Objective: To analyze the immunological pattern of nasal polyposis in patients with and without allergy, the percentages of CD4+ cellsexpressing intracellular interferon-γ and interleukin-4 (T helper [TH] type 1 and 2 cells) were measured by fl ow cytometry in samples from patients with nasal polyps.

Methods: Samples from 32 patients (16 atopic, 16 nonatopic) were studied. The fresh nasal polyp samples were prepared in single cell suspension for fl ow cytometry. Eosinophils were counted in hematoxylin-and-eosin–stained sections of all the samples.

Results: TH1 cells were predominant in all the nasal polyps, with no significant differences in the mean (±SD) percentages of TH1 cells between the 2 groups (46.28% ± 14.95% vs 38.25% ± 9.16%, P > .05). The mean percentage of TH2 cells in the polyps from the atopic patient group was signifi cantly greater than in polyps from nonatopic group (7.34% ± 2.54% vs 0.63% ± 0.31%, respectively; P < .01); the eosinophil count was signifi cantly higher in atopic patient polyp samples (54.5 ± 15.76 eosinophils/HPF) than in nonatopic ones (14.38 ± 5.6 eosinophils/HPF, P < .01). The mean percentage of TH1 cell correlated with eosinophil count in the polyp samples overall (r = 0.80, P < .01).

Conclusions: TH1 cells were predominant in nasal polyp tissue. Polyps from atopic patients had more TH2 cells and eosinophils than nonatopic patients’ polyps did. Eosinophil recruitment in nasal polyposis is probably associated with TH2 cell infiltration. Nonatopic and atopic patients’ polyps have different immunological patterns.

Key words: Nasal polyps. T helper cells: TH1, TH2. Flow cytometry. Eosinophilia.