The effect of aspirin desensitization on urinary leukotriene E4 concentrations in aspirin-sensitive asthma.

Abstract

Patients with aspirin sensitive asthma (ASA) can be desensitized to aspirin but the mechanisms by which this happens are unknown. To test the hypothesis that there may be a reduction in aspirin-induced leukotriene release following aspirin desensitization, we studied nine patients with ASA, 37 +/- 2.3 yr of age (mean +/- SEM) with a baseline FEV1 of 94 +/- 3.5%. Urinary leukotriene E4 (LTE4) and FEV1 were measured before and after ingestion of a threshold dose of aspirin leading to a 15% decrease in FEV1, and then at intervals following desensitization, when a maintenance dose of 600 mg aspirin was ingested. Prior to desensitization, the maximum decrease in FEV1 following ingestion of a threshold dose of aspirin was 15.3 +/- 3.9%, and urinary LTE4 rose from a baseline value of 235 +/- 79.4 pg/mg creatinine to 1,714 +/- 783 pg/mg creatinine at 3 h. Immediately after acute desensitization, which was performed over several days, 600 mg aspirin provoked a maximum decrease in FEV1 of only 3.3 +/- 2.4%, and urinary LTE4 increased from a baseline of 645 +/- 223 pg/mg creatinine to 1,256 +/- 456 pg/mg creatinine. Following ingestion of 600 mg aspirin for 9 +/- 3.2 mo (n = 5; chronic desensitization), urinary LTE4 rose from a basal level of 432 +/- 127 pg/mg creatinine to 749 +/- 257 pg/mg creatinine at 3 h after 600 mg aspirin, and this was accompanied by a maximum decrease in FEV1 of 7.4 +/- 4.5%. Although there was significantly less aspirin-induced LTE4 excretion after acute desensitization, substantial amounts of LTE4 were still produced without any significant change in lung function.(ABSTRACT TRUNCATED AT 250 WORDS)