Background The 1987 ACR classification criteria (OLD/RA) had the disadvantage of including features related to damage or prolonged disease, such as erosions/ rheumatoid nodules. The new ACR/EULAR criteria (NEW/RA) allows classification of patients with early disease prior to damage. This is important as earlier diagnosis and treatment has been shown to improve outcome.
Objectives We aimed to compare the US findings of patients fulfilling each criterion to examine the impact of NEW/RA on disease characteristic particularly disease duration.
Methods A total number of 2730 hand, wrist, elbow, shoulder, knee, ankle and feet joints of 105 consecutive patients registered in early arthritis register either fulfilling RA criteria (60 patients fulfilling the OLD/RA, 22 patients with the NEW/RA/not fulfilling the OLD/RA) or with undifferentiated arthritis (23 patients) were scanned by US. The sonographer was blinded to the diagnosis and clinical assessments. Synovitis, erosions and power Doppler (PD) findings were scored on a scale between 0-3; being 0: none, 1: mild, 2: moderate and 3 for severe US findings and those were added up to calculate a synovitis, PD and erosion scores for each patient.
Results Patients with OLD/RA had similar SJC, TJC, CRP, acute phase response, patient global and DAS28 scores with NEW/RA patients (table1). Disease duration was longer in OLD/RA (39±38 months) compared to NEW/RA (17±13; p= 0.008) but statistically not different from patients with undifferentiated arthritis (25±17 months). Both OLD/RA and NEW/RA groups had similar synovitis scores and PD scores whereas erosion scores were higher in patients with OLD/RA (p=0.009).
Patients with undifferentiated arthritis were older than RA patients. These patients had fewer swollen joints than NEW/RA patients (p=0.017). All the other disease activity parameters were similar compared with both NEW/RA and OLD/RA. Both the synovitis scores (p=0.006) and erosion scores (p=0.007) of patients with undifferentiated arthritis were lower than OLD/RA despite being similar to NEW/RA.
Conclusions The new ACR/EULAR RA criteria allowed classification of patients with less damage but similar disease activity (as detected by clinical assessment and synovitis & PD by US). The similar disease activity should ensure suitability for intervention whilst shorter duration and less damage should improve outcome with patient benefit.
Disclosure of Interest None Declared