Abatacept as a Therapeutic Option for Rheumatoid Vasculitis.

Abatacept is a fusion protein composed of the fragment crystallizable region (Fc region) of the immunoglobulin IgG1 fused to the extracellular domain of cytotoxic T-lymphocyte-associated protein 4. Our patient presented with lower extremity purpura in the setting of rheumatoid arthritis and common variable immunodeficiency disease. A biopsy of cutaneous lesions confirmed the etiology of rheumatoid vasculitis. Although rituximab is the recommended treatment, it has the potential to exacerbate immunodeficiency. The cutaneous lesions responded well to abatacept after failure to respond to other treatment modalities. This case is the first, to our knowledge, to be reported in North America. Our case may encourage extensive clinical trials on abatacept as a treatment option.