The Expression Of BDNF In Allergic Rhinitis And Its Efficacy Evaluation On Subcutaneous Immunotherapy With House Dust Mite

Background and objectiveAllergic rhinitis(AR)is a type Ⅰ allergic disease mediated by allergen stimulation and immunoglobulin E(IgE),and is one of the most common chronic diseases worldwide."As the first-line treatment for AR,ASIT can improve the body’s abnormal immune response,achieve good symptom control,improve quality of life,and stop disease progression.ASIT,as the first-line treatment for AR,can improve the body’s abnormal immune response,achieve good symptom control,improve quality of life,and stop disease progression,and the more commonly used treatment routes are subcutaneous immunotherapy(SCIT)and sublingual immunotherapy(SLIT).Although ASIT is widely used,there is a lack of biomarkers that can effectively predict its efficacy,and further research is needed.Recent studies have revealed that BDNF may play an important role in allergic diseases and may serve as a biological marker to predict the severity of allergic asthma.The aim of this study was to confirm whether peripheral serum BDNF could be an objective indicator for evaluating the severity of allergic rhinitis and the efficacy of SCIT in allergic rhinitis.MethodsPart Ⅰ:(1)102 AR patients attending the Department of Otorhinolaryngology of the Second Hospital of Shandong University and 78 controls without symptoms of allergic rhinitis and with negative allergen tests were collected.AR patients with positive(≥ 0.35 kUA/L)levels of at least one specific immunoglobulin E(sIgE)according to the criteria of the Guidelines for the diagnosis and treatment of allergic rhinitis(Tianjin,2015)were collected;(2)Serum BDNF levels of AR patients and controls were measured by enzyme-linked immunosorbent assay(ELISA)kits;(3)Routine peripheral blood eosinophil counts and eosinophil percentages of AR patients and controls were recorded.(4)Immuno CAP IgE antibody test system to detect total serum IgE levels in AR patients and controls and serum Der-p sIgE and Der-f sIgE levels in AR patients;(5)Record the nasal symptom scores of AR patients by questionnaire(including nasal congestion,runny nose,sneezing(including nasal congestion,runny nose,sneezing,nasal itching and total nasal symptom scores(TNSS))were recorded by questionnaires and the patients’ comprehensive allergy symptoms were scored using visual analogue scale(VAS);(6)To analyze the differences in serum BDNF expression levels between AR patients and controls;(7)To analyze the correlation between serum BDNF expression levels and the above-mentioned subjective symptom scores and objective indicators in AR patients.Part Ⅱ:(1)To enrol1 62 AR patients who visited the Department of Otolaryngology at the Second Hospital of Shandong University between 2019 and 2022 and completed 3 years of standard subcutaneous immunotherapy(SCIT).Inclusion criteria:patients with typical signs and symptoms of allergic rhinitis,positive d1 sIgE and/or d2 sIgE levels(≥0.35kUA/L)and agreed to receive SCIT treatment;(2)Serum BDNF levels measured by ELISA kits at 4 time points before,1,2 and 3 years after treatment;(3)Immuno CAP IgE Antibody Test System detects serum total IgE,Der-p sIgE,Der-f sIgE levels at 4 time points;(4)Nasal symptom scores,VAS,Rhino-conjunctivitis quality of life questionnaire(RQLQ)and medication scores were administered at four time points;(5)To analyze the changes in the above subjective symptom scores and objective indicators at four time points;(6)To analyze the correlation between changes in serum BDNF levels and changes in the subjective symptom scores and objective indices described above.ResultsPart Ⅰ:(1)Serum BDNF expression levels were significantly higher in AR patients than in controls(P<0.001).(2)Serum BDNF expression levels in AR patients showed a significant positive correlation with nasal congestion(P<0.001),nasal itching(P<0.001),TNSS(P<0.001)and VAS score(r=0.746,P<0.001).(3)Serum BDNF levels in AR patients were positively correlated with eosinophil percentage(r=0.258,P<0.01)and eosinophil count(r=0.256,P<0.01).(4)There was no significant correlation between serum BDNF and total IgE,Der-p sIgE and Der-f sIgE in AR patients.Part Ⅱ:(1)Serum BDNF levels in SCIT patients decreased year by year during the 3 years of treatment.(2)SCIT patients had significantly down-regulated d1 sIgE levels after 3 years of treatment compared to baseline levels.(3)The ratio of dl sIgE/total IgE was significantly downregulated in SCIT patients after 3 years of treatment compared to baseline levels.(4)SCIT patients showed significant improvement in nasal congestion,runny nose,sneezing,pruritus,TNSS,VAS,RQLQ and medication scores after 3 years of treatment.(5)The decrease in serum BDNF expression level was positively correlated with the improvement of nasal congestion(r=0.464,P<0.01),nasal itching(r=0.334,P<0.01)and medication score(r=0.349,P<0.01)after 3 years of treatment in SCIT patients.(6)The decreasing level of serum BDNF in SCIT patients was consistent with the improvement of runny nose,sneezing,TNSS,VAS,RQLQ and the trend of d1 sIgE and d1 sIgE/total IgE.ConclusionSerum BDNF levels were significantly elevated in AR and showed a significant positive correlation with nasal symptoms such as nasal congestion,nasal itch,TNSS and VAS,as well as with the levels of peripheral blood eosinophils involved in the allergic inflammatory response.The year-to-year decrease in serum BDNF expression levels over the 3 years of SCIT and the decrease in serum BDNF levels were significantly and positively correlated with improvement in nasal symptoms including nasal congestion,nasal itch,and medication scores.Therefore,serum BDNF expression levels may not only be used as an indicator to assess the severity of allergic rhinitis,but also as a promising biomarker to evaluate the efficacy of SCIT.