In vitro testing using immunocap provides reliable assessment of sensitizing patterns to local allergens in patients with rhinitis/asthma

Abstract

Background: Bronchial asthma affects over 300 million people worldwide and half of these patients have underlying allergic disease. Accurate identification of allergen triggers will help identify patients that may benefit from immunotherapy. Objective: The objective of this study was to understand whether in vitro testing provides accurate identification of suspected local allergens in our patients. Methods: A retrospective study was conducted on patients between 2015 and 2016 with persistent mild/moderate-severe rhinitis/asthma referred for aeroallergen sensitization tests. Total immunoglobulin E (IgE) and allergen-specific IgE levels were done using Phadia 100 (Thermo Fisher Scientific). Descriptive statistics were done using Microsoft Excel and nonparametric statistics using MedCalc software V18. Results: A total of 106 patient records (including 30 children) were analyzed. The median total IgE during 2015 (n = 38) was 402 kU/L (interquartile range [IQR] 25–75, 102–871 kU/L), while for 2016 (n = 68) was 509 kU/L (IQR 25–75, 131–1245 kU/L) (standard deviation comparison nonsignificant, P = 0.536). Thirty of 106 patients (28.3%) had no aeroallergen sensitizations. Allergen-specific IgE levels revealed that the highest sensitization rate was to house dust mites (both Dermatophagoides pteronyssinus and Dermatophagoides farinae), followed by cockroach and ragweed pollen (homologous to Parthenium hysterophorus). Median IgE level among 30 children was 511 kU/L (IQR 25–75 51.8–1688 kU/L). Almost 60% children were sensitized to house dust mites. Twelve of 30 children (40%) were polysensitized (i.e., specific IgE >0.35 kUA/L to ≥4 allergens) with 30% sensitized to P. hysterophorus. Mold sensitivity was 10% in both the years studied. Conclusions: ImmunoCAP method provides reliable assessment of sensitizations even for local allergens. House dust mite, cockroach, and Parthenium allergens appear to be important predictors of asthma morbidity not only among adults but also among children in Eastern India. Immunotherapy with house dust mites may prove beneficial in selected patients.