RESUMEN
The double and simultaneous molecular interaction between antigen-presentig cells (APC) and T lymphocytes is essential for the optimal activation of the immunological response and requires the participation of two membrane receptor groups. Abatacept is a fusion protein that selectively modulates one of these two ways, by binding to CD80 and CD86 receptors on APC. In this way, the drug inhibits T cell activation, selectively blocking the specific interaction of CD80/CD86 receptors to CD28 and, therefore, inhibiting T cell proliferation and B cell immunological response. This pharmacological action results in the normalization of inflammatory mediators in rheumatoid arthritis patients and in a safe and efficacious clinical response. Abatacept in combination with methotrexate prevents the progression of joint damage and improves physical function in rheumatoid arthritis patients.