A7.6 Clinical and pathological differences of elderly- and younger-onset rheumatoid arthritis in an early arthritis cohort. (13th February 2015) - Romão, VC
Abstract : Background and objectives: Elderly-onset rheumatoid arthritis (EORA), starting after the age of 60, is a subset of disease with different characteristics from the classic younger-onset RA (YORA). We aimed to compare clinical and pathological features between these two disease subsets in the Barts Early Arthritis Cohort (BEAC). Material and methods: We included BEAC patients fulfilling ACR 2010 criteria and assessed clinical and pathological variables at baseline and at 6 months of DMARD therapy. The primary outcome was the achievement of low disease activity (LDA) according to DAS28 at 6 months. We used multivariate logistic regression to determine predictors of LDA at 6 months. Results: We included 140 patients, 99 YORA and 41 EORA. EORA patients were more frequently male (51.2 vs. 26.3, p = 0.004) and Caucasian (68.3 vs. 39.4, p = 0.02), had more proximal joint involvement at presentation (55.0 vs. 35.1, p = 0.031), more common abrupt (27.5 vs. 4.1, p < 0.001) and polymyalgia rheumatica (PMR)-like onset (23.7 vs. 0, p < 0.001), weight loss (15.0 vs. 4.1, p = 0.026), anaemia (48.6 vs. 28.4, p = 0.033), extra-articular manifestations (27.5 vs. 6.2, p = 0.004) and cardiovascular comorbidity (73.2 vs. 29.3, p < 0.001). At baseline, disease activity parameters, including ESR, CRP, joint counts, and composite scores (DAS28, CDAI and SDAI), were similar between both groups. Synovial pathotype classification (ectopic lymphoid-like structures positive (ELS+); diffuse myeloid infiltrate or non-inflammatory/pauci-immune) did not reveal differences between groups as a whole (p = 0.12). However, EORA patients presented pauci-immune pathotype less frequently (25.0 vs. 44.3, p = 0.045). Macrophage, B-cell, T-cell and plasmocyte semi-quantitative scores were also similar. At 6 months (n = 105), EORA (OR = 0.28, p = 0.047), female gender (OR = 0.23, p = 0.016), current smoking (OR = 0.11, p = 0.002) and high baseline DAS28 (OR = 0.41, p < 0.001) were negatively associated with reaching DAS28 LDA. Contrastingly, PMR-like onset was strongly predictive of DAS28 LDA (OR = 63.9, p = 0.004). Conclusions: In an early arthritis cohort, EORA patients presented different clinical features at presentation, but similar synovial pathological characteristics. Adjusting for other significant factors such as gender, smoking, baseline DAS28 and PMR-like onset, EORA was negatively associated with the achievement of LDA at 6 months according to DAS28.