The Association of IgE Levels with ADAM33 Genetic Polymorphisms among Asthmatic Patients

ADAM33's Role in Asthma Pathogenesis: An Overview

Asthma is a complex chronic respiratory disease characterized by airway hyperresponsiveness, inflammation, and obstruction. Many genes have been identified as associated with asthma but none with such substantial significance as the ADAM33 gene due to its role in airway remodeling and bronchial hyperresponsiveness. This review summarizes the current knowledge on the genetic and functional aspects of ADAM33 in asthma pathogenesis. We highlight its genetic variants associated with asthma susceptibility and severity, as well as the functional effects of ADAM33 on airway remodeling, smooth muscle cell proliferation, and its interplay with environmental factors. Additionally, we discuss the potential clinical implications of ADAM33 as a therapeutic target for asthma management.

IL18 Gene Polymorphism Is Associated with Total IgE in Adult Subjects with Asthma

The allergic asthma phenotype is characterized by a T helper type 2 (Th2) immune response, based on Immunoglobulin E (IgE)-mediated type 1 hypersensitivity reactions. Total IgE is the sum of all IgE types produced by the human body and is used as a biomarker of inflammation in asthma. We analysed data collected in 143 asthma cases (median age 42.1 years) from the general Italian population (GEIRD survey; 2008-2010) to identify single nucleotide polymorphisms (SNPs) in candidate genes that are associated with total IgE in adult subjects with asthma. These patients reported respiratory symptoms in response to perennial allergens and provided data on 166 SNPs tagging 50 candidate genes or gene regions. Replication of the statistically significant results was performed in 842 asthma cases from other European countries (ECRHS II survey; 1998-2002). SNP rs549908 in interleukin 18 (IL18) gene was significantly associated with total IgE in GEIRD, and this result was replicated in ECRHS II. SNP rs1063320 in the human leukocyte antigen G (HLA-G) gene was identified in GEIRD, but this association was not replicated in ECRHS II. Further investigating IL18 and its biological pathways could be important for developing new therapeutic targets, due to its involvement in inflammatory response processes.

In Silico Evaluation of Nonsynonymous SNPs in Human ADAM33: The Most Common Form of Genetic Association to Asthma Susceptibility

ADAM33 is a zinc-dependent metalloprotease of the ADAM family, which plays a vital biological role as an activator of Th2 cytokines and growth factors. Moreover, this protein is crucial for the normal development of the lung in the fetus two months after gestation leading to determining lung functions all over life. In this regard, mutations in ADAM33 have been linked with asthma risk factors. Consequently, identifying ADAM33 pathogenic nonsynonymous single-nucleotide polymorphisms (nsSNPs) can be very important in asthma treatment. In the present study, 1055 nsSNPs of human ADAM33 were analyzed using biocomputational software, 31 of which were found to be detrimental mutations. Precise structural and stability analysis revealed D219V, C669G, and C606S as the most destabilizing SNPs. Furthermore, MD simulations disclosed higher overall fluctuation and alteration in intramolecular interactions compared with the wild-type structure. Overall, the results suggest D219V, C669G, and C606S detrimental mutations as a starting point for further case-control studies on the ADAM33 protein as well as an essential source for future targeted mechanisms.

GSDM gene polymorphisms regulate the IgE level in asthmatic patients

Background

Gasdermin A (GSDMA) and gasdermin B (GSDMB) have been associated with childhood and adult asthma in many populations including the Jordanian population. It is also known that IgE plays a crucial role in various allergic disorders, such elevated levels of total serum IgE were detected in asthma and allergic rhinitis. IgE immunoglobulin is responsible for the release of numerous inflammatory mediators, such as histamine and prostaglandins, from mast cells in asthmatic patients.

Objective

In this study, single nucleotide polymorphisms of GSDMA (rs7212938, T/G) and GSDMB (rs7216389, T/C) in Jordanian population were investigated for their association with total IgE levels in serum of asthmatic children and adult subjects.

Methods

The genetic polymorphism analysis for SNPs was performed using the polymerase chain reaction (PCR)/restriction fragment length polymorphism method (RFLP). Three analysis models were applied to the genotype data: co-dominant, dominant and recessive.

Results

Our data demonstrate a significant correlation between GSDMB genetic SNP (rs7216389) and the total IgE serum level. Where one minor allele in the GSDMB gene is sufficient to induce significant changes in the IgE serum levels and plays a role in the pathogenesis of asthma in asthmatic children of the Jordanian population. Suggesting that this polymorphism might have a protective effect against asthma risk. While the presence of the GSDMB polymorphism alone might not be sufficient to associate with the high risk of developing asthma or responding to it in adults in Jordanian population.

Conclusion

In conclusion, the current study confirms the significant association of GSDMB genetic SNP (rs7216389) with IgE levels in asthma patients in Jordanian population, while no significant correlation of GSDMA and IgE level was found in both child and adult asthmatic patients.

Vitamin D Levels in Asymptomatic Children and Adolescents with Atopy during the COVID-19 Era

This study assessed vitamin D status in asymptomatic children and adolescents in Greece, with and without atopy, and possible changes during the coronavirus disease 2019 (COVID-19) pandemic. Serum levels of 25-hydroxy-vitamin D (25(OH)D) and total immunoglobulin E (IgE), and eosinophil count were measured in 340 asymptomatic children and adolescents (155 males, 185 females), mean age 8.6 ± 4.6 years, recruited over a period of 24 months (February 2019–January 2021). Atopy, defined by high level of IgE for age, was associated with vitamin D deficient status (p = 0.041). Subjects with and without atopy showed similar rates of insufficient and normal levels of 25(OH)D. The median level of 25(OH)D was significantly higher in subjects recruited during the pandemic, when home confinement rules were observed, than before the pandemic, and significantly more children had normal levels of 25(OH)D (p < 0.001), but no differences were noticed for IgE levels or eosinophil count. These results support a link between vitamin D and allergic and infectious inflammations, and specifically the association of vitamin D deficiency with asymptomatic atopy, defined as increased IgE level for age.