Which term is used to denote the clumping of red blood cells that can be life-threatening?

Agglutination is the term specifically used to describe the clumping of red blood cells that can have serious consequences, potentially even being life-threatening. This process occurs when antibodies in the blood bind to specific antigens on the surface of red blood cells, leading to their clumping. This can happen in various situations, such as during a transfusion reaction when incompatible blood types are mixed, resulting in the immune system attacking the transfused cells. Agglutination can obstruct blood flow, damage blood vessels, and result in organ damage if not addressed promptly.

In contrast, rouleaux refers to a formation of red blood cells that stack together like coins; while this phenomenon can indicate certain conditions, it does not typically pose an immediate life threat. Aggregates can refer to clusters of cells but are not specific to red blood cells or inherently dangerous. Clotting involves the process of blood coagulation to stop bleeding, which is a normal body function rather than a pathological condition associated with the dangerous clumping of red blood cells. Therefore, agglutination is the most accurate term to identify this specific and potentially critical situation.