Management of nonimmediate hypersensitivity reactions to drugs

摘要

The denomination "nonimmediate hypersensitivity" explicitly refers to idiosyncratic, type B, reactions mediated by a drug-specific immune response belonging to types II, III, and IV of the classification proposed by Coombs and Gell.Type II reactions, antibody-mediated reactions, are considered responsible for a variety of drug-induced blood dyscrasias (eg, thrombocytopenia).2 Type III reactions, involving depositions of immune complexes, are definitely the cause of serum-sickness, a reaction that is quite rare nowadays. For "serum-sickness-like syndromes" and drug-induced vasculitis, often quoted as other examples of type III hypersensitivity, the pathomechanisms are actually more complex, with T cells playing a role and drug-specific antibodies being rarely detected. Most nonimmediate reactions to drugs are actually type IV, delayed, T-cell-mediated reactions.