Which of the following is the primary function of C-reactive proteins?

The primary function of C-reactive proteins (CRP) is to induce inflammation, making the first choice the correct answer. CRP is an acute-phase protein produced by the liver in response to inflammatory stimuli, particularly those from infection or tissue injury. Its levels rise dramatically in the presence of inflammation, serving as a key marker in clinical settings to indicate acute inflammatory processes.

Through the induction of inflammation, CRP helps to activate the complement system and assists in marking pathogens and damaged cells for clearance. While it also plays roles in binding to pathogens and enhancing opsonization—that is, promoting phagocytosis—its overarching primary action is to signal inflammation and initiate the immune response.

The other options, such as binding to pathogens for phagocytosis and facilitating antibody production, describe functions associated with different immune components. CRP itself does not directly facilitate antibody production; this is primarily the role of B cells and specific cytokines within the immune response. Neutralizing toxins is typically the function of antibodies or other molecules specifically designed for that purpose. Thus, while CRP has supportive roles in these processes, its main function is tied to the inflammatory response, which is critical in the body’s defense and healing mechanisms.