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What is Abatacept is a new drug approved for: and explain in detail?
Ans. (B) Rheumatoid arthritis(Ref: Harrison 18th/2748)Abatacept is a co-stimulation inhibitor. Two signals are required for activation of T-cells:1. Main signal: Interaction of T-cell receptor (TCR) with MHC of antigen presenting cells (APC)2. Co-stimulatory signal: Interaction of CD 28 of T-cells with CD-80/86 of APC.When both signals are present, T-cell gets activated. Abatacept acts by blocking the co-stimulatory signal and prevents activation of T-cells. It is approved for treatment of Rheumatoid arthritis.