Abatacept in the treatment of psoriatic arthritis: biological and clinical profiles (of the responders).

Abatacept (CTLA4Ig), a selective T-cell costimulation modulator, has been approved for the treatment of psoriatic arthritis patients with an inadequate response to conventional synthetic disease-modifying antirheumatic drugs, but not for those with uncontrolled skin lesions, nor with axial involvement. In this review, we will try to interpret such a differential efficacy of abatacept on the psoriatic arthritis clinical domains, on the basis of its differential effectiveness on the diverse T-cell subsets at different sites. Clinical and biological profiles of abatacept possible responders will be provided.