House dust mites-driven allergic rhinitis: could its natural history be modified?

INTRODUCTION: Allergic rhinitis (AR) is the most common IgE-mediated disease. House dust mites (HDMs)-sensitization is the main cause of AR. HDM-driven AR is characterized by a typical natural history consisting of possible progression to asthma. Allergen Immunotherapy (AIT) is, at present, a unique treatment to modify the natural history of allergic diseases. Tablets AIT (TAIT) represents a new era in AIT. There is evidence that TAIT could prevent asthma in AR patients. AREAS COVERED: The literature search methodology was based on the articles cited by PubMed from 1980 to 2020. AIT's rationale is to restore an immunological and, consequently, clinical tolerance toward the causal allergen. The progression from rhinitis to asthma may be influenced by a relevant risk factor, such as the persistent type 2 inflammation of airways. HDMs are perennial allergens and allergen exposure is the condicio sine qua non to maintain inflammation. AIT could modify the progression toward asthma restoring physiologic immune response to the causal allergen and consequently dampening type 2 inflammation. EXPERT OPINION: Patients with HDM-driven AR are susceptible to develop asthma over time. Many studies explored this topic. Cross-sectional and longitudinal studies identified some markers which predict the risk of developing asthma. They include bronchial airflow limitation, bronchial hyperresponsiveness, type 2 inflammation, and rhinitis duration. TAIT could block this progression by acting on this vicious circle. Future studies should explore this issue using adequate methodology.

Prevalence and Clinical Characteristics of Local Allergic Rhinitis to House Dust Mites.

Local allergic rhinitis (LAR) is a localized nasal allergic response in the absence of systemic atopy. The aim of this study was to evaluate the prevalence and clinical characteristics of LAR in Korean rhinitis patients compared to allergic rhinitis (AR) and non-allergic rhinitis (NAR). A total of 304 rhinitis patients were enrolled from November 2014 to March 2016. A skin prick test, serum total and specific immunoglobulin E, and a nasal provocation test (NPT) with house dust mite (HDM) were performed on all patients. Subjects also documented changes in rhinitis symptoms before and after NPT. Seventy-four patients with nasal hyper-reactivity and 80 patients with subclinical allergy were excluded. AR was diagnosed in 69 (46.0%) patients, NAR in 75 (50.0%) patients, and LAR to HDM in 6 (4.0%) patients. The average medication score and disease duration of each group were 14.5 points and 77.6 months in AR, 12.1 point and 51.1 months in NAR, and 17.7 point and 106.0 months in LAR, respectively. There were no significant differences in the baseline nasal symptom score of the three groups. However, after NPT with HDM, the score of rhinitis, itching, and obstructive were 4.83±1.47 vs. 1.95±2.53, 3.00±2.10 vs. 1.45±2.06, and 5.50±1.38 vs. 2.57±2.84 in LAR and NAR, respectively (p<0.05). LAR patients had longer duration of disease and tended to be older and have higher medication score than other rhinitis patients.

The Investigation of the Presence of Mites in Some Served Dry Foodstuffs.

OBJECTIVE: Mites are microscopic organisms that lower the quality of life of people who are sensitive to them by causing conditions such as atopic dermatitis, allergic rhinitis, and asthma. These organisms are found in every habitat where humans live. This study was conducted to determine the presence of storage mites in dry food items. METHODS: Various food items were procured 10 times each in 300-gram samples. Mites were extracted with a Berlese funnel apparatus over Erlenmeyer flasks containing 70% alcohol placed at the end of the funnel stems for over 48 h. RESULTS: Of 25 food items examined in the study, only six were contaminated by mites. Species of the mites found were Acarus siro (34.6%), Glycyphagus domesticus (22.8%), Tyrophagus putrescentiae (16.8%), Tyrophagus spp. (7.9%), Rhizoglyphus spp. (1%), Lepidoglyphus destructor (7.9%), Cheylettus malacensis (4%), and Cheylettus spp. (2%). CONCLUSION: Although the results of the study show that the presence of mites in food items sold in open containers at open-air markets or stores was low, we suppose that they can cause important health problems for sensitive people.

Role of Predatory Mites in Persistent Nonoccupational Allergic Rhinitis.

Mites can sensitize and induce atopic disease in predisposed individuals and are an important deteriorating factor in patients with allergic rhinitis, asthma, and atopic dermatitis. Although Pyroglyphidae mites have been extensively studied, very scarce reports are available on Cheyletidae spp. especially regarding human respiratory pathology. The main objective of the present study is to investigate the clinical role of this predator mite (Cheyletus eruditus) as a respiratory antigen in a selected sensitized human population. Fifty-two adult patients were recruited from the outpatient allergy clinic to assess their eligibility for the study. The thirty-seven subjects with persistent allergic rhinitis (PAR) who fulfilled the ARIA criteria had a positive IgE response confirmed by skin prick test (SPT) to C. eruditus. Only those individuals (37/47) with a positive SPT to C. eruditus showed a positive nasal provocation test (NPT), while 10 patients with nonallergic mild-to-moderate persistent rhinitis, control group, had a negative NPT with C. eruditus. The present paper describes a new role for the predator mite Cheyletus eruditus as a respiratory allergen in a selected subset of patients in a subtropical environment afflicted with persistent nonoccupational allergic rhinitis.

Association of VDR and CYP2R1 Polymorphisms with Mite-Sensitized Persistent Allergic Rhinitis in a Chinese Population.

As recent studies have described an association between vitamin D and allergic rhinitis, we hypothesized that vitamin D pathway-related genes may be candidate genes for susceptibility to allergic rhinitis. Thus, we sought to evaluate whether polymorphisms in the vitamin D receptor (VDR) and CYP2R1 genes are associated with mite-sensitized persistent allergic rhinitis (PER) in a Han Chinese population. A hospital-based case-control study consisting of 519 patients with mite-sensitized PER and 447 healthy controls was conducted. Five single nucleotide polymorphisms (SNPs) in VDR and CYP2R1 were selected for genotyping. The genotype and allele frequencies of rs9729, rs2228570, rs1544410, and rs731236 in VDR as well as rs2060793 in CYP2R1 were not significantly associated with susceptibility to mite-sensitized PER. After stratification analyses, however, both the CT and CT/TT genotypes of rs2228570 in VDR exhibited a significantly decreased risk (CT: adjusted odds ratio (OR)=0.58, 95% confidence intervals (CI)=0.37-0.91; CT/TT: adjusted OR=0.61, 95% CI=0.40-0.93) of mite-sensitized PER, while the AA genotype of rs2060793 in CYP2R1 exhibited a significantly increased risk (adjusted OR=1.85, 95% CI=1.03-3.34) of PER in the age subgroup of <16 years old. Both the AG and AG/GG genotypes of rs731236 in VDR exhibited a significantly decreased risk (AG: adjusted OR=0.43, 95% CI=0.21-0.89; AG/GG: adjusted OR=0.46, 95% CI=0.23-0.94) of PER in the female subgroup. Analysis of the locus-locus interactions of VDR and CYP2R1 revealed two models that involved combined SNPs of VDR and CYP2R1 were statistically significant (P<0.05). Our data suggest that age and gender may have an impact on the association of three SNPs (rs2228570, rs731236, and rs2060793) in genes of the vitamin D pathway with the risk of mite-sensitized PER in this Chinese population. The VDR and CYP2R1 variants may be involved in genetic interactions in the pathogenesis of PER.

Association study on ADAM33 polymorphisms in mite-sensitized persistent allergic rhinitis in a Chinese population.

BACKGROUND: The ADAM33 gene has been identified as a potentially important asthma candidate gene and polymorphisms in this gene have been shown to be associated with asthma and seasonal allergic rhinitis. OBJECTIVE: To assess whether the ADAM33 polymorphisms are associated with persistent allergic rhinitis (PER) due to house dust mites in a Chinese population. METHODS: In a hospital-based case-control study of 515 patients with mite-sensitized PER and 495 healthy controls, we genotyped seven single nucleotide polymorphisms (SNPs) in ADAM33. Serum levels of eosinophil cationic protein, total IgE and allergen-specific IgE against Dermatophagoides pteronyssinus and Dermatophagoides farinae were measured by the ImmunoCAP assays. RESULTS: In the single-locus analysis, three polymorphisms, rs3918392 (F1), rs528557 (S2) and rs2787093, were significantly associated with mite-sensitized PER. SNP S2 was associated with significantly increased risk both of asthmatic and nonasthmatic mite-sensitized PER. In the combined genotypes analysis, individuals with 2-4 risk alleles had a significantly higher risk of mite-sensitized PER (adjusted OR = 1.99, 95% CI = 1.50-2.62) than those with 0-1 risk alleles. Haplotype-based association analysis revealed that the ACAGCCT haplotype might have potential to protect against mite-sensitized PER (adjusted OR = 0.67; 95% CI = 0.49-0.90). CONCLUSIONS: Polymorphisms in the ADAM33 gene may contribute to susceptibility of mite-sensitized PER in this Chinese population.

In vivo and in vitro studies of Th17 response to specific immunotherapy in house dust mite-induced allergic rhinitis patients.

UNLABELLED: T helper (Th)17 cells have been implicated in the development of allergic rhinitis (AR), but their response to specific immunotherapy (SIT) remains unclear. We investigated the impact of SIT on Th17 response and Th1/Th2 changes in AR patients. Blood samples from AR patients (n = 20) who were monosensitized to house dust mite (HDM) were collected before the initiation of SIT (SIT-untreated) and after the end of 2-year SIT (SIT-treated) treatment. Twenty healthy volunteers were recruited as controls. In vitro HDM stimulation in peripheral blood mononuclear cells (PBMCs) was also performed. Expression levels of Th17 associated genes were determined in both PBMCs and plasma by PCR and ELISA, while Th17/Th1/Th2/IL10 producing cell proportions were evaluated in PBMCs by flow cytometry. The SIT effect was evaluated by assessing clinical symptoms. mRNA levels of Th17 specific genes (IL17 and RORC) were increased in SIT-untreated AR versus controls, and decreased following SIT treatment. SIT can change the production of Th17 associated genes (reduction of IL17, IL6, and IL23, but increase of IL27) in plasma from AR patients. Th2/Th1 ratio and proportions of Th17 cells were suppressed while IL10 producing CD4+ T cells were elevated after SIT. In vitro HDM challenge presents concordant patterns with in vivo findings: 1) increase of Th2 and Th17 response in AR patients; 2) suppression of IL10 producing CD4+ T cells in SIT-untreated AR but elevation in SIT-treated AR patients. Most importantly, a positive correlation between IL17 mRNA/protein levels and clinical symptom scores was observed. SIT significantly inhibits Th17 mediated inflammation in AR and IL17 may be a useful biomarker for both AR severity and SIT therapeutic effect. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000445774.