INTERFERON-GAMMA EXPRESSION IN HUMAN NASAL POLYPS

One feature among nasal polyps (NPs) is the predominance of lymphocyte s and eosinophils, We hypothesize that elevated levels of interferon g amma (IFN-gamma) activate lymphocytes and eosinophils within the NP mi croenvironment. Nasal polyps were evaluated for distribution and level s of IFN-gamma in specimens from 27 patients with nasal polyposis and 4 controls. Immunohistochemical study revealed IFN-gamma staining of e osinophils, glandular cells, and epithelium (27 of 27 patients). ELISA analysis indicated elevated IFN-gamma levels in total NP tissues (25. 6 +/- 7.23 pg/mg total protein [TP]) compared with controls (16.27 +/- 6.54 pg/mg TP). Three subpopulations were identified based on IFN-gam ma levels: low IFN-gamma group (10.7 +/- 5.51 pg/mg TP) medium IFN-gam ma group (25.70 +/- 5.90 pg/mg TP); and high IFN-gamma group (52.58 +/ - 10.29 pg/mg TP). The later levels were approximately 3.5 times the c ontrol levels (P<0.0025). Patients with previous polypectomy surgery s howed higher levels of IFN-gamma compared with controls (P<0.0423). A trend was found with increased IFN-gamma levels and allergy, asthma, a nd topical steroid use.