等于5个关节的骨侵蚀。

研究发现，RA特征性的骨侵蚀能通过发生骨侵蚀关节数目的多少进行定义，这一方法具有高度的特异性，并在多种不同结局的两个独立的队列中得到证实。下一阶段的研究将进一步确定影像学标准。

Defining erosive disease typical of RA in the light of the ACR/EULAR 2010 criteria for rheumatoid arthritis; results of the data driven phase.
BACKGROUND
According to the 2010 criteria, rheumatoid arthritis (RA) can be classified in the presence of ≥6 points on the criteria or 'typical' erosive disease. RA-specific erosiveness however has not been defined yet. This study reports the results of the data driven phase of a European League Against Rheumatism (EULAR) taskforce aiming to define RA-specific erosiveness.
METHODS
Baseline radiographs of hands and feet of 980 Dutch and 811 French early arthritis patients were studied on the number and site of erosive joints. Test characteristics were determined, with the outcome measures being initiation of methotrexate (MTX) therapy or any disease modifying antirheumatic drug (DMARD) therapy within the first year of disease and arthritis persistency over 5 years. Analyses were repeated in the patients with <6 points on the American College of Rheumatology/EULAR 2010 criteria.
RESULTS
In both cohorts comparable test characteristics were observed for the outcomes MTX therapy, any DMARD therapy and arthritis persistency. Test characteristics were not influenced by the site of erosiveness. The specificity observed was >50% for ≥1 erosive joint, >80% for ≥3 erosive joints and >90% for ≥5 erosive joints. When analysing the patients not fulfilling the 2010 criteria (n=308 and 149), specificity was >60% for ≥1 erosive joint, >90% for ≥3 erosive joints and >95% for ≥5 erosive joints. Few of these patients fulfilled the radiological criterion; 27-36 patients had ≥3 erosive joints and 13-14 patients had ≥5 erosive joints.
CONCLUSIONS
RA-specific erosiveness can be defined with high specificity at several cut-offs for the number of erosive joints in two independent cohorts with multiple different outcomes. The final radiological criterion will be established in the next phase.