Multimorbidities in Allergic Rhinitis-Current Evidence from Epidemiological Studies, Treatment Trials, and Molecular Data

Genetic polymorphisms of BACH2, a key gene regulating Th2 immune response, increasing risk of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is an allergic disease characterized by the dominant differentiation of T helper cell 2 (Th2). BACH2 plays a key role in regulating Th2 immune response. This study aimed to explore the association between BACH2 single nucleotide polymorphism (SNPs) and susceptibility to AR.

METHODS

Han population from northern Shaanxi, China was chosen as subjects. After the DNA extraction from the peripheral blood of subjects, genotyping was completed through the Agena MassARRAY platform. Logistic regression analysis was used to assess the association. Multivariate dimensionality reduction (MDR) was used to evaluate the effect of the interaction between 'SNP-SNP' on susceptibility to AR. Using false-positive report probability (FPRP) analysis to test whether the significant results obtained in this study were noteworthy.

RESULTS

BACH2-rs905670 and -rs2134814 were significantly associated with increased risk of AR. The mutant allele 'A' of rs905670 (OR = 1.36, p = 0.018) and mutant allele 'G' of rs2134814 (OR = 1.34, p = 0.027) were risk genetic factors for AR. The above genetic association was further observed in the stratified analysis: BACH2-rs905670 and-rs2134814 were significantly associated with an increased risk of AR in females, aging older than 43 years, and participants working and living in the loess hills (OR > 1, p < 0.05).

CONCLUSION

BACH2-rs905670 and -rs2134814 are significantly associated with increasing AR risk.

Allergic Rhinitis: A Review

Importance

Allergic rhinitis affects an estimated 15% of the US population (approximately 50 million individuals) and is associated with the presence of asthma, eczema, chronic or recurrent sinusitis, cough, and both tension and migraine headaches.

Observations

Allergic rhinitis occurs when disruption of the epithelial barrier allows allergens to penetrate the mucosal epithelium of nasal passages, inducing a T-helper type 2 inflammatory response and production of allergen-specific IgE. Allergic rhinitis typically presents with symptoms of nasal congestion, rhinorrhea, postnasal drainage, sneezing, and itching of the eyes, nose, and throat. In an international study, the most common symptoms of allergic rhinitis were rhinorrhea (90.38%) and nasal congestion (94.23%). Patients with nonallergic rhinitis present primarily with nasal congestion and postnasal drainage frequently associated with sinus pressure, ear plugging, muffled sounds and pain, and eustachian tube dysfunction that is less responsive to nasal corticosteroids. Patients with seasonal allergic rhinitis typically have physical examination findings of edematous and pale turbinates. Patients with perennial allergic rhinitis typically have erythematous and inflamed turbinates with serous secretions that appear similar to other forms of chronic rhinitis at physical examination. Patients with nonallergic rhinitis have negative test results for specific IgE aeroallergens. Intermittent allergic rhinitis is defined as symptoms occurring less than 4 consecutive days/week or less than 4 consecutive weeks/year. Persistent allergic rhinitis is defined as symptoms occurring more often than 4 consecutive days/week and for more than 4 consecutive weeks/year. Patients with allergic rhinitis should avoid inciting allergens. In addition, first-line treatment for mild intermittent or mild persistent allergic rhinitis may include a second-generation H1 antihistamine (eg, cetirizine, fexofenadine, desloratadine, loratadine) or an intranasal antihistamine (eg, azelastine, olopatadine), whereas patients with persistent moderate to severe allergic rhinitis should be treated initially with an intranasal corticosteroid (eg, fluticasone, triamcinolone, budesonide, mometasone) either alone or in combination with an intranasal antihistamine. In contrast, first-line therapy for patients with nonallergic rhinitis consists of an intranasal antihistamine as monotherapy or in combination with an intranasal corticosteroid.

Conclusions and Relevance

Allergic rhinitis is associated with symptoms of nasal congestion, sneezing, and itching of the eyes, nose, and throat. Patients with allergic rhinitis should be instructed to avoid inciting allergens. Therapies include second-generation H1 antihistamines (eg, cetirizine, fexofenadine, desloratadine, loratadine), intranasal antihistamines (eg, azelastine, olopatadine), and intranasal corticosteroids (eg, fluticasone, triamcinolone, budesonide, mometasone) and should be selected based on the severity and frequency of symptoms and patient preference.