Nasal Nitric Oxide and Nasal Cytology as Predictive Markers of Short-Term Sublingual Allergen-Specific Immunotherapy Efficacy in Children with Allergic Rhinitis

Background Few studies have been conducted on the short-term response to sublingual immunotherapy (SLIT). Objective The purpose of our experimental trial was to evaluate if two markers such as nasal nitric oxide (nNO) and nasal cytology could be useful to identify a precocious clinical efficacy of SLIT treatment. Methods We enrolled 34 children aged 6 to 14 years old with diagnosis of allergic rhinitis (AR) and documented sensitization towards house dust mites. We started allergoid-monomeric tablets immunotherapy along with any conventional therapy for AR and we evaluated at baseline (T0), after one (T1), two (T2), three (T3), and six months (T6) the effects of the treatment through the study of: i) a visual analogue scale (VAS 1-10); ii) measurement of nNO; iii) measurement of FeNO; iv) nasal cytology; v) spirometry; and vi) evaluation of any conventional therapy. Results We observed an improvement in symptoms evaluated by global VAS (T0 vs. T6: 47.13 vs. 17.57; p < .05) and a statistically significant reduction of nNO (1035.2 ± 956.08 vs. 139.2 ± 59.01; p < .05). In this case, significance was reached when the patients completed the 6 months of treatment. Cytological evaluation revealed significant reduction in nasal eosinophils (T0 vs. T6: 87% vs. 16%; p < .01). Moreover, at T0, 56% of patients had also neutrophils that were reduced up to the 8% at T6 (p < .05). Conclusions Our data confirm the effectiveness of SLIT treatment from a clinical perspective and identifies two biomarkers, such as nNO and nasal cytology, as predictive of treatment efficacy in the short term.

Efficacy of Hypertonic Saline Irrigation for Nasal Symptoms in Children with Perennial Allergic Rhinitis: A Randomized Double-Blind Study

Background: Nasal saline irrigation was an adjunctive therapy of allergic rhinitis (AR). It has been suggested that the use of hypertonic saline (HS) is better than normal saline (NSS) in treatment of AR. Reduction of mucosal edema by hypertonicity induced water transport through nasal mucosa, nasal congestion reduction and mucociliary clearance improvement. Objective: To compare total nasal symptom score (TNSS) between 3% HS and NSS irrigation in perennial allergic rhinitis children. Materials and Methods: The present study was conducted at the Allergy Center of Bhumibol Adulyadej Hospital (BAH), Royal Thai Airforce, Bangkok, Thailand between January and March 2021. Sixty-two perennial AR children were enrolled and categorized in severity level, namely mild, moderate or severe. Subjects were randomized into two groups. Each participant was blind-randomized to nasal irrigation of either 3% HS or NSS twice-daily for 4 weeks by the same investigator. The primary outcome was TNSS improvement between both groups. Secondary outcomes were quality of life, nasal congestion severity improvement, nasal cytology change and side effects. Results: TNSS improvement of 3% HS was more than NSS group (4.03±2.36 versus 2.73±3.06, p=0.034). Nasal congestion was the only symptom that differed significantly between the two groups (1.32±1.01 in 3% HS versus 0.70±1.24 in NSS, p=0.024). Reduction of congestion severity by physical examination, nasal cytology changes and side effects were comparable. Conclusion: Nasal irrigation with 3% HS in children with perennial AR had more improvement than NSS in TNSS., especially nasal congestion. Keyword: Hypertonic saline; Nasal irrigation; Allergic rhinitis; Nasal symptom score

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 and is closely associated with asthma in the context of atopic march. The development process of AR in early childhood, however, is not well understood due to the absence of definitive diagnostic criteria. We prospectively investigated the process in regard to not only the nasal symptoms and sensitization, but also the nasal cytology, in relation to asthma in a high-risk cohort. Methods: Infants under 2 years of age with atopic dermatitis (AD) and/or food allergy (FA) without a diagnosis of asthma 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 2 of those 3 categories. Results: A total of 304 children were enrolled, and 242 subjects (80%) 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 kUA/L increased from 30.6% to 74.8%. AR-like phenotypes increased from 18.4% to 65.0%. The cumulative incidence of physician-diagnosed asthma during the 2-year follow-up was significantly higher in the subjects with an AR-like phenotype at 1 year than in those with a non-AR phenotypes. Conclusions: The prevalence of an HDM-related AR-like phenotype was markedly increased during infancy in high-risk infants with AD/FA and was associated with asthma.

The Underestimated Role of Mast Cells in the Pathogenesis of Rhinopathies

Mast cells (MCs) are involved in several biological processes, such as defense against pathogens, immunomodulation, tissue repair after injury, and angiogenesis. MCs have been shown to change from protective immune cells to potent pro-inflammatory cells, influencing the progression of many pathological conditions, including autoimmune diseases and cancers. The role of MCs in the pathogenesis of rhinopathies has often been underestimated, since previous studies have focused their attention on eosinophils and neutrophils, while MCs were considered involved exclusively in allergic rhinitis. However, recent nasal cytology findings have shown the involvement of MCs in several rhinopathies, such as NARMA, NARESMA, and CRSwNP. These recent evidences highlight the crucial role that MCs play in orchestrating the inflammation of the nasal mucosa, through complex biological mechanisms, not yet fully understood. In this context, a better understanding of these mechanisms is fundamental for practicing Precision Medicine, which requires careful population selection and stratification into subgroups based on the phenotype/endotype of the patients, in order to guarantee the patient a tailored therapy. Based on this background, further studies are needed to understand the pathophysiological mechanisms involving MCs and, consequently, to develop targeted therapies aimed to obtain a selective inhibition of tissue remodeling and preventing MC-mediated immune suppression.