Cephalosporin can cause a positive direct antiglobulin test due to which mechanism?

The mechanism by which cephalosporin can cause a positive direct antiglobulin test (DAT) is best explained by the concept of drug-dependent antibodies reacting in the presence of a drug. When cephalosporins are administered, they can induce a specific immune response where antibodies are formed that only react when the drug is present. This means that the antibodies are not continuously binding to the red blood cells; instead, they require the presence of the drug to form stable complexes with the drug-modified cells.

In this context, the binding of these antibodies is contingent upon the cephalosporin being present, which is crucial for the agglutination to occur and subsequently yield a positive DAT. This mechanism is often observed in hemolytic anemias associated with certain medications, where the drug modifies the red blood cells in a way that makes them appear foreign to the immune system.

Other mechanisms, such as drug-independent autoantibody production or nonimmunologic protein adsorption, represent different processes that do not accurately describe the action of cephalosporins leading to a positive DAT. In particular, while nonimmunologic protein adsorption can produce a positive DAT, it does not involve the formation of specific antibodies, which is