Infusion reactions associated with rituximab are primarily related to which immune response component?

• A. Complement activation
• B. B-cell activation
• C. T-cell activation
• D. Antibody-antigen interaction

Answer: (D)

Infusion reactions associated with rituximab are primarily linked to antibody-antigen interactions. Rituximab is a monoclonal antibody that targets the CD20 antigen on B-cells, leading to their destruction. When rituximab is administered, it binds to its target, triggering a cascade of immune responses due to the interaction between the antibody and the CD20 antigen present on the surface of B-cells. This binding can lead to the release of pro-inflammatory cytokines and result in symptoms such as fever, chills, and hypotension during the infusion.

The infusion reaction, therefore, is a direct consequence of this antibody-antigen interaction, as the body recognizes the foreign antibody and mounts an immune response against both the rituximab and the activated B-cells.

While complement activation, B-cell activation, and T-cell activation all play roles in the overall immune response, the immediate infusion reactions specifically arise from the interaction between the administered rituximab and the CD20 antigen, making the antibody-antigen interaction the primary component involved in these reactions.