Risk profiling for a refractory course of rheumatoid arthritis.

BACKGROUND: Despite modern therapeutics and treatment strategies, a subset of rheumatoid arthritis (RA) patients remains insufficiently responsive to multiple therapies. Here, we identify predictors of such refractory RA ("reRA"). METHODS: Patients from a longitudinal academic clinical database with reRA (defined as failing to reach the treatment target of at least low disease activity with ≥3 DMARD courses, including ≥1 biological, over a total of ≥18 months) were compared to patients who did respond within the first two treatments (treatment amenable RA, "taRA"). We performed logistic regression analysis to identify risk factors for refractory disease, and several sensitivity analyses concerning different potential definitions for reRA to confirm the robustness of the results; key findings were also validated in an independent community cohort. RESULTS: We enrolled 412 patients, of whom 70 were reRA and 102 taRA; 240 patients fulfilled neither definition. ReRA patients were more frequently female (92.9 vs. 70.6%, p < 0.001), younger (44.37 vs. 51.14 years, p = 0.002), and had higher CDAI levels at first presentation (26.06 vs. 15.39, p < 0.001). Treatment delay was significantly longer for reRA than for taRA (3.17 vs. 1.45 years, p = 0.001). In multivariable analyses, treatment delay, female gender and higher disease activity remained as independent predictors of refractory disease. Based on the identified predictors, we developed a matrix model for risk of future reRA. CONCLUSIONS: Our data identified delay to initial treatment, female gender and higher disease activity as important predictors of a later refractory course of RA. Delay of treatment initiation is the single most important modifiable risk factor of refractory disease.

Early response to therapy predicts 6-month and 1-year disease activity outcomes in psoriatic arthritis patients.

Objectives: In PsA management, remission and low disease activity represent preferential treatment targets. We aimed at evaluating the predictive value and clinical use of initial therapeutic response for subsequent achievement of these targets. Methods: Based on data of 216 patients enrolled in a randomized controlled trial of golimumab (GO-REVEAL), we performed diagnostic testing analyses using 3- and 6-month disease activity as tests for treatment outcomes to understand the implications of early response. In regression analyses, we estimated the probabilities for achieving at least LDA. Disease activity was measured by the disease activity index for PsA (DAPSA). Results: Three-month DAPSA levels were excellent tests for disease activity at 6 months (and at 1 year), with areas under the receiver operating characteristic curves of 0.92 (and 0.88, respectively). The estimated probability for 6-month LDA could be quantified as <22% if patients did not reach at least moderate disease activity after 3 months on golimumab. Similar data were seen for early DAPSA response: patients achieving a DAPSA 85% at 3 months had an 84% probability for 6-month LDA or REM. All results were validated in an independent trial cohort of patients treated with infliximab (IMPACT 2). Conclusion: Three months after implementation of therapy in PsA, it is already possible to evaluate the potential for accomplishing therapeutic goals. This substantiates the choice of the 3-month assessment as essential for treatment adaptations.