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Background: Thymic stromal lymphopoietin (TSLP) is recognized for its key role in promoting asthma, hence drawing considerable clinical interest as a potential therapeutic target. Population-based studies found association between single nucleotide polymorphisms (SNPs) located in the TSLP promoter region, and asthma; however, discrepancies have been also reported. Aims and Objectives: To determine whether rs1837253, rs2289276, and rs3806933 SNPs of TSLP gene are associated with asthma predisposition in a Saudi population. Materials and Methods: A total of, 272 asthmatic patients and 398 normal controls, all of Saudi citizenship, were recruited. The TSLP target DNA sequences were polymerase chain reaction (PCR) amplified using specific primers and allelic determination was performed by Sanger sequencing and capillary electrophoresis. Results: The relative frequencies for the minor allele, “T,” in all three SNPs, were smaller in asthmatics although not significant. When testing for genotypes, the homozygous T/T of all three SNPs was less frequent in asthmatic patients, but not to statistically significant levels. Both the recessive and dominant genetic models were tested. Homozygous T/T individuals for each SNP had lower odds of being asthmatics, thus suggesting a “protective” effect, although none of the SNPs in either model reached a statistical significance. Conclusion: Three SNPs in TSLP's promoter gene were not significantly associated with asthma in the Saudi population.

BACKGROUND: Acute exacerbations of bronchial asthma remain a major cause of frequent Emergency Department (ED) visits by pediatric patients. However, other factors including psychosocial, behavioural and educational, are also reportedly associated with repetitive ED visits. Therefore, it is necessary to determine whether such visits are justifiable. OBJECTIVE: The objective of this cross-sectional study was to identify risk factors associated with visits to ED by asthmatic children. METHODS: Asthmatic children (n = 297) between 1-17 years old were recruited and information collected at the time of visiting an ED facility at two major hospitals. RESULTS: Asthmatic patients visited the ED 3.9 ΁ 3.2 times-per-year, on average. Inadequately controlled asthma was perceived in 60.3% of patients. The majority of patients (56.4%) reported not receiving education about asthma. Patients reflected misconceptions about the ED department, including the belief that more effective treatments are available (40.9%), or that the ED staff is better qualified (27.8%). About half of patients (48.2%) visited the ED because of the convenience of being open 24 hours, or because they are received immediately (38.4%). Uncontrolled asthma was associated with poor education about asthma and/or medication use. Patients educated about asthma, were less likely to stop corticosteroid therapy when their symptoms get better (OR:0.55; 95% CI:0.3-0.9; P = 0.04). CONCLUSION: This study reports that most patients had poor knowledge about asthma and were using medications improperly, thus suggesting inefficient application of management action plan. Unnecessary and frequent visits to the ED for asthma care was associated with poor education about asthma and medication use. Potential deficiencies of the health system at directing patients to the proper medical facility were uncovered and underline the necessity to improve education about the disease and medication compliance of patients and their parents/guardians.

Background: The IL-4 receptor alpha subunit (IL-4Rα), when associated with the common gamma chain receptor, or the IL-13Rα1 subunit, transduces signals to STAT6 in response to IL-4 and IL-13 stimulations. This results in a number of cell-specific responses including Th2 differentiation, lymphocyte proliferation and IgE production. Given the prominent role of IL-4Rα in allergic disorders, several single-nucleotide polymorphisms (SNPs) have been found associated with asthma and other atopic disorders, including rs1805010 (I75V) and rs1801275 (Q576R) SNPs; however, lack of significant association have also been reported for some ethnic groups. The objective of this study was to determine whether IL-4Rα rs1805010 and rs1801275 polymorphisms are associated with asthma in patients from Saudi Arabia. Materials and Methods: One hundred and ninety severe asthmatic patients (11-70 years old) and 194 healthy subjects of equivalent age range were recruited for blood donation. DNA was purified and genotyping for rs1801275 and rs1805010 polymorphisms in the IL-4Rα gene was performed by PCR amplification, followed by cycle sequencing of the purified PCR fragments using BigDye chain terminator and capillary electrophoresis. Results: Pearson′s Chi-square tests showed that the minor alleles, G, for both rs1805010 and rs1801275 SNPs, were significantly more frequent in asthmatics than in the healthy group (Yates′ P < 0.05); conversely, the major alleles, A, were significantly more frequent in healthy than in asthmatics (P < 0.05). Concerning association analysis, odds for A/G-G/G genotypes were significantly higher to be associated with asthma predisposition (rs1801275: OR = 2.12; 95% CI = 1.39-3.22; P < 0.001FNx01; rs1805010: OR = 1.6; 95% CI = 1.01-2.53; P < 0.05FNx01; dominant model). Analysis of gender-genotype interactions, with genders nested within A/G-G/G, indicated higher odds for females than males of significant association with asthma (rs1801275: OR = 5.19, 95% CI = 2.09-12.94FNx01; rs1805010: OR = 3.73, 95% CI = 2.06-6.74FNx01). Rs1805010 and rs1801275 were in linkage disequilibrium (D′ = 0.27; P < 0.0004FNx01), with G-G haplotype being more frequent in asthmatics than in healthy subjects (OR = 2.43, 95% CI = 1.59-3.71FNx01). Conclusions: The risk alleles, G, of IL-4Rα rs1805010 and rs1801275 SNPs and corresponding A/G-G/G genotypes were significantly associated with asthma predisposition in asthmatics from Saudi Arabia.