肢端MRI能否在未分化关节患者中甄别出RA患者

Nieuwenhuis WP, et al. EULAR 2015.Present ID: OP0164.

背景：大量研究证实，RA治疗越早,患者转归越好，提示需尽早识别潜在的早期RA患者。磁共振成像（MRI）已被证明检测关节侵蚀和炎症敏感。已证实MRI可辅助鉴别未分化关节炎（UA）患者中的RA患者，但MRI在RA诊断的价值仍不清楚。

目的：在2010 RA分类标准中增加肢端MRI (MCP和腕),测试这一改良标准是否能从未分化关节炎患者中准确甄别RA。

方法：纳入2010年8月至2013年8月荷兰莱顿早期关节炎门诊的205例关节炎患者,这些患者均不符合RA分类标准以及其它关节炎诊断标准。单边1.5T磁共振扫描MCP和腕关节。由有经验的阅片者根据RA-MRI评分系统（RAMRIS）进行打分，结果评价为符合1987 RA标准或第一年应用DMARDs。同时2010年标准与标准结合MRI表现进行比较。MRI评分阳性（RAMRIS≥1）敏感性分析cut-off≥2。

结果：患者平均年龄55岁，61％为女性，关节肿胀的中位数为3，平均症状持续时间为10.7周，22％ACPA阳性。第一年，47例（23％）患者符合1987年RA诊断标准，96例（47％）患者服用DMARDs。符合2010诊断标准及应用DMARDs的灵敏性为40％（95％CI为33％至46％），特异性为88％（95％CI为84％至93％），准确性为65％（95％CI 59％至72％）和AUC为0.64（95％CI 0.56至0.72）。符合2010年诊断标准及MRI存在滑膜炎时，灵敏性提高到91％（95％CI为87％至95％））和特异性降低到28％（95％CI为21％至34％），准确性57％（95％CI为50％至64％）和AUC为0.59（95％CI 0.54至0.64），AUC两者间没有显著差异。符合2010标准及骨髓水肿、符合2010标准及MRI示骨侵蚀及1987标准的敏感性和特异性等与上述结果无明显的差异。如果将MRI评分阳性定义为RAMRIS≥2，亦无明显的差异。

结论：相比2010标准,添加MRI结果,可增加RA检测的敏感性,但相对的特异性和准确性降低,且AUC没有改善。如何从UA患者中准确甄别RA患者，需对MRI表现哪些具有特异性进行更彻底的评估。故据目前的数据,还需考虑炎症的严重性和位置。故将MRI检测滑膜炎, BME或侵蚀的信息加入2010诊断标准,不提高UA患者确诊RA的进程。

原文链接或参见以下信息。

Ann Rheum Dis 2015;74:131 doi:10.1136/annrheumdis-2015-eular.2342

Oral Presentations

OP0164 Can Information Obtained by Extremity MRI at Disease Presentation be Used to Identify Rheumatoid Arthritis Among Undifferentiated Arthritis Patients?

¹Rheumatology

²Radiology, Leiden University Medical Center, Leiden, Netherlands

Abstract

Background There is compelling evidence that early treatment of rheumatoid arthritis (RA) associates with better disease outcome, underlying the need of early identification of RA. Magnetic resonance imaging (MRI) has been proven sensitive in detecting joint erosion and inflammation. Although it has been suggested that extremity MRI can aid in differentiating RA patients from undifferentiated arthritis (UA) patients, the value of MRI in diagnosing RA is still unclear.

Objectives To evaluate if the addition of extremity MRI findings to the 2010 RA classification criteria is beneficial to accurately diagnose RA in UA patients.

Methods 205 early arthritis patients, included in the Leiden early arthritis clinic between August 2010 and August 2013, that did not fulfill the 1987 RA criteria or did not have other rheumatic diagnoses were studied. Patients underwent unilateral 1.5T MRI of the MCP and wrist joints at inclusion. MRIs were made and scored following the RA-MRI-scoring system (RAMRIS) by one experienced reader (intra-observer intraclass correlation 0.925). The outcome measures were fulfilling the 1987 RA criteria or the start of disease modifying anti rheumatic drugs (DMARDS) within the first year. The diagnostic accuracy of the 2010 criteria alone and the criteria combined with MRI findings (presence of erosions, bone marrow edema and synovitis) were compared. An MRI-feature was scored positive if the score of that RAMRIS-feature was ≥1; sensitivity analyses were also run on a cut-off of ≥2.

Results Patients had a mean age of 55, 61% were women, the median number of swollen joints was 3, median symptom duration was 10.7 weeks and 22% was ACPA-positive. During the first year, 47 patients (23%) fulfilled the 1987 RA criteria and 96 patients (47%) were prescribed DMARDs. When studying the start of DMARDS as outcome and applying the 2010 criteria the sensitivity was 40% (95%CI 33% to 46%), specificity 88% (95%CI 84% to 93%), accuracy 65% (95%CI 59% to 72%) and the AUC 0.64 (95%CI 0.56 to 0.72). When the presence of synovitis on MRI was combined with the 2010 criteria, the sensitivity increased to 91% (95%CI 87% to 95%)) and the specificity decreased to 28% (95% CI 21% to 34%)); the accuracy (57% (95%CI 50% to 64%)) and AUC (0.59 (95%CI 0.54 to 0.64)) did not differ significantly. Similar data were found for the addition of bone marrow edema or MRI detected erosions to the 2010-critieria. Similar findings were obtained when evaluating fulfillment of the 1987 criteria after 1-year as outcome. When a MRI was defined positive for a finding with a score ≥2, data were also comparable.

Conclusions Adding MRI findings to the 2010 criteria for RA increased the sensitivity compared to the criteria alone, but at the cost of a considerable decrease in specificity and the accuracy and AUC did not improve. More thorough evaluations are needed to determine which MRI findings are specific for RA in UA patients. It also needs to be determined if the severity and location of inflammation needs to be taken into account. Based on the present data we conclude that adding information on the presence of any MRI-detected synovitis, BME or erosions to the 2010 criteria does not improve the diagnostic process of RA in UA patients.