Anakinra is used in rheumatoid arthritis and works by which mechanism?

• A. T-cell co-stimulation modulator
• B. Interleukin-1 receptor antagonist
• C. Anti-CD20 B-cell depleter
• D. Antibody against TNF-α

Answer: (B)

In rheumatoid arthritis, the inflammatory signal from interleukin-1 (IL-1) drives joint inflammation and damage. Anakinra acts as a competitive antagonist at the IL-1 receptor, meaning it binds the receptor without activating it. This blocks IL-1 from signaling, dampening the inflammatory cascade and reducing joint inflammation. It’s a recombinant form of the natural IL-1 receptor antagonist, so its effect is specifically to shut down IL-1–mediated pathways rather than affecting T-cell co-stimulation, depleting B cells, or neutralizing TNF-α.