Abatacept is used in treatment of which of the following conditions?

Ans. A. Rheumatoid ArthritisAbatacept is a fusion protein composed of Fc region of IgG1 fused to extracellular domain of CTLA-4. It inhibits the co-stimulation of T cells by blocking CD28-CD80/86 interactions. In order for a T cell to be activated, an APC must present two signals to the T cell. One of those signals is the MHC combined with the antigen, and the other signal is the CD80/CD86 molecule. Abatacept binds to CD80 and CD86 molecule and prevents second signal.Belatacept is FDA approved for kidney transplant recipients and is given monthly as an intravenous infusion.