FCER2 T2206C variant associated with FENO levels in asthmatic children using inhaled corticosteroids: The PACMAN study

Single-cell RNA landscape of osteoimmune microenvironment in osteoporotic vertebral compression fracture and Kümmell's disease

Background: Single-cell RNA sequencing (scRNA-seq) enables specific analysis of cell populations at single-cell resolution; however, there is still a lack of single-cell-level studies to characterize the dynamic and complex interactions between osteoporotic vertebral compression fractures (OVCFs) and Kümmell's disease (KD) in the osteoimmune microenvironment. In this study, we used scRNA-seq analysis to investigate the osteoimmune microenvironment and cellular composition in OVCFs and KD. Methods: ScRNA-seq was used to perform analysis of fractured vertebral bone tissues from one OVCF and one KD patients, and a total of 8,741 single cells were captured for single-cell transcriptomic analysis. The cellularity of human vertebral bone tissue was further analyzed using uniform manifold approximation and projection. Pseudo-time analysis and gene enrichment analysis revealed the biological function of cell fate and its counterparts. CellphoneDB was used to identify the interactions between bone cells and immune cells in the osteoimmune microenvironment of human vertebral bone tissue and their potential functions. Results: A cellular profile of the osteoimmune microenvironment of human vertebral bone tissue was established, including mesenchymal stem cells (MSCs), pericytes, myofibroblasts, fibroblasts, chondrocytes, endothelial cells (ECs), granulocytes, monocytes, T cells, B cells, plasma cells, mast cells, and early erythrocytes. MSCs play an immunoregulatory function and mediate osteogenic differentiation and cell proliferation. The differentiation trajectory of osteoclasts in human vertebral bone tissue was also revealed. In addition, ECs actively participate in inflammatory infiltration and coupling with bone cells. T and B cells actively participate in regulating bone homeostasis. Finally, by identifying the interaction of ligand-receptor pairs, we found that immune cells and osteoclasts have bidirectional regulatory characteristics, have the effects of regulating bone resorption by osteoclasts and promoting bone formation, and are essential for bone homeostasis. It is also highlighted that CD8-TEM cells and osteoclasts might crosstalk via CD160-TNFRSF14 ligand-receptor interaction. Conclusion: Our analysis reveals a differential landscape of molecular pathways, population composition, and cell-cell interactions during OVCF development into KD. OVCFs exhibit a higher osteogenic differentiation capacity, owing to abundant immune cells. Conversely, KD results in greater bone resorption than bone formation due to depletion of MSCs and a relatively suppressed immune system, and this immune imbalance eventually leads to vertebral avascular necrosis. The site of action between immune cells and osteoclasts is expected to be a new therapeutic target, and these results may accelerate mechanistic and functional studies of osteoimmune cell types and specific gene action in vertebral avascular necrosis and pathological bone loss diseases, paving the way for drug discovery.

[The correlation between FCER2 gene polymorphism and the efficacy of inhaled corticosteroids in patients with chronic rhinosinusitis]

Objective:To investigate the correlation between FCER2（2206A>G） gene polymorphism and the efficacy of inhaled corticosteroids（ICS） in patients with chronic rhinosinusitis（CRS）. Methods:A total of 208 CRS patients were routinely treated with functional endonasal sinus surgery and postoperative ICS. DNA extraction, PCR amplification and gene sequencing were performed to observe the FCER2（2206A>G） gene polymorphism and calculate the allele frequency. The visual analog scale（VAS） score, Lund-Kennedy score, and computed tomography（CT） Lund-Mackay score were determined 6 months after surgery among patients with different genotypes. Moreover, the polymorphism frequency was compared among different subgroups（chronic rhinosinusitis with nasal polyps versus chronic rhinosinusitis without nasal polyps, eosinophilic chronic rhinosinusitis versus non-eosinophilic chronic rhinosinusitis）. Results:There were FCER2（2206A>G） gene polymorphism in patients with CRS, and the phenotypes included 3 genotypes, AA, AG and GG, with distribution frequencies of 68（32.7%）, 116（55.8%） and 24（11.5%） cases, respectively. No significant differences were found in age, VAS score, nasal endoscopic Lund-Kennedy score and CT imaging Lund-Mackay score among patients with CRS of each genotype before surgery. In patients with the AA genotype, the changes in VAS score（5.74±1.10）, Lund Kennedy score（5.92 ± 1.14）, and CT imaging Lund-Mackay score（13.26±4.26） were significantly higher than in patients with the AG（4.37±0.86, 5.37±1.24, 10.82±3.77） and GG（4.26±0.80, 5.18±1.56, 10.10±3.53） genotype（P<0.05）. However, there were no marked difference between patients with the AG genotype and those with the GG genotype（P>0.05）. Compared with patients with non-eosinophilic sinusitis, Among them, the differences between the GG genotype and AG /AA genes were more significant in eosinophilic sinusitis compared to non-eosinophilic sinusitis（P<0.01）. Conclusion:The FCER2（2206A>G） gene in patients with CRS has genetic polymorphism and is associated with the recovery of CRS patients after surgery, individual corticosteroid sensitivity, and subgroup variability.

SNPs inFAM13AandIL2RBgenes are associated with FeNO in adult subjects with asthma

Nitric oxide has different roles in asthma as both an endogenous modulator of airway function and a pro-inflammatory mediator. Fractional exhaled nitric oxide (FeNO) is a reliable, quantitative, non-invasive, simple, and safe biomarker for assessing airways inflammation in asthma. Previous genome-wide and genetic association studies have shown that different genes and single nucleotide polymorphisms (SNPs) are linked to FeNO. We aimed at identifying SNPs in candidate genes or gene regions that are associated with FeNO in asthma. We evaluated 264 asthma cases (median age 42.8 years, female 47.7%) who had been identified in the general adult population within the Gene Environment Interactions in Respiratory Diseases survey in Verona (Italy; 2008-2010). Two hundred and twenty-one tag-SNPs, which are representative of 50 candidate genes, were genotyped by a custom GoldenGate Genotyping Assay. A two-step association analysis was performed without assuming ana priorigenetic model: step (1) a machine learning technique [gradient boosting machine (GBM)] was used to select the 15 SNPs with the highest variable importance measure; step (2) the GBM-selected SNPs were jointly tested in a linear regression model with natural log-transformed FeNO as the normally distributed outcome and with age, sex, and the SNPs as covariates. We replicated our results within an independent sample of 296 patients from the European Community Respiratory Health Survey III. We found that SNP rs987314 in family with sequence similarity 13 member A (FAM13A) and SNP rs3218258 in interleukin 2 receptor subunit beta (IL2RB) gene regions are significantly associated with FeNO in adult subjects with asthma. These genes are involved in different mechanisms that affect smooth muscle constriction and endothelial barrier function responses (FAM13A), or in immune response processes (IL2RB). Our findings contribute to the current knowledge on FeNO in asthma by identifying two novel SNPs associated with this biomarker of airways inflammation.

Polymorphisms in the FCER2 gene have associations with asthma and chronic obstructive pulmonary disease

Background

Asthma and chronic obstructive pulmonary disease (COPD) are heterogenetic diseases and exhibit many similarities. Dutch hypothesis proposed that these two diseases may have common genetic origins. This study aims to investigate whether asthma and COPD share a common genetic background in Chinese patients.

Methods

In this case-control study, single nucleotide polymorphisms (SNPs) were genotyped using SNaPshot. Haplotype disease analysis and haplotype phenotype analysis were applied to assess the relationship between three polymorphisms of the FCER2 gene and the risk of COPD/asthma. Additionally, associations between polymorphisms of the FCER2 gene and phenotypes were analyzed.

Results

We detected ten SNPs of seven genes (FCER1A, FCGR2A, FCGR2B, CHI3L1, ADRB2, STAT6, and FCER2) expressed by airway epithelial cells. We detected genotypes and allele distributions in 251 COPD patients, 597 asthma patients, and 632 healthy controls. A significant difference was found in the FCER2 gene (rs28364072) between COPD patients and controls (P=0.009). Significant differences were observed in the genotype and allele distributions of rs1801274 (FCGR2A), rs12368672 (STAT6), and rs2228137 (FCER2) between asthma patients and controls (P=0.004, 0.007 and 0.010, respectively). Notably, polymorphisms of FCER2 gene were associated with the risk of both COPD (P=0.009 for rs28364072) and asthma (P=0.01 for rs2228137). Haplotype analysis revealed that haplotype T-G-T (alleles of rs28364072, rs2228137, and rs3760687, respectively) was significantly associated with a higher risk of asthma [odds ratios (OR) =2.25, 95% confidence interval (CI): 1.26-4.01, P=0.006]. Further analysis showed that the C-A-C haplotype and C-G-T haplotype were associated with increased blood eosinophils in either COPD or asthma patients (P=0.034, and P<0.001, respectively). Moreover, haplotypes C-A-C, C-G-C, and T-G-C showed significant associations with serum IgE levels in asthma patients (P=0.002, 0.041, and 0.004, respectively).

Conclusions

Our data suggest that the FCER2 gene might associate with predisposition to asthma and COPD, while FCER2 haplotypes were associated with pulmonary function measurements and blood eosinophils counts in both diseases. Our findings support the common genetic basis for asthma and COPD, suggesting a potential therapeutic target for the two diseases.

Associations between Second-Hand Tobacco Smoke Exposure and Cardiorespiratory Fitness, Physical Activity, and Respiratory Health in Children

BACKGROUND

Cardiorespiratory fitness (CRF) and physical activity (PA) are associated with a plethora of positive health effects. Many UK children fail to meet the recommended level of PA, with an observed decline in CRF levels over recent decades. Second-hand tobacco smoke (SHS) is responsible for a significant proportion of the worldwide burden of disease, but little is understood regarding the impact of SHS exposure on CRF and PA in children. The aim of this study was to test the associations between SHS exposure and CRF, PA, and respiratory health in children.

METHOD

Children (9-11 years) from UK primary schools in deprived areas participated (n = 104, 38 smoking households). Surveys determined household smoking, and exhaled carbon monoxide was used to indicate children's recent SHS exposure. CRF (VO_2peak) was assessed via maximal treadmill protocol using breath-by-breath analysis. Fractional exhaled nitric oxide and spirometry were utilised as indicators of respiratory health.

RESULTS

Linear regression models demonstrated that SHS exposure was negatively associated with allometrically scaled VO_2peak (B = -3.8, p = 0.030) but not PA or respiratory health.

CONCLUSION

The results indicate that SHS is detrimental to children's CRF; given that approximately one-third of children are regularly exposed to SHS, this important finding has implications for both public health and the sport and exercise sciences.

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

Correlations between exhaled nitric oxide, rs28364072 polymorphism of FCER2 gene, asthma control, and inhaled corticosteroid responsiveness in children with asthma

In children with asthma, the responsiveness of inhaled corticosteroids (ICS) is depended on asthma endotype and phenotype. This study aimed to describe the clinical and biological characteristics, and its correlation with polymorphism of rs28364072 in FCER2 of asthmatic children. This work aimed to study the correlation between fractional concentration of exhaled nitric oxide (FE_NO) level and rs28364072 polymorphism of FCER2 gene with ICS responsiveness and disease control in children with asthma. This study was a prospective and descriptive study. All clinical characteristics, FE_NO, blood eosinophil counts (BEC), skin prick test (SPT), total IgE, asthma control test, and FCER2 gene polymorphism were performed for each patient. One hundred and seven asthmatic children who were over 5 years old (9.2 ± 2.6), were included. Patients with FE_NO > 20 ppb had higher percentage of positive SPT, total IgE level, and BEC (89.2 vs 80.0%, 851.1 vs 656.9 UI ml^-1, and 785 ± 576 G L^-1 vs 425 ± 364 G L^-1; respectively). Among them, there were 54.2% of homozygous TT, 36.4% of heterozygous TC, and 9.4% of homozygous CC of rs28364072 polymorphism in FCER2. The percentage of patients with controlled asthma was increasing after 1 month and 3 months (47.1% and 58.8%; respectively). During the study, the ICS was decreasing as indicated by asthma control (348 ± 118 mcg at 1st month vs 329 ± 119 mcg at 3rd month; p < 0.05). CC genotype had the lowest level of increasing FEV1 compared to that in genotype TC and TT (8.4% vs 8.7% and 27.1%; p > 0.05 and p < 0.05; respectively). The percentage of polymorphism in rs28364072 of FCER2 was significant higher in patients with controlled asthma compared to uncontrolled asthma. Asthmatic children with high FE_NO and rs28364072 polymorphism in FCER2 gene are good responders to ICS; however, asthmatic children with homozygous variant CC of rs28364072 are poorly responsive to ICS.

Pharmacogenetics of Pediatric Asthma: Current Perspectives

Asthma is a chronic respiratory disease that affects 339 million people worldwide and has a considerable impact on the pediatric population. Asthma symptoms can be controlled by pharmacological treatment. However, some patients do not respond to therapy and continue suffering from symptoms, which impair the quality of life of patients and limit their daily activity. Genetic variation has been shown to have a role in treatment response. The aim of this review is to update the main findings described in pharmacogenetic studies of pediatric asthma published from January 1, 2018 to December 31, 2019. During this period, the response to short-acting beta-agonists and inhaled corticosteroids in childhood asthma has been evaluated by eleven candidate-gene studies, one meta-analysis of a candidate gene, and six pharmacogenomic studies. The findings have allowed validating the association of genes previously related to asthma treatment response (ADRB2, GSDMB, FCER2, VEGFA, SPAT2SL, ASB3, and COL2A1), and identifying novel associations (PRKG1, DNAH5, IL1RL1, CRISPLD2, MMP9, APOBEC3B-APOBEC3C, EDDM3B, and BBS9). However, some results are not consistent across studies, highlighting the need to conduct larger studies in diverse populations with more homogeneous definitions of treatment response. Once stronger evidence was established, genetic variants will have the potential to be applied in clinical practice as biomarkers of treatment response enhancing asthma management and improving the quality of life of asthma patients.

FCER2 T2206C variant associated with FENO levels in asthmatic children using inhaled corticosteroids: The PACMAN study

BACKGROUND

The FCER2 gene, via encoding of the CD23 receptor, plays an important role in the regulation of IgE responses. A genetic variant of the FCER2 gene (T2206C) was previously shown to be associated with IgE levels in asthmatic children. IgE sensitization has also been linked to increased levels of fractional exhaled nitric oxide (FENO).

OBJECTIVE

To investigate whether the FCER2 T2206C variant influences FENO levels in asthmatic children with a reported use of inhaled corticosteroids (ICS).

METHODS

This cross-sectional study involved 593 asthmatic children with a reported use of ICS, availability of FENO measurements and genotyping data on the FCER2 T2206C variant (rs28364072). An additive genetic model was assumed, and the association between the FCER2 T2206C variant and the log-transformed (ln) FENO levels was evaluated using linear regression analysis, adjusted for age, sex, adapted British Thoracic Society (BTS) treatment steps and atopy.

RESULTS

The mean age of the population was 9.1 ± 2.2 years, and the median of FENO levels was 13.0 ppb with an interquartile range (IQR) of (8.0-27.5 ppb). The minor allele (G) frequency of rs28364072 was 29.6%, and each extra copy of the G allele was significantly associated with a lower level of the geometric mean of FENO (log scale, β = -0.12, 95% CI: -0.23, -0.02).

CONCLUSION AND CLINICAL RELEVANCE

Our results showed that the FCER2 T2206C variant was significantly associated with lower FENO levels in carriers of the G allele. Nevertheless, this SNP contributed little to the variability in FENO levels in this patient population. Our findings contribute to the present knowledge on FENO in asthmatic children; however, future replication studies are required to establish the role of this gene in relation to FENO.