Objectives. Advanced imaging modalities have shown that not only joints but also bones and tendon sheaths can be inflamed at diagnosis of RA. We aimed to better understand the time-order in which... Show moreObjectives. Advanced imaging modalities have shown that not only joints but also bones and tendon sheaths can be inflamed at diagnosis of RA. We aimed to better understand the time-order in which the inflamed tissues respond to DMARD treatment. Also, because ACPA status may reflect a different pathophysiology, differences in time-order of inflammation decrease were hypothesized between these disease types.Methods. A total of 216 consecutive patients presenting with RA (n = 1 7 6) or undifferentiated arthritis (n = 40) , who all started with conventional synthetic DMARD treatment, were studied. 1.5T contrast-enhanced hand and foot MRIs were performed before treatment and after 4, 12 and 24 months. Cross-lagged models evaluated the influence of two time patterns: a simultaneous pattern (`change in one inflammatory feature associated with change in another feature') and a subsequent pattern (`change in one inflammatory feature preceded change in another feature'). ACPA stratification was performed.Results. The median symptom duration at presentation was 13 weeks. Forty-four percent of patients was ACPA-positive. All pairs of inflammatory features decreased simultaneously in all time intervals (0-4/4-12/12-24 months; P< 0.05). Moreover, time-orders were identified: synovitis decrease preceded tenosynovitis decrease (0-4 to >4-12 months; P=0.02 and 4-12 to >12-24 months; P=0.03). Largely similar results were obtained in both ACPA subgroups. Additionally, in ACPA-positive but not ACPA-negative patients, synovitis decrease preceded osteitis decrease (4-12 to >12-24 moths; P= 0.002).Conclusion. This study increased the understanding of the response to treatment on the tissue level. In addition to simultaneous decrease of inflammation, synovitis decrease preceded tenosynovitis decrease. Differences in timeorder of inflammation decrease between ACPA subgroups suggest differences in underlying inflammatory pathways. Show less
Objectives. RF and ACPA are used as diagnostic tools and their presence has been associated with clinical response to some biologic DMARDs (bDMARDs) in RA. This study compared the impact of... Show moreObjectives. RF and ACPA are used as diagnostic tools and their presence has been associated with clinical response to some biologic DMARDs (bDMARDs) in RA. This study compared the impact of seropositivity on drug discontinuation and effectiveness of bDMARDs in patients with RA, using head-to-head comparisons in a real-world setting.Methods. We conducted a pooled analysis of 16 observational RA registries. Inclusion criteria were a diagnosis of RA, initiation of treatment with rituximab (RTX), abatacept (ABA), tocilizumab (TCZ) or TNF inhibitors (TNFis) and available information on RF and/or ACPA status. Drug discontinuation was analysed using Cox regression, including drug, seropositivity, their interaction, adjusting for concomitant and past treatments and patient and disease characteristics and accounting for country and calendar year of bDMARD initiation. Effectiveness was analysed using the Clinical Disease Activity Index evolution over time.Results. Among the 27 583 eligible patients, the association of seropositivity with drug discontinuation differed across bDMARDs (P for interaction <0.001). The adjusted hazard ratios for seropositive compared with seronegative patients were 1.01 (95% CI 0.95, 1.07) for TNFis, 0.89 (0.78, 1.02)] for TCZ, 0.80 (0.72, 0.88) for ABA and 0.70 (0.59, 0.84) for RTX. Adjusted differences in remission and low disease activity rates between seropositive and seronegative patients followed the same pattern, with no difference in TNFis, a small difference in TCZ, a larger difference in ABA and the largest difference in RTX (Lundex remission difference +5.9%, low disease activity difference +11.6%).Conclusion. Seropositivity was associated with increased effectiveness of non-TNFi bDMARDs, especially RTX and ABA, but not TNFis. Show less
