Treating psoriatic arthritis: how effective are TNF antagonists?

Psoriatic arthritis (PsA) is a seronegative spondyloarthropathy that commonly appears after the onset of the characteristic cutaneous lesions. This complication affects about 40% of patients with moderate to severe cutaneous disease. Analysis of synovial fluid and tissue in patients with PsA demonstrates a profile of high levels of tumor necrosis factor (TNF) plus other cytokines similar to those seen in patients with rheumatoid arthritis (RA). In the past, medical management of patients with this disease consisted of treatment with nonsteroidal anti-inflammatory agents. Patients with more severe disease have tried a number of different disease-modifying drugs including methotrexate, azathioprine, and gold salts. However, there is no evidence that these agents can arrest the progress of structural joint damage. Infliximab and etanercept are TNF antagonists that have demonstrated significant efficacy and safety in patients with RA. Clinical trials with these two agents in patients with PsA have shown significant improvement in the rheumatologic and cutaneous manifestations of the disease.