Final answer:
Agglutination is the process in which antibodies attach to antigens on red blood cells, causing the cells to clump together. This can lead to hemolysis and blockage of small blood vessels. The test for detecting this is often the Coombs' test, which can identify agglutination promoted by antibodies like IgG.
Step-by-step explanation:
The clumping of red blood cells (RBCs) due to the presence of an antibody directed against RBC surface antigens is known as agglutination. This occurs when the arms of Y-shaped antibodies bind randomly to antigens on the surfaces of RBCs, causing the cells to form clumps or masses. This process, called hemagglutination when it involves RBCs, can have significant consequences as the clumps can block small blood vessels, leading to tissue deprivation of oxygen and nutrients. Additionally, this can lead to hemolysis as the cells are degraded, releasing hemoglobin into the bloodstream which can then travel to the kidneys. The kidneys are responsible for filtration of the blood and handling the large amount of hemoglobin can be challenging for this organ. IgG is often the antibody bound to red blood cells in these conditions, and its presence can be detected with Coombs' reagent which promotes agglutination by linking IgG on neighboring cells.W