Cysteinyl leukotrienes in chronic hyperplastic rhinosinusitis

Our study was designed to demonstrate that, similar to asthma, eosinophilic chronic rhinosinusitis is a disease characterized by activation and the expression of cysteinyl leukotrienes (LTs).

Nasal polyp tissue was evaluated from 28 consecutive individuals undergoing elective polypectomy in whom neutrophils were not present on pathologic examination. Tissue was analyzed for pathosis with particular attention to the presence of eosinophils. Patients with moderate to high levels of mucosal eosinophils were classified as having eosinophilic rhinosinusitis (ECRS). Those with few or absent mucosal eosinophils were classified as having noneosinophilic rhinosinusitis (NECRS). Cysteinyl LTs were quantified by a sensitive competitive enzyme immunoassay, and the levels of cysteinyl LTs were compared in the groups.

There were 20 patients with ECRS and 8 patients with NECRS. Cysteinyl LTs were identified in polyp tissue from 24 of 28 subjects and were >5 pg/gm tissue in 15 of 28. The average level of LTC(4) in patients with few mucosal eosinophils was 38.3 pg/g. The average amount in those with moderate to large amounts of mucosal eosinophils was 36.7 pg/g. There was no significant difference between the 2 groups.

ECRS and NECRS can be considered diseases of excessive expression of cysteinyl LTs. LT expression occurs in patients who demonstrate few or no mucosal eosinophils, which indicates that cell lines other than eosinophils may be responsible for LT production in chronic rhinosinusitis.