T helper cell population and eosinophilia in nasal polyps.

OBJECTIVE To analyze the immunological pattern of nasal polyposis in patients with and without allergy, the percentages of CD4+ cells expressing intracellular interferon-gamma and interleukin-4 (T helper [T(H)] type 1 and 2 cells) were measured by flow 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 flow cytometry. Eosinophils were counted in hematoxylin-and-eosin-stained sections of all the samples. RESULTS T(H)1 cells were predominant in all the nasal polyps, with no significant differences in the mean (+/-SD) percentages of T(H)1 cells between the 2 groups (46.28% +/- 14.95% vs 38.25% +/- 9.16%, P > .05). The mean percentage of T(H)2 cells in the polyps from the atopic patient group was significantly greater than in polyps from nonatopic group (7.34% +/- 2.54% vs 0.63% +/- 0.31%, respectively; P < .01); the eosinophil count was significantly 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 T(H)1 cell correlated with eosinophil count in the polyp samples overall (r = 0.80, P < .01). CONCLUSIONS T(H)1 cells were predominant in nasal polyp tissue. Polyps from atopic patients had more T(H)2 cells and eosinophils than nonatopic patients' polyps did. Eosinophil recruitment in nasal polyposis is probably associated with T(H)2 cell infiltration. Nonatopic and atopic patients' polyps have different immunological patterns.