Assessing the onset of allergic rhinitis by nasal cytology and immunoglobulin E antibody levels in children

Allergic Rhinitis in Preschoolers: A Systematic Review of Diagnostics

BACKGROUND

Most studies that seek to analyze the prevalence of allergic rhinitis do not include preschool children and the diagnosis in this age group is difficult.

OBJECTIVE

Identify complementary tests to the diagnosis of allergic rhinitis in preschool children and verify if there is scientific robustness to propose a diagnostic algorithm for this condition in this age group.

METHODS

Systematic review of the literature in four databases: SCIELO, PubMed/MEDLINE, LILACS and SCOPUS. Each article was initially chosen by title, abstract and by the keywords "allergic rhinitis," "diagnosis" and "preschool." Those articles selected entered the complete reading and data extraction phase. The study was registered in the International Prospective Register of Systematic Reviews under number CRD42020207053.

RESULTS

Fourteen articles were suitable for analysis. In the assessment using Quality Assessment of Diagnostic Accuracy Studies - 2, all studies had at least one domain considered "high risk" or "undetermined risk." Seven reports of nasal cytology, seven of specific IgE, four of immediate hypersensitivity skin test, one of nasal nitric oxide, three of total IgE and one of urinary leukotriene E4 were found. Eight articles evaluated more than one diagnostic test.

CONCLUSION

There are no defined criteria for the diagnosis of allergic rhinitis in preschool children. Nasal cytology, serum specific IgE and immediate hypersensitivity skin test were the most used tests. A reliable diagnostic criterion in this age group is necessary so that in the future it is possible to propose a diagnostic algorithm for allergic rhinitis in preschool children.

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.

Endotyping allergic rhinitis in children: A machine learning approach

INTRODUCTION

The diversity of allergic rhinitis (AR) phenotypes is particularly evident in childhood, suggesting the need to analyze and identify new approaches to capture such clinical heterogeneity. Nasal cytology (NC) is a very useful diagnostic tool for identifying and quantifying nasal inflammation. Data-driven approaches such as latent class analysis (LCA) assign subjects to classes based on their characteristics. We hypothesized that LCA based on NC, including the assessment of neutrophils, eosinophils, and mast cells, may be helpful for identifying AR endotypes in children.

METHODS

A total of 168 children were enrolled. Sociodemographic characteristics and detailed medical history were obtained from their parents. All children performed NC and skin prick tests. LCA was applied for identifying AR endotypes based on NC, using the R package poLCA. All the statistical analyses were performed using R 4.0.5 software. Statistical significance was set at p ≤ .05.

RESULTS

LCA identified two classes: Class 1 (n = 126, 75%): higher frequency of children with moderate/large number of neutrophils (31.45%); almost all the children in this class had no mast cells (91.27%) and Class 2 (n = 42, 25%): higher frequency of children with moderate/large number of eosinophils (45.24%) and moderate/large number of mast cells (50%).

CONCLUSIONS

The present study used a machine learning approach for endotyping childhood AR, which may contribute to improve the diagnostic accuracy and to deliver personalized health care in the context of precision medicine.

Allergen-specific subcutaneous immunotherapy for Japanese cedar pollinosis decreases the number of metachromatic cells and eosinophils in nasal swabs during the preseason and in season

Background and objective

Nasal symptoms of allergic rhinitis can be reduced with allergen‐specific subcutaneous immunotherapy (SCIT). However, the mechanisms underlying the effectiveness of SCIT for Japanese cedar pollinosis are not well understood. We studied changes in the numbers of metachromatic cells, eosinophils and neutrophils in nasal swabs following SCIT for Japanese cedar pollinosis.

Methods

Subjects were either untreated or given SCIT for 0.5 to 13 years duration. For the 2019 seasons, nasal swabs were taken in the pollinosis preseason (immunotherapy n = 36; untreated control, n = 62) and in the pollinosis season (immunotherapy n = 45; untreated control n = 46) and the numbers of mast cells, eosinophils and neutrophils assessed by microscopy.

Results

There were significant improvements in symptom severities following SCIT in comparison to untreated subjects (P < .0003, the Mann‐Whitney U test) in preseason, and (P < .00001) in season. Metachromatic cell counts from nasal swabs of SCIT subjects in preseason and in the season were lower than those of untreated subjects (P = .0029 and P = .031, respectively). Eosinophil numbers in nasal swabs of subjects given SCIT were lower than in untreated subjects (P = .0031) in season, but not in preseason. There were no significant differences in degrees of neutrophilia between untreated and SCIT subjects in preseason and in season.

Conclusion

One mechanism underlying the effectiveness of SCIT for Japanese cedar pollinosis involves a reduction in the number of metachromatic cells in nasal swabs in the preseason and an inhibition of increases in the number of metachromatic cells and eosinophils in season.