Pro-haptens

Metabolic activation of a,/ -unsaturated oximes, such as 46, leads to the conclusion that this class of unsaturated oximes are pro-haptens. They can undergo epoxidation that eventually produces reactive nitroso intermediates which act as strong contact sensitizers . Here, the oxime function plays a major role in the chemical activation that results in the reactive nitrosoaUcenes. It was further pointed by the authors that oximes can be hydrolyzed in vivo to the corresponding carbonyl compounds which are potential allergens. 

Sometimes, as with sulfamethoxazole, the drug itself does not react with proteins or peptides to induce an immune response. Rather, intracellular metabolism of the parent drug forms the metabolite, sulfamethoxazole-nitroso, which binds covalently to proteins and peptides and induces immunogenicity [41]. This represents a drug that is a pro-hapten, which is immunologically reactive and able to bind to MHC complexes on APCs only after it is metabohzed. 

Gerberick GF, Troutman JA, Foertsch LM, Vassallo JD, Quijano M, Dobson RL, Goebel C, Lepoittevin JP (2009) Investigation of peptide reactivity of pro-hapten skin sensitizers using a peroxidase-peroxide oxidation system. Toxicol Sci 112 164-174... 

Nineteen additional antigens also failed to react with any of their myeloma sera. Antigens tested included thirteen different haptens, pneumococcal polysaccharide, and four mycoplasma antigens. The authors contrasted their results with those obtained with mouse myeloma pro-... 

---