The CTLA-4 +49 A/G and -318 C/T polymorphisms and susceptibility to asthma: a meta-analysis

Genetic association study of CTLA4 and FCεRIα polymorphisms in asthmatic patients in the southwestern region of Iran

Asthma is a heterogeneous chronic pulmonary disease that develops due to the interaction of genetic and environmental factors. This study aimed to investigate the polymorphisms of CTLA4(SNP-318C > T, SNP + 49A > G) and FCεRIα(SNP-344T > C) genes in asthmatic patients in Southwest Iran. The study enrolled 200 patients with asthma of Arab and Bakhtiary descent and 200 healthy controls, where asthmatic patients and healthy controls were selected based on a spirometry test. Genomic DNA from whole blood samples using the TaqMan assay was used to study the genotypes of patients and healthy controls.The results indicated no statistically significant difference between cases and controls for the SNP-344C > T of the FCεR1α gene and the SNP + 49A > G, SNP-318C > T of the CTLA4 gene. There was a significant correlation between the CTLA4-318C > T allele frequency in both the case and control groups (OR = 1.83; 95%CI, 1.14-2.94; P = 0.01). We stratified genotypes according to age, gender, ethnicity, and smoking status and discovered a significant suggestive association between the SNP + 49A > G of the CTLA4 gene and smoking. Additionally, SNP + 49A > G was found to be associated with gender and age. The results indicated that the SNP-318C > T polymorphism in the CTLA4 gene might contribute to the development of asthma in the studied population. Meanwhile, smoking can exacerbate asthma in individuals with SNP + 49A > G of the CTLA4 gene.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1964525 .

Asthma susceptible genes in children: A meta-analysis

BACKGROUND

During the last decade, a number of studies have evaluated the potential association between some genetic polymorphisms and childhood asthma risk, however, the results of published studies appear conflicts. The aim of the present study was to investigate association between genetic polymorphisms and pediatric asthma.

METHODS

Relevant studies were searched in PubMed, Embase, Web of Science, CNKI (China National Knowledge Infrastructure), Wanfang, and Weipu database. Pooled odds ratios (OR) with 95% confidence interval (CI) were calculated to evaluate the strength of the associations.

RESULTS

Fifty five case-control studies were finally included in this meta-analysis, including 17,971 pediatric asthma cases and 17,500 controls. Eighteen polymorphisms were identified, of which, 9 polymorphisms were found to be associated with asthma risk in overall populations: IL-13 +2044G/A, IL-4 -590C/T, ADAM33 F+1, ADAM33 T2, ADAM33 T1, ADAM33 ST+4,ORMDL3 rs7216389, VDR FokI, VDR TaqI. Furthermore, IL-13 +2044G/A, IL-4 -590C/T, ADAM33 T2, ADAM33 T1, VDR BsmI polymorphisms may cause an increased risk of asthma among Chinese children.

CONCLUSIONS

This meta-analysis found that IL-13 +2044G/A, IL-4 -590C/T, ADAM33 F+1, ADAM33 T2, ADAM33 T1, ADAM33 ST+4,ORMDL3 rs7216389, VDR FokI, and VDR TaqI polymorphisms might be risk factors for childhood asthma. Further study with large population and more ethnicities is needed to estimate these associations.

A meta-analysis of the association between CTLA-4 genetic polymorphism and susceptibility of asthma

BACKGROUND

Numerous studies have reported an association between cytotoxic T-lymphocyte associated antigen 4 gene (CTLA4) polymorphism and susceptibility to asthma, in different populations, but the results have been inconsistent. We performed a meta-analysis of 19 published case-control studies to obtain a reasonably accurate estimation of the relationship between CTLA4 polymorphism and asthma.

METHODS

We searched the Pubmed, EMBASE, Chinese National Knowledge Infrastructure, and Wanfang databases and extracted data from 19 independent, eligible studies. Odds ratios (ORs) with 95% confidence intervals (CIs) and Egger test were separately used to assess the strength of associations and publication bias.

RESULTS

A total of 19 case-control studies involving 4831 cases and 4534 controls were identified. The combined results revealed that there was significant association between the +49A/G polymorphism and asthma (for GG + GA vs. AA: OR = 0.82, 95% CI = 0.70-0.97, P = .02). Stratification by race or age indicated a significant association between the CTLA-4 +49 GA+GG genotype and asthma in Asians (OR = 0.80, 95% CI = 0.68-0.95, P = .01) and children (OR = 0.75, 95% CI = 0.62-0.90, P = .002), but there was no association in whites (OR = 0.94, 95% CI = 0.80-1.10, P = .44) and adults (OR = 0.85, 95% CI = 0.68-1.06, P = .15). Additionally, there was a significant association with atopic asthma under the random-effects model (OR = 0.81, 95% CI = 0.67-0.98, P = .03). In addition, there was no significant association between the -318 C/T polymorphism and asthma risk.

CONCLUSIONS

Our meta-analysis results suggested that the +49A/G polymorphism in CTLA-4 was an important risk factor for asthma susceptibility, especially in Asian individuals, children, and atopic patients.

Association of Single Nucleotide Polymorphisms in Toll-like Receptor Genes With Asthma Risk: A Systematic Review and Meta-analysis

Purpose

Asthma is a complex disease, with contributions from multiple genes, various genetic backgrounds, and environmental factors. Many human epidemiological studies have demonstrated that single nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) genes are inconsistently associated with asthma risk. Some have demonstrated differences concerning the study design and effect size, and conflicting results have been reported. A meta-analysis is necessary to determine the magnitude of this association.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic search and meta-analysis of the literature was conducted to estimate the association of SNPs in TLR genes with asthma risk. We screened the medical literature based on the following keyword searches in MEDLINE and EMBASE databases: 'TLR', 'polymorphism', 'asthma', and their combinations.

Results

Meta-analysis of eight studies on TLR4 Asp299Gly showed a marginal association of TLR4 with asthma risk (odds ratio [OR]=0.814 [95% confidence interval [CI], 0.652-1.016; P=0.069]) in the recessive model. TLR4 Thr399Ile was not associated with asthma risk under any genetic model. Meta-analysis of four studies on TLR2 Arg753Gln indicated that TLR2 might be significantly associated with asthma in the dominant and codominant models (P=0.029, P=0.030, and P=0.009, respectively). TLR9 -1237 was marginally associated with asthma risk (OR=0.408 [95% CI, 0.163-1.021; P=0.065]) in the codominant model. Analysis using the allele contrast model showed that the major TLR9 -1237 T allele tended to be a significant protective factor with OR=0.689 (95% CI, 0.471-1.007; P=0.055).

Conclusions

The results showed that TLR4 Asp299Gly, TLR2 Arg753Gln, and TLR9-1237 might contribute significantly to asthma susceptibility. Future genetic association studies would consolidate these findings.

Molecular biomarkers in clinical development: what could we learn from the clinical trial registry?

Aim: Objective of this research is to assess whether the trend of stratified medicine widely discussed in scientific literature is translated into real clinical trials registered in ClinicalTrials.gov . Methods: By semi-automatic screening of over 150,000 trials, we filtered trials with stratified biomarker to analyze their therapeutic focus, major drivers and elucidated the impact of stratified biomarker programs on trial duration and completion. Results: >5% of trials are using molecular biomarker for stratification; duration of such trials is longer. 21% of them are done in late stages and Oncology is the major focus. Conclusion: Trials with stratified biomarker in drug development has quadrupled in last decade but represents a small part of all interventional trials reflecting multiple co-developmental challenges of therapeutic compounds and companion diagnostics.

Significant association between GSTT1 null genotype and risk of asthma during childhood in Caucasians

Asthma is a complex multifactorial disorder and its management requires a better understanding of its various pathogenesis and mechanisms. Previous studies assessing the association between glutathione S-transferase T1 (GSTT1) null genotype and asthma risk during childhood reported conflicting results. To get a more precise estimation of the association between GSTT1 null genotype and risk of asthma during childhood, we performed a meta-analysis of 16 studies with a total of 18,558 subjects. Subgroup analyses were performed by ethnicity. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 %CI) was used to assess the association. Overall, there was a significant association between GSTT1 null genotype and increased risk of children asthma (OR = 1.25, 95 % CI, 1.02-1.54; P = 0.032). Subgroup analyses showed GSTT1 null genotype was associated with increased risk of children asthma in Caucasians (OR = 1.46, 95 % CI, 1.04-2.03; P = 0.027), but not in Asians (OR = 1.03, 95 % CI, 0.55-1.94; P = 0.928) and Africans (OR = 1.33, 95 % CI, 0.92-1.91; P = 0.127). There was no evidence of publication bias in the subgroup analysis of Caucasians. In conclusion, there is a significant association between GSTT1 null genotype and risk of asthma during childhood in Caucasians. More well-designed epidemiological studies are needed to further assess this association in Asians and Africans.