The significance of eosinophils in the correlation of upper and lower airway inflammation in patients with chronic rhinitis

Abstract

Objective: To explore the predictor of lower airway inflammation among the index of nasal inflammation by investigating the expression and association of eosinophils (EOS) in the upper-lower airways and blood of patients with chronic rhinitis. Methods: A total of 162 patients with allergic rhinitis (AR), 117 patients with non-allergic rhinitis (NAR) and 104 controls were enrolled from June 2010 to December 2013 from General Hospital of Eastern Theater Command, People's Liberation Army. All subjects were required detailed medical history collection and nasal resistance measurement. Skin prick test (SPT), blood total immunoglobin E (tIgE) and blood EOS, nasal lavage and induced sputum EOS, nasal provocation and bronchial provocation test (NPT, BPT), nasal and forced exhaled nitric oxide (NNO, FeNO) were performed in all patients. One-way analysis of variance was used for comparison between groups. LSD t test or Mann-Whitney U test was used for comparison between the two groups. Pearson or Spearman related parameter test was used for correlation analysis. Results: The nasal lavage EOS, NNO, induced sputum EOS, FeNO, blood EOS and tIgE were higher in the AR group than that in the NAR group (3.70[1.20, 14.23]/200 HP vs 1.40[0.20, 3.40]/200 HP, 673.50[466.80, 936.00] ppb vs 455.80[248.10, 705.60] ppb, 2.97[0.00, 10.63]% vs 1.00[0.23, 2.00]%, (49.28±26.37)ppb vs (34.07±19.11)ppb, 4.00[2.00, 7.00]% vs 2.00[1.00, 5.00]%, 208.01[61.70, 387.50] IU/ml vs 43.30[19.00, 122.00] IU/ml, F or χ(2) value was 11.442, 19.440, 70.727, 69.449, 47.453, 46.525, respectively, all P<0.05). But there was no significant difference in nasal resistance, NPT and BPT between the two groups. Nasal lavage EOS in AR group and NAR group was correlated with induced sputum EOS, FeNO, tIgE and blood EOS (r value of AR group was 0.448, 0.202, 0.159, 0.321, r value of NAR group was 0.442, 0.268, 0.268, 0.334, respectively, all P<0.05), but not with BPT. After adjustment for gender, age, height and weight, nasal EOS was positively correlated with sputum EOS. Multiple linear regression analysis showed that nasal EOS, blood EOS and SPT were factors affecting sputum EOS levels. The optimal threshold for nasal EOS to determine induced sputum EOS was 3.30/200 HP by (receiver operating characteristic,ROC) analysis. Conclusion: The nasal EOS is correlated with multiple lower airway and systemic inflammatory markers, and is a risk factor for the induced sputum EOS, which can be used as an inflammation biomarker to predict the lower air inflammation.