A predictive model for remission and low disease activity in patients with established rheumatoid arthritis receiving TNF blockers.

The objective of this study was to identify predictors for remission or low disease activity (LDA) in established rheumatoid arthritis (RA) at 12 months of anti-TNF-α therapy. We have performed a prospective observational study in 90 consecutive patients with active RA receiving TNF-α inhibitors. Baseline and standard assessments were done every 3 months, including individual parameters (clinical and biological) and composite activity scores (28-joint disease activity score, DAS28). The primary outcome measure was DAS28-based EULAR response criteria. The multivariate logistic regression was used to analyze the association between disease activity and several RA baseline characteristics. Of the RA, 78.8 % was classified as good responders based on the EULAR-DAS28 criteria, 44.4 % RA achieving remission (DAS28 ≤ 2.6) and 34.4 %, LDA (DAS28 ≤ 3.2). Parameters associated with an increased likelihood of remission and LDA were initial DAS28-erythrocyte sedimentation rate ≤ 7 (odds ratio (OR) 3.3, 95 % confidence interval (CI) 2.03-5.81; OR 1.8, 95 % CI 1.09-6.68), Health Assessment Questionnaire Disability Index ≤  2 (OR 7.0, 95 % CI 1.56-31.91; OR 1.3, 95 % CI 1.03-5.79), C-reactive protein level ≤ 20 mg/l (OR 1.5, 95 % CI 0.29-8.22; OR 0.5, 95 % CI0.08-2.97), rheumatoid factor ≤ 20 IU/ml (OR 18.9, 95 % CI 10.79-38.36; OR 32.9, 95 % CI 4.03-269), anti-cyclic citrullinated peptide antibodies ≤ 40 IU/ml (OR 3.5, 95 % CI 0.67-18.19; OR 1.2, 95 % CI 1.02-1.59), concurrent prednisolone (OR 0.2, 95 % CI 0.05-0.36; OR 0.2, 95 % CI 0.06-0.63), methotrexate or leflunomide (OR 1.6, 95 % CI 1.2-13.53; OR 2.9, 95 % CI 1.20-4.36). A predictive matrix for remission and LDA in established active RA patients receiving TNF-α inhibitors was proposed. Further studies are necessary to confirm the value of such matrix in particular RA settings, leading to optimization of the use of anti-TNF-α therapy.