The Relationship Between Fractional Exhaled Nitric Oxide And Peripheral Blood Eosinophils And Allergen Specific IgE In Asthmatic Patients

BackgroundFractional exhaled nitric oxide(FeNO)is an inflammatory molecule exhaled from the lungs.It is an internationally recognized and A-level evidence-based molecularmarkerofairwayinflammation.FeNOmeasurementisa real-time,quantitative,non-invasive,simple and safe tool for evaluating airway inflammatory diseases,which has been widely used for the detection of respiratory diseases such as asthma.Asthma is a multifactorial(heterogeneous)disease characterized by chronic airway inflammation.Its two main characteristics are symptoms of wheezing,shortness of breath,chest tightness and cough,and the symptoms and degree changing over time;the limited breathing air flow is variable.Asthma can be caused by infection,exercise,smoking and other factors.Allergens is an important factor in the development of asthma.The cell reaction mediated by IgE is the main mechanism,which can cause smooth muscle contraction,increased mucus secretion,increased vascular permeability and inflammatory cell infiltration.Serum allergen specific IgE(sIgE)and total IgE(TIgE)are closely related to allergic diseases,their detection is also necessary.Due to the existence of heterogeneity,various factors should be taken into account.For chronic respiratory diseases with unknown etiology,compared with pulmonary function,Fe NO is more accurate for diagnosing asthma.The latest American Thoracic Society(ATS)guidelines emphasize the value of FeNO in the diagnosis of eosinophilic asthma and suggest using FeNO thresholds for the diagnosis.A number of studies have shown that FeNOishelpfulinthedetectionandidentificationofairway hypersensitivity/eosinophilic inflammation in asthmatic patients.There is a correlation between IgE and peripheral blood eosinophils(EOS),which can be used to monitor the degree of airway inflammation,predict the sensitivity of hormone therapy,and evaluat the efficacy of hormone therapy.With the widespread application of FeNO,more clinical studies are needed to evaluate and analyze it,making it an ideal tool for diagnosing asthma.ObjectiveTo observe the expression level of FeNO and explore the correlation and clinical significance between Fe NO?serum allergen IgE and peripheral blood EOS in asthmatic patients.Methods129 patients diagnosed mild asthma who attended the First Affiliated Hospital of Zhengzhou University between October 2016 and October 2017 was collected,According to the asthma prevention and treatment guideline in 2016,Comprehensive information was recorded about the observed subjects with mild asthma,and general clinical data including sex,age,height,weight,smoking history,lung function,Symptoms and signs,complications were recorded.FeNO values were measured firstly in all patients,followed by lung function tests.Peripheral blood EOS counts,allergen sIgE and total IgE levels were examined,analyze the correlation between FeNO and peripheral blood EOS counts and serum allergen IgE in asthmatic patients.Ststistical anaysis runed by SPSS21.0 software.the symmetric distribution data was expressed as?x±s,the asymmetric distribution data was expressed as median(inter-quartile range).For the skewed distribution of quantitative data,the comparison between two independent samples using the Wilcoxon test,Krskal Wallis test was used among comparision of groups independent samples.Correlation was analyzed by Pearson product moment or Spearman rank correlation.Level of the test?=0.05Results1.Among the 129 asthma patients,there were 63 males and 66 females,with an average age of(48.58±13.07)years.There were 92 patients with FeNO?25 ppb,37patients with FeNO<25 ppb,and the average FeNO level was 42(53)ppb.The average number of EOS counts was[0.24(0.38)]×10~9/L,there were 35 patients with elevated EOS counts,85 patients with positive serum sIgE and 44 patients with negative serum IgE.Serum TIgE in 62 patients was less than 100 IU/mL,TIgE in40 patients was 100-200 IU/mL,and TIgE in 27 patients was more than 200 IU/mL.2.According the allergens,129 asthmatic patients were divided into four groups,aeroallergens group wiht 34 patients,food allergens group with 27patients,aeroallergens and food allergens group with 24 patients,and negative sIgE group with 44 patients.There was no significant difference in age,sex,height,weight,and BMI between four groups.The difference in FeNO levels between the four groups was statistically significant(P<0.05).FeNO levels in the aeroallergens group and the aeroallergens and food allergens group were higher than those in the group with negative sIgE.3.There was a significant correlation between FeNO level and EOS counts in peripheral blood,and there was a positive correlation,r=0.452,P<0.05.With the increase of serum TIgE concentration,FeNO levels also increased,P<0.05,the difference was statistically significant.4.Among allergens,dust mites are the most common allergen and there are 27casesl.Among them,18 cases are only allergic to dust mite.The first allergen of food allergens was egg,with 20 cases.There was a positive correlation between FeNO values and sIgE of dust mites in asthmatic individuals(r=0.802,P=0.001).There was no significant correlation between FeNO values and egg sIgE in asthmatic patients,r=0.107,P>0.05.Conclusions1.FeNO levels in asthmatic patients are significantly higher.2.FeNO values in asthmatic patients are correlated with EOS counts in peripheral blood,which can reflect the eosinophilic inflammation of the airway to a certain extent.3.The level of FeNO in asthmatic patients is closely related to the type and concentration of allergens.FeNO measurement combined with IgE detection have great significance in asthmatic patients.