Effect of inhaled allergens and air pollutants on childhood rhinitis development

In ovo very early-in-life exposure to diesel exhaust induced cardiopulmonary toxicity in a hatchling chick model

Diesel exhaust (DE) had been associated with cardiopulmonary toxicity and developmental toxicity. However, neonatal very early-in-life exposure had not been extensively studied previously. To investigate the potential effects of neonatal very early-in-life exposure to DE, a brand-new chicken embryo in ovo exposure model had been established, with which the cardiopulmonary effects of DE exposure via air cell infusion at embryonic day 18/19 (ED18/19) were assessed in hatchling chicks post-hatch 0-, 1-, or 2-weeks. Heart rates were assessed with electrocardiography. Cardiac and pulmonary morphologies were investigated with histopathological methods. Cardiopulmonary effects were explored with immunohistochemistry for alpha smooth muscle actin (alpha-SMA). In further investigations, the expression levels of phosphorylated AhR, serum levels of TGF-β1, phosphorylated SMAD2/3 and phosphorylated p38MAPK were assessed in the lung tissues. Significantly elevated heart rates, increased right ventricular wall thickness and cardiac collagen deposition were observed in the hearts of exposed hatchling chicks. Significantly increased collagen deposition as well as increased vascular alpha-SMA layer thickness/decreased cavity area were observed in exposed animal lungs. These effects persisted up to two weeks post-hatch. Mechanistic studies revealed elevated phosphorylated AhR expression levels in 0-week and 1-week chicken lungs, while phosphorylated SMAD2/3 levels significantly increased in 0-week chicken lungs but decreased in 2-week chicken lungs following DE exposure. Phosphorylation of p38MAPK did not remarkably increase until 2-week post-hatch. In summary, the novel chicken neonatal very early-in-life exposure model effectively exposed the chicken embryos during the neonatal initial breathing, resulting in cardiopulmonary toxicity, which is associated with AHR, TGF-β1 and MAPK signaling.

Current and emerging pharmacotherapy for pediatric allergic rhinitis

INTRODUCTION

Allergic rhinitis (AR) is a global health problem in adults as well as the younger population, continuously increasing and posing a significant problem for patients, health care systems and economies. For the younger population, some aspects differ from treatment of adults, namely, prevention, compliance and adherence.

AREAS COVERED

This narrative review summarizes all the pharmacotherapeutic options with special focus on the pediatric population. Moreover, it elucidates prevention strategies as well as future developments of AR treatment. Currently, symptomatic therapy in the form of steroids and antihistamines is applied topically and systemically where steroids need to be administered with caution and for a very short term. The only disease-modifying and causal treatment is allergen immunotherapy administered sublingually and subcutaneously. Future and current novel therapeutic options are human monoclonal antibodies.

EXPERT OPINION

The greatest potential for future developments currently lie in allergen immunotherapy and here in different routes of administration and modification of (recombinant) allergens as well as immune-modulating adjuvants and nanoparticles. Secondly, monoclonal antibodies are promising molecules blocking and/or interfering with up- and downstream immune mechanisms. Another important aspect lies in prevention of allergic sensitization and disease progression through both AIT and biologics which is particularly true for the pediatric population.