Asthma susceptible genes in children: A meta-analysis

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.

The role of vitamin D deficiency in the development of paediatric diseases

Children's Vitamin D (VitD) fortification and supplementation are diminishing due to less outdoor exercise and insufficient VitD intake (low exogenous intake and endogenous malabsorption induced by gastrointestinal disease). Consequently, children in many developed countries suffer from VitD deficiency, which may contribute to many paediatric disorders. Our review briefly introduced the metabolic process of VitD, summarized the role of VitD in paediatric diseases such as autism, obesity, rickets and asthma. We sought to identify the link between VitD deficiency and these diseases.

Association between IL-10 (at position -592) and IL-4 (at position -589) genotype polymorphism with atopic and non-atopic asthma in children

OBJECTIVES

Asthma is the most prevalent respiratory disease, caused by chronic bronchial inflammation. Cytokines are known to play an important role in the pathophysiology of asthma. This study aimed to compare interleukin-4 (IL-4) and interleukin-10 (IL-10) gene polymorphisms between Iranian pediatric asthmatic patients and healthy controls and to investigate IL4 and IL10 gene variations in children with atopic and non-atopic asthma phenotypes.

METHODS

In this prospective case-control study, a total of 95 unrelated pediatric asthmatic patients were recruited according to the Global Initiative for Asthma (GINA) criteria. The control group comprised two subgroups of 538 and 491 healthy individuals, undergoing IL4 and IL10 polymorphism assessments, respectively. The IL4 -589C/T (rs2243250) and IL10 -592A/C (rs1800872) gene polymorphisms were evaluated using the tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) assay.

RESULTS

The findings indicated a significant difference in IL4 gene polymorphisms at position -589 between the asthmatic and healthy control groups. However, no significant difference was found in terms of IL10 gene polymorphisms, and they were not associated with atopy in the patients.

CONCLUSION

The IL4 -589C/T polymorphism (rs2243250) can be a risk factor for asthma susceptibility, whereas the IL10 -592A/C polymorphism (rs1800872) is not a risk factor in the Iranian pediatric population. The results also showed that these polymorphisms are not risk factors for atopy in asthmatic children.

Promising Immunomodulatory Effects of Bacterial Lysates in Allergic Diseases

In light of an escalating prevalence of allergic disorders, it is crucial to fully comprehend their pathophysiology and etiology. Such knowledge would play a pivotal role in the search for new therapeutic approaches concerning not only diseases’ symptoms, but also their underlying causes. The hygiene hypothesis indicates a high correlation between limited exposure to pathogens in early childhood and the risk of developing allergic disorders. Bearing in mind the significance of respiratory and digestive systems’ mucous membrane’s first-line exposure to pathogens as well as its implications on the host’s immune response, a therapy targeted at aforesaid membranes could guarantee promising and extensive treatment outcomes. Recent years yielded valuable information about bacterial lysates (BLs) known for having immunomodulatory properties. They consist of antigen mixtures obtained through lysis of bacteria which are the most common etiologic agents of respiratory tract infections. They interact with dendritic cells located in the mucous membranes of the upper respiratory tract and the gastrointestinal tract by toll-like receptors. The dendritic cells present acquired antigens resulting in innate immune response development on the release of chemokines, both stimulating monocytes and NK cells maturation and promoting polymorphonuclear neutrophil migration. Moreover, they influence the adaptive immune system by stimulating an increase of specific antibodies against administered bacterial antigens. The significance of BLs includes not only an anti-inflammatory effect on local infections but also restoration of Th1/Th2 balance, as demonstrated mainly in animal models. They decrease Th2-related cytokine levels (IL-4, IL-13) and increase Th1-related cytokine levels (IFN-γ). The reestablishment of the balance of the immune response leads to lowering atopic reactions incidence which, in addition to reduced risk of inflammation, provides the alleviation and improvement of clinical manifestations of allergic disorders. In this review, we hereby describe mechanisms of BLs action, considering their significant immunomodulatory role in innate immunity. The correlation between local, innate, and adaptive immune responses and their impact on the clinical course of allergic disorders are discussed as well. To conclude our review, we present up-to-date literature regarding the outcomes of BLs implemented in atopic dermatitis, allergic rhinitis, and asthma prevention and treatment, especially in children.

Lung function, allergic sensitization and asthma in school-aged children after viral-coinfection bronchiolitis

Our main objective was to compare the lung function, the rate of allergic sensitization and the prevalence of asthma at 7–9 years in children hospitalized for bronchiolitis with viral coinfection versus single viral infection. Observational study in children with previous bronchiolitis and current age 7–9 years. Clinical data were collected. Fraction of exhaled nitric oxide (FeNO) determination, spirometry and skin prick test for common aeroallergens were performed. A total of 181 children hospitalized for bronchiolitis (40 coinfections and 141 single infections), with median age of 8.3 years (IQR:7.5–9.1) were included. Single-HRV-infections showed lower basal FEV1(%) than coinfections (p = 0.04) and lower z-score FEV1 than single-RSV-infections (p = 0.04) or coinfections (p = 0.02). Also, single-HRV-infections had lower post-bronchodilator FEV1(%) and z-score FEV1 values than coinfections (p = 0.03 and p = 0.03). Single-HRV-bronchiolitis was an independent risk factor for FEV1 < 80% (p = 0.007). FeNO value > 25 ppb was detected in 21(12.5%) cases, without differences between viral groups (p = 0.768). The prevalence of allergic sensitization was similar in coinfections (31.4%) versus single infections (38.7%), (p = 0.428). The highest frequency of allergic rhinitis was observed in single-HRV patients (p = 0.004). The respiratory morbidity at 7–9 years of coinfected patients was similar to the single-HRV ones. In contrast, the likelihood of current asthma was up to 5 times higher in RSV/HRV coinfections than in the single-RSV-infections ones (p = 0.012). The respiratory morbidity at 7–9 years of age after severe bronchiolitis is significantly higher in single-HRV or viral coinfection patients that in single-RSV ones. Single-HRV-bronchiolitis is independently associated with lower lung function at school-age.

Meta-Analysis of Vitamin D Receptor Gene Polymorphisms in Childhood Asthma

We conducted the systematic review to investigate the potential relationship between the vitamin polymorphisms of D receptor (VDR) gene and childhood asthma. Relevant studies researching on VDR polymorphisms and asthma susceptibility were searched throughout Embase, PubMed, China Science and technology journal database (CQVIP), etc. till 12 April, 2021. We calculated the pooled odds ratios (OR) and its 95% confidence interval (CI) using RevMan 5.3 software and Stata 11.0. FokI (rs2228570) could significantly affect childhood asthma risk across co dominant model (Ff vs. FF: OR (95%CI) = 0.82 (0.65, 1.02), P = 0.071) and dominant model (ff+Ff vs. FF: OR (95%CI) = 0.77 (0.63, 0.95), P = 0.016), especially among Caucasians in additive model (f vs. F: OR (95%CI) = 0.63 (0.43, 0.92), P = 0.015) and dominant model (ff+Ff vs. FF: OR (95%CI) = 0.67 (0.51, 0.88), P = 0.004). TaqI (rs731236) was significantly related with childhood asthma in additive model (t vs. T: OR (95%CI) = 0.45 (0.23, 0.89), P = 0.022), co dominant model (Tt vs. TT: OR (95%CI) = 0.36 (0.17, 0.77), P = 0.009), and dominant model (tt+Tt vs. TT: OR (95%CI) = 0.36 (0.15, 0.87), P = 0.024) among Asian, as well as population-based subgroup in co dominant model (Tt vs. TT: OR (95%CI) = 0.53 (0.31, 0.94), P = 0.029). However, no evidence supported the role of ApaI (rs7975232) and BsmI (rs1544410) polymorphisms in childhood asthma. FokI and TaqI polymorphisms were found to be related with the susceptibility of childhood asthma. However, it seems that ApaI and BsmI polymorphisms are not related with childhood asthma susceptibility.