Detection of platelet-leukocyte aggregates in nasal polyp tissue. (A) H&E staining of nasal polyp tissue from a subject with AERD shows many eosinophils (black arrowheads). (B) Immunofluorescent staining of the same tissue shows leukocytes (green, CD45⁺) with adherent platelets (red, CD61⁺; white arrowheads). Photographs are shown at 400× magnification. (C) Total numbers of CD45⁺ cells that colocalized with CD61. (D) Percentages of CD45⁺ cells that colocalized with CD61 in the nasal polyp tissue from aspirin-tolerant controls with sinusitis (n = 4) and subjects with AERD (n = 6). Data are expressed as mean + SD.