Association of house dust mite-specific IgE with asthma control, medications and household pets

BACKGROUND: Evidence is conflicting regarding the effectiveness of creating a low-allergen environment or reducing allergen exposure to control asthma exacerbations. OBJECTIVE: This study determined the association of house dust mite (HDM)-specific IgE levels with asthma symptom control, selected medications, family history of allergic disease, and exposure to second-hand smoke and household pets. METHODS: Serum samples from 102 doctor-diagnosed allergic asthma patients and 100 non-atopic controls were subjected to enzyme-linked immunosorbent assay using the HDM species Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), and Blomia tropicalis (Bt) allergens. Point-biserial correlation coefficient, Pearson R correlation, and logistic regression analyses were used to determine association of HDM-specific IgE levels with the abovementioned variables. RESULTS: Of the 102 cases, 38.24%, 47.06%, and 33.33% were sensitized to Bt, Df, and Dp, respectively. Sensitized patients showed greater probability [Bt (OR = 1.21), Df (OR = 1.14), and Dp (OR = 1.35)] to manifest symptoms than those who were not. Obtained p-values [Bt (p = 0.73), Df (p = 0.83), and Dp (p = 0.59)], however, proved that HDM-specific IgE levels had no significant contribution in predicting or explaining occurrence of asthma symptoms. Bt- and Df-specific IgEs showed moderately weak but significant relationship with bambuterol HCl and expectorant, respectively. Patients currently on said medications registered higher HDM-specific IgE levels than those who were not. No significant correlation between IgE levels and family history of allergic disease or with exposure to second-hand smoke was seen. Dp-specific IgE levels of patients exposed to household pets were significantly lower compared to those without exposure. CONCLUSION: This study proves that sensitization to Bt, Df, and Dp allergens is not significantly associated with asthma symptoms and control. Although cases were shown to be sensitized to HDMs, their current medications were at least effective in controlling their asthma symptoms.