Agglutination is an antibody-mediated immune process in which pathogens are clumped together, enabling neutralization and opsonization. This statement is:

• A. True
• B. False
• C. Partially true
• D. Not documented

Answer: (A)

Agglutination is the antibody-mediated clumping of antigens on microbes or particles, which physically links them into larger complexes. This clumping interferes with the pathogen’s ability to infect by preventing attachment to host cells (neutralization) and creates larger targets for phagocytes, making it easier for immune cells to recognize and engulf them (opsonization). IgM is particularly effective at this because its pentameric structure provides many binding sites to cross-link multiple antigens at once, though IgG can also mediate agglutination. Because the clumping directly contributes to reducing infectivity and enhancing clearance by phagocytosis, the statement is true. While other immune mechanisms also assist in neutralization and clearance, agglutination itself clearly facilitates both processes.