Which form of crossmatch interference involves an immune response against red blood cells?

The correct choice, cold agglutination, is a form of crossmatch interference that occurs when IgM antibodies bind to red blood cells at lower temperatures, typically around the temperatures found in the peripheral circulation (i.e., below body temperature). When blood samples are stored or processed at this cooler temperature, these antibodies can agglutinate the red blood cells, leading to false-positive results in compatibility testing or crossmatching. This can result in the appearance of a greater number of agglutinated cells than would be present at the standard incubation temperature.

Cold agglutinins are often seen in certain conditions, such as infections from viruses or certain autoimmune conditions. Understanding this phenomenon is crucial because if a crossmatch is interpreted incorrectly due to cold agglutination, it could lead to the inappropriate transfusion of incompatible blood, posing serious risks to the patient.

Other choices do not specifically indicate an immune response against red blood cells. Rouleaux formation occurs due to the stacking of red blood cells, often related to increased plasma proteins, and does not involve an immune reaction. Hemolysis refers to the destruction of red blood cells, which can result from various mechanisms but is not directly an interference caused by immune response in crossmatching. Incompat