[Intra-articular therapy with infliximab in psoriatic arthritis: efficacy and safety in refractory monoarthritis]

To evaluate efficacy and safety of intra-articular therapy (IA) with infliximab (IFX), in patients with psoriatic arthritis (PsA) and refractory monoarthritis.

Four male and 1 female aged from 25 to 71 years and disease duration from 1 to 25 years, affected by PsA (CASPAR criteria) were observed . All patients were treated with immunomodulators (methotrexate, leflunomide, cyclosporin A), 3/5 with concomitant steroids, 4/5 with NSAID's. Only 1 patient were treated with IFX 5 mg/kg IV every 6 weeks. Before the IFX injection an amount of synovial fluid was aspired from the inflamed site and the anti-TNF injection was echographic guided. Patients were evaluated at regular intervals through clinical and echographic examination and retreated in case of flare.

At follow-up visit after 7 days, in all patients treated with the first injection was detected total regression of the inflammation and no new inflamed synovial fluid was observed; power doppler examination shows reduction of local vascularization. Two patients experienced full remission after 6 months and only one injection, 1 patient (arthritis of the wrist) was in remission after 2 injections (3 months of interval). In 2 patients with knee arthritis and important synovial hypertrophy good results obtained after the first injection were not maintained afterwards and second injection was ineffective: these patients were evaluated for surgical intervention.

Local injections of IFX were safe and well tolerated in all patients. The efficacy in short term was observed in all cases; our supposition is that presence of synovial hypertrophy is cause of worsening.