IgE and IgG4 Repertoire in Asymptomatic HDM-Sensitized and HDM-Induced Allergic Rhinitis Patients

<b><i>Introduction:</i></b> Asymptomatic sensitization is defined as the presence of positive skin prick test (SPT) and/or positive serum allergen-specific IgE in the absence of clinical allergic symptoms. Currently, there is no convincing explanation why some people with positive allergen tests do not show symptoms. We aimed to investigate the house dust mite (HDM)-specific IgE and IgG4 repertoire in asymptomatic HDM-sensitized subjects and HDM-induced allergic rhinitis (AR) patients. <b><i>Methods:</i></b> A total of 48 subjects sensitized to HDM were included in this study: 27 had AR with/without asthma (symptomatic group), and 21 had no allergic symptoms (asymptomatic group). Six healthy individuals served as control group. Peripheral blood samples were collected for serum IgE and IgG4 assay and basophil activation tests (BATs). IgE and IgG4 assay included antibodies to <i>Dermatophagoides</i> (<i>Der</i>) <i>p1</i>, <i>2</i>, <i>7</i>, <i>10</i>, <i>21</i>, <i>23</i>, and <i>Der f1</i>, <i>2</i>. <b><i>Results:</i></b> AR patients had a larger wheal diameter of SPT (7.0 vs. 3.0 mm, <i>p</i> &#x3c; 0.0001) and a higher specific IgE to <i>Der p</i> (15.50 vs. 0.70 KU/L, <i>p</i> &#x3c; 0.0001) than asymptomatic subjects. They also showed more frequent sensitization to <i>Der p1</i> and <i>Der p2</i> (both <i>p</i> &#x3c; 0.05). However, the total IgE and specific IgG4 did not differ significantly between the 2 groups. The basophil activation response after being stimulated with HDM was observed to be higher in AR patients (all <i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> There are differences in SPT, serum-specific IgE to <i>Der p</i>, component allergen <i>Der p1</i> and <i>Der p2</i> level and BAT between AR patients and asymptomatic subjects sensitized to HDM. IgG4 alone cannot differentiate asymptomatic individuals from AR patients.

House Dust Mite Allergy and the Der p1 Conundrum: A Literature Review and Case Series

The house dust mite (HDM) is globally ubiquitous in human habitats. Thirty-two allergens for Dermatophagoides farinae and 21 for Dermatophagoides pteronyssinus have been detected so far. The present minireview summarizes information about the role of Der p 1 as a key coordinator of the HDM-induced allergic response and reports on a series of Italian patients who are allergic to HDMs. We studied the specific IgE profiles in a population of patients with allergic asthma and rhinitis screened for specific immunotherapy (SIT) for HDM allergies, with the aim of obtaining insights into the pathogenic role of Der p1. Patients co-sensitized to other airborne allergens showed a higher prevalence of asthma (9/12 (75%) vs. 2/7 (29%); p < 0.05) than did HDM mono-sensitized patients. The latter group showed higher Der p1 concentrations than that of the co-sensitized group (p = 0.0360), and a direct correlation between Der p1 and Der p2 (r = 0.93; p = 0.0003) was observed. In conclusion, our study offers insights into the role of Der p1 in a population of patients with allergic rhinitis and asthma who were candidates for SIT. Interestingly, Der p1 positivity was associated with bronchial asthma and co-sensitization.

The Dermatophagoides pteronyssinus Molecular Sensitization Profile of Allergic Rhinitis Patients in Central China

Background House dust mites (HDMs) are the major aeroallergens in patients with rhinitis and/or asthma in China. However, the molecular sensitization of HDM is varied in different regions. Objective To investigate the Dermatophagoides pteronyssinus ( Der p) molecular sensitization profile of allergic rhinitis (AR) patients in Central China. Methods AR patients with positive skin prick tests to Der p were enrolled in our study. Specific immunoglobulin E (sIgE) for Der p, Dermatophagoides farinae ( Der f), Acarus siro ( Aca s), Blomia tropicalis ( Blo t), and Der p components Der p1, Der p2, and Der p10 were measured in all patients. Results A total of 130 patients were included. The overall prevalence of positive serum sIgE was 99.2% for Der p, 98.5% for Der f, 81.5% for Aca s, 83.1% for Blo t, 71.5% for Der p1, 64.6% for Der p2, and 11.5% for Der p10. HDM-AR patients with asthma displayed significantly higher concentrations of sIgE to Der p, Der f, Der p1, and Der p2 than did those without asthma ( P < .001). The prevalence of asthma in HDM-AR patients was higher among the patients sensitized to both Der p1 and Der p2 (62.8%) than those sensitized to only 1 allergen ( Der p1 26.7% or Der p2 16.7%; P < .05) or nonsensitized to Der p1 and Der p2 (19.4%; P < .001). Conclusion Der p has high cross-reactivity with other mite species. Der p1 and Der p2 are the major components to induce Der p sensitization among AR patients in Central China. Sensitization to both Der p1 and Der p2 may be a risk factor for developing asthma in HDM-AR patients.