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

Experimental observation of the effect of immunotherapy on CD4+ T cells and Th1/Th2 cytokines in mice with allergic rhinitis

The present study aims to investigate the effect of immunotherapy in a mouse model of allergic rhinitis (AR) and to explore the possible molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with house dust mite (HDM) extract. The mice were injected subcutaneously with HDM for immunotherapy. AR nasal symptoms were evaluated according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The nasal mucosa and lung tissue architecture and inflammatory status by histological analysis; the infiltration of eosinophils in nasal lavage fluid (NALF) of mice was observed by Diff-Quik stain; ELISA-based quantification of serum HDM-specific IgE and TH1/TH2 cytokine concentration; and flow cytometry detected the number of serum CD4+/CD8+ cells to evaluate the mechanism of immunotherapy. It was found that after immunotherapy, the AR symptom score was reduced, the number of eosinophils in NALF was reduced, and the infiltration of inflammatory cells and tissue damage in the nasal mucosa and lung tissue were alleviated. Immunotherapy can increase the number of CD4+ T cells in the peripheral blood, increase the ratio of CD4+/CD8+ cells, increase the expression of Th1 cytokines such as IL-2 and IFN-γ, reduce the expression of Th2 cytokines such as IL-4 and IL-5. The results showed that repeated intraperitoneal injection of crude extract of HDM for sensitization, followed by nasal drops can effectively construct a mouse model of AR, and subcutaneous injection of immunotherapy in mice can reduce allergic inflammation in model mice and improve the inflammatory infiltration of the nasal cavity in allergic rhinitis. Immunotherapy can reduce the expression of inflammatory factors in AR, improve Th1/Th2 balance, and may play a role in the treatment of AR by improving the function of immune cells.

Development of allergic rhinitis in early life: A prospective cohort study in high-risk infants

BACKGROUND

Allergic rhinitis (AR) is the most common allergic disease in children. The development process of AR in early childhood, however, is not well understood. We prospectively investigated the process in regard to not only the nasal symptoms and sensitization but also the nasal cytology, in relation to recurrent wheeze in a high-risk cohort.

METHODS

Infants under 2 years of age with atopic dermatitis (AD) and/or food allergy (FA) symptoms were recruited and followed prospectively for 2 years. The phenotype of perennial AR was classified based on the presence/absence of (1) persistent nasal symptoms, (2) nasal eosinophils, and (3) HDM sensitization, the most common allergen for perennial AR in Japan. AR-like phenotypes were defined as positive for at least two of those three categories. High-risk recurrent wheezer was diagnosed based on the Japanese guidelines and Global Initiative for Asthma. Cox proportional hazards regression analyses for high-risk recurrent wheeze and the AR-like phenotype, adjusting for known covariate risk factors for asthma.

RESULTS

A total of 299 children were enrolled, and 237 subjects (78%) completed the 2-year observation. The prevalence of eosinophilia in nasal secretions increased from 18.5% to 69.9%, while HDM-specific IgE ≥ 0.35 kU_A /L increased from 30.6% to 74.8%. AR-like phenotypes increased from 18.4% to 65.0%. The AR-like phenotype at 2 years was associated with development of high-risk recurrent wheezer (HR 2.062; 95% CI 1.005-4.796).

CONCLUSIONS

The prevalence of an HDM-related AR-like phenotype was markedly increased during infancy in infants with AD/FA and was associated with high-risk recurrent wheezer.