Cysteinyl leukotrienes play a disease-regulating role in rhinosinusitis and asthma, particularly aspirin-sensitive disease. They act through 2 G-protein coupled receptors termed cysteinyl leukotriene type 1 receptor (cysLT₁) and cysteinyl leukotriene type 2 receptor (cysLT₂). We previously compared expression of cysLT₁ on mucosal leukocytes in patients with aspirin-sensitive and aspirin-tolerant rhinosinusitis.

To compare expression of cysLT₁ and cysLT₂ on leukocytes, mucus glands, and epithelium in 32 patients with chronic polypoid rhinosinusitis (21 aspirin-sensitive, 11 aspirin-tolerant) and 9 normal controls.

Total numbers of CD45⁺ leukocytes, percentages of these cells expressing cysLT₁ or cysLT₂, and percentages of the total epithelial and glandular areas expressing cysLT₁ or cysLT₂ were measured in sections of nasal biopsies by using immunohistochemistry and image analysis.

The percentages of mucosal CD45⁺ leukocytes expressing cysLT₁ were significantly (P < .0001) elevated in the aspirin-sensitive but not the aspirin-tolerant patients compared with the controls. In contrast, the percentages of leukocytes expressing cysLT₂ did not differ significantly in the 3 groups. On epithelial and glandular cells, expression of cysLT₂ significantly exceeded that of cysLT₁ in both the patients with rhinosinusitis and the controls (P ≤ .004), although there was no significant difference in the expression of either receptor in the patients with rhinosinusitis (aspirin-sensitive or aspirin-tolerant) and the controls.

Although cysLT₁ expression predominates on inflammatory leukocytes in patients with aspirin-sensitive rhinosinusitis, the effects of cysteinyl leukotrienes on glands and epithelium may be mediated predominantly through cysLT₂. This has potentially important therapeutic implications.