How does Rituximab affect the immune system?

Rituximab primarily targets CD20 antigen found on B-lymphocytes, leading to a decrease in B-cell count. This reduction is significant because B-cells are crucial players in the immune system, responsible for producing antibodies and contributing to the adaptive immune response. By binding to the CD20 antigen, Rituximab marks these B-cells for destruction by the body’s immune system, specifically through mechanisms such as complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity.

The primary therapeutic use of Rituximab is in conditions where excess B-cell production contributes to disease, such as certain types of lymphoma and autoimmune disorders like rheumatoid arthritis. By reducing the B-cell population, Rituximab effectively diminishes the pathological processes driven by these cells while having little to no direct impact on T-cell activity, macrophage enhancement, or antibody production in the immediate term.

This targeted action is why the choice indicating a decrease in B-cell count accurately reflects the role of Rituximab in influencing the immune system.