Individual monitoring of aspirin desensitization.

BACKGROUND Patients with aspirin-sensitive rhinosinusitis, which is frequently associated with intrinsic bronchial asthma, can be desensitized by long-term treatment with oral aspirin. The exact mechanisms of this desensitization remain obscure, but modulations of the eicosanoid pathway occur and can be monitored with the help of a practicable in vitro assay on mixed leukocyte cultures. OBJECTIVE To monitor the effect of low-dose aspirin desensitization therapy, 100 mg/d, objectively by an in vitro assay. DESIGN In a prospective study, 30 patients with aspirin intolerance, who were treated following a desensitization protocol with a dose of oral aspirin of only 100 mg/d were followed up for 1 year and reassessed every 3 months clinically and in vitro. RESULTS Twenty-five patients showed a normalization of in vitro eicosanoid levels during this period, 4 showed some improvement, and 1 showed no therapeutic effect on eicosanoid release. Clinical follow-up revealed a low recurrence rate of nasal polyposis, with recurrent disease only in 4 individuals who also showed no normalization of eicosanoid release levels. Furthermore, a reduction of the average incidence of purulent episodes of sinusitis was seen after 1 year. Of 12 patients with asthma, 9 experienced marked improvement in pulmonary function. Of 16 individuals with a marked impairment of nasal breathing, 14 felt an increase of nasal patency, and 7 of 11 patients with pretreatment hyposmia had an improved sense of smell after 1 year. CONCLUSIONS Desensitization therapy in patients with aspirin-sensitive rhinosinusitis can be successfully performed with low oral doses of aspirin, and the individual course throughout the desensitization can be monitored with the help of an in vitro analysis of eicosanoid release from mixed leukocyte cultures.