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

Abstract

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 (FENO) 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, FENO, 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 FENO > 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 FENO 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.

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

“…Functionally, the marker rs3760687, a promoter SNP in the FCER2 gene, was reported to alter transcriptional activity by binding transcription factors Sp1 and Sp3, leading to the regulation of CD23 expression (38). The rs28364072, also known as the FCER2 T2206C variant, was associated with asthma severity (37,41). A previous study found that the percentage of rs28364072 of FCER2 was significantly higher in patients with controlled asthma than those in patients with uncontrolled asthma (40).…”

Study of Nasal Fractional Exhaled Nitric Oxide (FENO) in Children with Allergic Rhinitis

“…This method is highly sensitive, and exhaled NO can be detected at levels as low as parts per trillion. A new NO analysis method based on the electroluminescence technique has been developed and used in clinical practice (Figure 3) [3,18]. This technique has been shown to have high accuracy and good correlation with other methods, and has the advantage of being small compared with fixed routine chemiluminescence analyzers.…”

The Genetic Factors of the Airway Epithelium Associated with the Pathology of Asthma

“…TBX21 encoding for the transcription factor T-bet, which influences naïve T lymphocytes development, was found to have a nonsynonymous variation coding for replacement of histidine 33 with glutamine (H33Q C>G) which is associated with significant improvement in bronchial hyperresponsiveness and asthma control with ICS treatment [ 86 , 87 ]. Both heterozygous and homozygous variants in the FCER2 gene are associated with increased FEV1 in response to treatment with ICS and are indicators of good responders to ICS [ 88 ]. Polymorphisms in both vascular endothelial growth factor (VEGFA) and collagen type II alpha 1 chain (COL2A1), a fibrillar collagen found in cartilage, are significantly associated with improved FEV1 response to ICS and [ 89 ].…”