Aspirin Idiosyncrasy in Systemic Mast Cell Disease: A New Look at Mediator Release During Aspirin Desensitization

To report the clinical responses and mediator-release profiles of an aspirin-sensitive man with systemic mast cell disease during aspirin desensitization. We quantified the release of six mediators during aspirin desensitization. Although aspirin was administered cautiously with an initial dose of 20 mg, successful aspirin desensitization necessitated complete monitoring and resuscitation capabilities of a medical intensive-care unit for 4.5 days because of frequent, severe anaphylactoid responses. To our knowledge, this is the first report of a pronounced increase in plasma levels of the vasodilator peptide calcitonin gene-related peptide during episodes of aspirin-induced hypotension. Increases in plasma levels of calcitonin and serum levels of tryptase paralleled those of calcitonin gene-related peptide, but plasma levels of calcitonin remained increased for up to 18 hours. Urinary excretion ofhistamine and I-methyl-4-imidazoleacetic acid also showed precipitous, although delayed, increases. Excretion of the prostaglandin D₂ metabolite 11β-prostaglandin F _2α: followed a bimodal pattern during aspirin desensitization; after severe hypotensive responses, the maximal value was more than 490,000 pg/mL, but the level decreased to less than 100 pg/mL after therapeutic serum levels of salicylate were attained. These data suggest that the hypotensive responses to aspirin in some patients with systemic mast cell disease may result from the combined effects of several mediators.