Ab0149 characterisation of Rheumatoid Arthritis Progression in an Early Undifferentiated Arthritis Cohort

Abstract

Background:Since the publication of 2010 ACR/ELUAR classification criteria for Rheumatoid Arthritis (RA), identification of patients with RA at early stages of the disease has improved. Nevertheless, up to 56% of patients are diagnosed with undifferentiated arthritis (UA) at the first visit to Rheumatology Departments, of which about 20-30% will progress to RA. For this reason, Early Arthritis Clinics (EAC) have been progressively implemented in Rheumatology departments in order to identify and have a tight follow-up of these patients.Objectives:a) To analyze the progression rate from UA to RA in a cohort of EAC. b) To identify differences in clinical features at baseline that characterize the progression to RA of these patients.Methods:Prospective study from a cohort of EAC between 2010 and 2018. Patients diagnosed with UA at first consultation were included and with a follow-up of 2-years. Final diagnosis was assessed at the end of study period defining two groups: RA progression (RA-group) vs no progression (non-RA-group).Baseline characteristics were recorded for both groups: sex, age, smoking habit, duration of symptoms, morning stiffness, tender joint count (TJC), swollen joint count (SJC), Rheumatoid Factor (RF), Anti-Citrullinated-Peptide-Antibodies (ACPA), DAS-28, erythrocyte sedimentation rate (ESR), C-Reactive Protein (CRP), Pain visual analogue scale (VAS). Differences in sociodemographic, clinical and serological features between groups were analyzed using T-test, chi-square test and U-Mann Whitney depending on the nature of variables.Results:A total of 228 patients with UA were included, of which 54 (23,3%) progressed to RA (patients characteristics are shown in table 1). Regarding serological characterization, we found that in our cohort, 44.4% of patients who developed RA had FR and ACPA positivity, 13% RF positive, 7.4% ACPA positive. In contrast 35% patients were seronegative. From non-RA group, 73% of patients were seronegative, 18% RF positive, 4.5% ACPA positive and 4.5% double positive.Table 1.VariableTotal (n=228)RA (n=54)Non-RA (n=174)p-valueFemale sex n(%)165 (71.7)42 (77.8)121 (69.5)0.31*Age (mean SD)51.47 (16.46)52.9 (16.15)51.26 (16.61)0.53§Smoking habit n (%)0.12*-smokers49 (21.2)14 (25.9)33 (19)-exsmokers52 (22.5)15 (27.8)37 (21.3)-non-smokers113 (48.9)19 (35.2)93 (53.4)Duration of symptoms (weeks) (median IQR)8 (4-19)12 (8-24)8 (4-16)0.006¶Morning stiffnes >60min n (%)53 (22.9)15 (27.8)38 (21.8)0.26*Patient health assessment (meadian IQR)39 (16-68)58 (22-75)34 (14-64)0.01¶Pain (VAS) (median IQR)45 (18-68.2)54 (30-71)39 (14.5-67.5)0.02¶Tender Joint Count (median IQR)2 (1-6)4 (1-9)2 (1-6)0.04¶Swollen Joint Count (median IQR)2 (1-4)3 (1-6)2 (1-4)0.01¶Baseline DAS28 (mean SD)3.97 (1.39)4.44 (1.54)3.82 (1.33)0.006§HAQ (median IQR)0.75 (0.25-1.5)1.12 (0.37-1.56)0.62 (0.12-1.37)0.06¶CRP(mean SD)2.2 (8.01)1.39 (3.25)2.3 (8.9)0.44§ESR (mean SD)23.74 (19.5)24.62 (16.22)22.8 (19.3)0.54§RF n (%)70 (30.3)31 (57.4)39 (22.4)<0.001*ACPA n (%)44 (19)28 (51.9)16 (9.2)<0.001*No differences between age at onset, sex an smoking habit were found. Duration of symptoms until first visit to Rheumatology Department was longer RA-group. Regarding joint involvement, TCJ and SCJ were higher in RA-group at baseline and also VAS pain and patients´global health assessment.Conclusion:One out of four patients diagnosed with early UA are at risk of RA development within the following 2 years. This fact implies that these patients benefit from EAC in order to have a tight control of the disease and have the chance of starting treatment as soon as possible.References:Combe B et al. 2016 update of the EULAR recommendations for the management of early arthritis. Ann Rheum Dis 2017;76:948-959.van Steenbergen HW et al. Preventing progression from arthralgia to arthritis: targeting the right patients. Nat Rev Rheumatol. 2018 Jan;14(1):32-41.Disclosure of Interests:None declared