Hand and foot MRI in contemporary undifferentiated arthritis: in which patients is MRI valuable to detect rheumatoid arthritis early? – a large prospective study

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Rheumatology (Oxford). 2022 Jan 12:keac017. doi: 10.1093/rheumatology/keac017. Online ahead of print.

ABSTRACT

OBJECTIVES: Identifying patients that will develop rheumatoid arthritis(RA) among those presenting with undifferentiated-arthritis(UA) remains a clinical dilemma. Although magnetic-resonance-imaging(MRI) is helpful according to EULAR-recommendations, this has only been determined in UA-patients not fulfilling 1987-RA-criteria, whilst some of these patients are currently considered as RA because they fulfill the 2010-criteria. Therefore, we studied the predictive value of MRI for progression to RA in the current UA-population: i.e. not fulfilling RA-classification-criteria (neither 1987- or 2010-criteria) and not having an alternate diagnosis. Additionally, the value of MRI was studied in patients with a clinical diagnosis of UA, regardless of the classification-criteria.

METHODS: Two UA-populations were studied: criteria-based-UA as described above(n = 405) and expert-opinion-based-UA(n = 564), i.e. UA indicated by treating rheumatologists. These patients were retrieved from a large cohort of consecutively included early arthritis patients that underwent contrast-enhanced MRI-scans of hand-and-foot at baseline. MRIs were scored for osteitis, synovitis and tenosynovitis. Patients were followed for RA-development during 1-year. Test-characteristics of MRI were determined separately for subgroups based on joint-involvement and autoantibody-status.

RESULTS: Among criteria-based-UA-patients(n = 405), 21% developed RA. MRI-detected synovitis and MRI-detected tenosynovitis were predictive. MRI-detected tenosynovitis was independently associated with RA-progression(OR 2.79; 95%CI 1.40-5.58), especially within ACPA-negative UA-patients(OR 2.91; 1.42-5.96). Prior risks of RA-development for UA-patients with mono-/oligo-/polyarthritis were 3%, 19%, 46%, respectively. MRI-results changed this risk most within the oligoarthritis-subgroup: PPV was 27% and NPV 93%. Similar results were found in expert-opinion-based-UA(n = 564).

CONCLUSION: This large cohort-study showed that MRI is most valuable in ACPA-negative UA-patients with oligoarthritis; a negative MRI could aid in preventing overtreatment.

PMID:35022703 | DOI:10.1093/rheumatology/keac017