Tumour necrosis factor α blockers are more effective than methotrexate in the inhibition of radiographic joint damage progression among patients with psoriatic arthritis

Aim To determine whether tumour necrosis factor alpha (TNF alpha) blockers are more effective than methotrexate in inhibiting the progression of radiographic joint damage in patients with psoriatic arthritis (PsA). Methods A cohort analysis of patients followed prospectively in a large PsA clinic was conducted. Patients who received a TNF alpha blocker were compared to those treated with methotrexate. Patients who had records of at least 12 months of treatment with either medication for active peripheral PsA and had radiographic bone erosions were analysed. Radiographs of the hands and feet were performed at baseline, 1-2 years (time 1) and 3-4 years (time 2). Radiographic joint damage was scored according to the modified Steinbrocker score. The outcome of interest was the occurrence of radiographic progression. Multivariate logistic regression analysis using generalised estimating equations for repeated measures was used to compare progression in radiographic joint damage between the two treatment groups. Results 65 patients treated with TNF alpha blockers and 70 patients treated with methotrexate were analysed. The proportion of patients who demonstrated progression of radiographic damage score at time 1 and time 2 was higher in the methotrexate group compared to the TNF alpha blockers group (at time 1: 80% vs 58.9% p=0.005; at time 2: 88% vs 61% p=0.005). In the multivariate regression analysis methotrexate treatment was associated with an increase in radiographic damage compared to TNF alpha blockers (p=0.001). Conclusions In a clinic setting, patients with erosive PsA receiving TNF alpha blockers had a better radiographic outcome compared to those treated with methotrexate.