Time Course Of Serum Inhibitory Activity For Facilitated Allergen–IgE Binding During House Dust Mite Immunotherapy And Its Relationship With Clinical Efficacy

Setion ? Establishment and Validation of a Method on the IgE-facilitated Allergen Binding Assay Objective:To establish and validate a method of the IgE-facilitated allergen binding?IgE-FAB?assay with house dust mites and measure the inhibitory activity for facilitated allergen–IgE binding from the serum collected from the patients who received the house dust mites specific immunotherapy?HDM-SIT?.Methods:According to the methodology from the International Conference on Harmonization?ICH?,the IgE-facilitated allergen binding assay with house dust mites was established and the dependence,the variability between intra-assay and inter-assay,repeability,sensitivity,linearity,and robustness were validated.Patients who had mild to moderate asthma and/or rhinitis and received standardized HDM-SIT over one year was chose to research.The combined clinical and medication scores were used to identify true positive?TP?and false positive?FP?results.In this evaluation of clinical sensitivity and specificity,relative binding data from the IgE-FAB assay were used to generate a receiver operator characteristic curve.Result:The optimal B cell binding occurred between 1 and 5 ?g/ml of HDM allergen.Optimal relative B cell binding occurred at 2?g/ml of HDM allergen with SIT seurm and the rusult is 35.0±22.0%.The percentage allergen–IgE binding to B cells is strongly correlated with level of specific Ig E from indicater serum?r=0.898,p<0.001?.The intra-and inter-assay variability data shows that the total coefficient of variation was 10.28% and 11.70% for positive quality control serum and ngative quality control serum.Conclusion:In summary,the IgE-FAB assay on HDM is reproducible,robust,sensitive and specific and has the potential to be used as a tool for monitoring inhibitory antibody responses induced by allergen-specific immunotherapy and predicting the clinical efficacy,and to be used as the immunological markers for laboratory detection during HDM-SIT.Setion ? Time Course of serum Inhibitory Activity for Facilitated Allergen–IgE Binding during House Dust Mite Immunotherapy and its Relationship with Clinical Efficacy Objective:To illustrate time course of serum inhibitory activity for facilitated allergen–IgE binding during house dust mite immunotherapy and its relationship with clinical efficacy.Methods:Fifty-two patients with mild to moderate asthma and/or rhinitis who received standardized HDM-SIT over three years in the Department of Allergy and Immunology,the First Affiliated Hospital of Guangzhou Medical University were enrolled while thirty one patients with mild to moderate asthma/or rhinitis who received routine medication therapy were as the control group.Asthma and rhinitis symptom scores and medication scores were recorded.The percentage of predicted value of forced expiratory volume with in 1 second?FEV1%?and airway hyperresponsiveness?AHR?were measured.The concentrations of HDM sIgE?Der p sIgE?,dermatophagoides farinae s IgE?Der f sIgE?,total IgE and HDM s IgG4 in serum were measured and IgE-FAB assay was carried out before and at the 4th,12 th,16th,52 nd,104th and 156 th week during the treatment.We analyzed the changes of the clinical parameters and immunological markers and the correlations among Der p sIgG4,the percentage relative binding to allergen–IgE complexes and the combined clinical and medication scores.Results:The combined clinical and medication scores decreased significantly at 12^th,16^th,52^nd,104^th and 156^th week during the treatment than that before treatment in the SIT subjects?P<0.05?,which also appeared in the control group.Compared with the control group,the combined clinical and medication scores at 52^nd,104^th and 156 th week during SIT decreased significantly?P<0.05?.FEV1% and FVC% did not showed significant difference between the two groups and before and during treatment?P>0.05?.The grade of AHR decreased significantly at the 52 nd week?1.50±1.37?,the 104 th week?1.50±1.34?,the 156th?11.18±1.08?during treatment in SIT subjects compared with the treatmen before?p<0.05?,while it was not found such changes in control group.The sIgG4?AU/ml?level in serum at 12th?844.03±1103.69?,16th?4454.37 ± 4417.18?,52nd?916031.87 ± 21457.52?,104th?27522.23 ±29689.03?,156th?31593.92±41203.70?was significantly higher than that treatment before?430.67±573.38?in SIT subjects?p < 0.01?and the sIgG4 level increased constantly from 12 th weeks to 104 th weeks,but there was no significant differences between 104 th and 156 th week?p>0.05?,whereas no changes were found in the control group.IgG4 significantly higher than the control group at 16 th,52nd,104 thand 156th week in SIT subjects?p<0.001?.The percentage relative binding to allergen–IgE complexes decreased significantly at week 16?71±22%?,52?45 ±22%?,104?35±18%?,156?31±15%?in SIT group,compared with the treatment before?112±24%?and decreased constantly from 16 th weeks to 104 th weeks,but there was no significant differences between 104 th and 156 th week?p>0.05?,while it was not found such changes in control group.The percentage relative binding to allergen–IgE complexes significantly lower than the control group at 16 th,52nd,104 th and 156 th week in SIT subjects?P<0.001?.The level of Der p sIgE in serum decreased significantly at the 52 nd week?71.25±103.75?the 104 th week?73.79±117.67?,the 156 th week?62.75±86.50?during treatment in SIT subjects compared with the treatmen before?96.98±126.98??p<0.05?,whereas no changes were found in the control subjects,which also appeared on the level of Der f s IgE.The percentage relative binding to allergen–IgE complexes associated with s IgG4 at updosing phase and maintenance phase?p<0.001?.The combined clinical and medication scores associated with the concentration of Der p s IgG4,the percentage relative binding to allergen–IgE complexes on linear correlation at maintenance phase?p<0.05?,while it was not found such correlation in control group at updosing phase?p>0.05?.Conclusion:The level of sIgG4 and inhibitory activity were increased in the early treatment of House dust mites SIT,while the level of s IgE could decreased at the long –term maintain phase.The level of sIgG4 and inhibitory activity at the maintain phase correlate closely with clinical response rather than updosing phase.maintain phase may be the main phase in the formation of a SIT induction of immune tolerance.