Association between regulated upon activation, normal T cells expressed and secreted (RANTES) -28C/G polymorphism and asthma risk--a meta-analysis

The regulated upon activation normal T-cell expressed and secreted (RANTES) -28C/G and -403G/A polymorphisms and asthma risk: a meta-analysis

BACKGROUND AND OBJECTIVES

Genetic studies have revealed that the regulated upon activation normal T-cell expressed and secreted (RANTES) -28C/G and -403G/A polymorphisms are associated with asthma risk, but contradictory findings have also been reported. Therefore, we undertook a meta-analysis on this topic.

METHODS

The PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases were used to identify relevant studies published in the medical literature from 1990 to March 26, 2014. Nine studies (containing 2,103 cases and 2,876 controls) investigated the -28C/G polymorphism, and 11 studies (including 2,015 cases and 1,909 controls) assessed the -403G/A polymorphism.

RESULTS

The pooled results demonstrated that the -28C/G polymorphism was not associated with asthma risk in the overall populations (Caucasians, Asians, and a mixed population). However, in subgroup analysis according to age, the -28G allele was associated with an increased risk of asthma in children (odds ratio [OR] 1.27, 95 % confidence interval [CI] 1.03-1.57, P value for heterogeneity [P het] = 0.163, P value for the overall effect [P z] = 0.028). When we further stratified the studies performed in children on the basis of ethnicity, we found that the -28G allele was associated with an increased risk of asthma in Asian children (OR 1.28, 95 % CI 1.02-1.62, P het = 0.127, P z = 0.035), but not in Caucasian children (OR 1.20, 95 % CI 0.68-2.12, P het = 0.137, P z = 0.530). In subgroup analysis by asthma phenotype, no association between either atopic or non-atopic asthma and the -28C/G polymorphism was identified. For the -403G/A polymorphism, meta-analysis showed no association with asthma risk in the overall populations (Caucasians, Asians, and black people). In subgroup analyses by age, ethnicity, and asthma phenotype, we still did not find any association between the -403G/A polymorphism and asthma.

CONCLUSION

Current findings suggest an association between the -28G allele and asthma risk in Asian children but not in Caucasian children.

Association between RANTES gene polymorphisms and asthma: a meta-analysis

BACKGROUND

A few recent studies have suggested that regulated on activation, normal T cell expressed and secreted (RANTES) polymorphisms (-403 G/A, -28C/G) are associated with asthma. However, there still existed studies which did not confirm these correlations.

OBJECTIVE

The objective of this study was to evaluate the relationship of RANTES and asthma using a meta-analysis.

METHODS

Pubmed, Embase, and Cochrane library databases were systemically searched. Data were extracted by two independent reviewers and pooled odds ratio (OR) with 95% confidence interval (CI) were calculated.

RESULTS

Eighteen studies were enrolled, including a total of 2558 cases and 2630 controls of -403 G/A, as well as 3311 cases and 4031 controls of -28C/G in this meta-analysis. The overall ORs and 95% CIs of -403 G/A were 1.19, 1.06-1.33 (P<0.001) and 1.25, 1.03-1.51 (P = 0.933) in dominant and recessive models, respectively. The overall ORs and 95% CIs of -28G were 1.23, 1.09-1.39 (P = 0.221) and 1.76, 1.32-2.34 (P = 0.356) in dominant and recessive models, respectively. No publication bias among studies was showed.

CONCLUSIONS

This meta-analysis showed that RANTES -403 G/A polymorphism was a risk factor for asthma, while -28C/G polymorphism were not associated with asthma.

Allogeneic splenocyte transfer and lipopolysaccharide inhalations induce differential T cell expansion and lung injury: a novel model of pulmonary graft-versus-host disease

Background

Pulmonary GVHD (pGVHD) is an important complication of hematopoietic cell transplant (HCT) and is thought to be a consequence of the HCT conditioning regimen, allogeneic donor cells, and posttransplant lung exposures. We have previously demonstrated that serial inhaled lipopolysaccharide (LPS) exposures potentiate the development of pGVHD after murine allogeneic HCT. In the current study we hypothesized that allogeneic lymphocytes and environmental exposures alone, in the absence of a pre-conditioning regimen, would cause features of pGVHD and would lead to a different T cell expansion pattern compared to syngeneic cells.

Methods

Recipient Rag1^−/− mice received a transfer of allogeneic (Allo) or syngeneic (Syn) spleen cells. After 1 week of immune reconstitution, mice received 5 daily inhaled LPS exposures and were sacrificed 72 hours after the last LPS exposure. Lung physiology, histology, and protein levels in bronchoalveolar lavage (BAL) were assessed. Lung cells were analyzed by flow cytometry.

Results

Both Allo and Syn mice that undergo LPS exposures (AlloLPS and SynLPS) have prominent lymphocytic inflammation in their lungs, resembling pGVHD pathology, not seen in LPS-unexposed or non-transplanted controls. Compared to SynLPS, however, AlloLPS have significantly increased levels of BAL protein and enhancement of airway hyperreactivity, consistent with more severe lung injury. This injury in AlloLPS mice is associated with an increase in CD8 T cells and effector CD4 T cells, as well as a decrease in regulatory to effector CD4 T cell ratio. Additionally, cytokine analysis is consistent with a preferential Th1 differentiation and upregulation of pulmonary CCL5 and granzyme B.

Conclusions

Allogeneic lymphocyte transfer into lymphocyte-deficient mice, followed by LPS exposures, causes features of pGVHD and lung injury in the absence of a pre-conditioning HCT regimen. This lung disease associated with an expansion of allogeneic effector T cells provides a novel model to dissect mechanisms of pGVHD independent of conditioning.

Association between serotonin transporter gene polymorphisms and childhood asthma

BACKGROUND

Asthma is a common chronic inflammatory disease of the airways in which genetic factors play a major role in its pathogenesis. High serotonin serum levels in patients with asthma suggest that serotonin is involved in the pathophysiology of the disease. Serotonin clearance is mediated by the serotonin reuptake transporter, and functional polymorphisms in this gene lead to altered serotonin reuptake efficiency.

OBJECTIVE

The aim of this study was to investigate the relationship between serotonin transporter gene polymorphisms and asthma.

METHODS

Serotonin transporter gene polymorphisms (5-HTTLPR, rs35521 and STin2.VNTR) were assessed by PCR-based methods in 100 children with mild to moderate persistent asthma and compared with 100 healthy controls.

RESULTS

There were no significant differences in allele, genotype or haplotype frequencies between patients and controls. No association was observed between SERT gene polymorphisms after stratification of patients for sex, age, spirometry indices, family history, passive smoking behavior and concomitant allergic rhinitis. Significant differences were observed in the distribution of 5-HTTLPR alleles (p = 0.025) and genotypes (p = 0.021) between patients with and without atopic dermatitis.

CONCLUSIONS

Despite strong evidence suggesting the role of serotonin in the pathophysiology of asthma, we found no association between serotonin transporter gene polymorphisms and mild to moderate persistent asthma. Further serotonin transporter gene analyses in patients with severe asthma may open up new horizons in the utilization of common serotonin regulators to treat asthma, based on their pharmacogenetic effects. However, serotonin may also be indirectly influenced by emotional stress during asthma attacks.

A disintegrin and metalloprotease 33 (ADAM33) gene polymorphisms and the risk of asthma: a meta-analysis

Polymorphisms in the ADAM33 gene have been associated with asthma, but the data are controversial. Therefore, we reviewed the related studies and quantitatively summarized the associations between ADAM33 polymorphisms and asthma risk using meta-analysis. A dominant model (AA+Aa vs. aa), recessive model (AA vs. Aa+aa), additive model (AA vs. aa) and allelic model (A vs. a) were used to estimate the association between ADAM33 polymorphism and asthma risk. A total of 29 case-control studies referring to 14 SNPs were identified: rs2280091(T1), rs2787094(V4), rs528557(S2), rs2280090(T2), rs511898(F+1), rs44707(ST+4), rs3918396(S1), rs543749(V-1), rs574174(ST+7), rs597980(ST+5), rs2853209(S+1), rs2280089(T+1), rs612709(Q-1), and rs3746631(V5). The results indicated that S1, V-1, V5, S+1, S2, ST+4, ST+7, ST+5, and Q-1 were not associated with asthma. Significant associations were found with the T1, V4, F+1 and T+1 polymorphisms in the overall population. In the subgroup analysis by ethnicity, a positive result was only found for the T1, V4, F+1 and T2 polymorphisms in Asia but not in Europe or Latin America. This meta-analysis provides evidence that the T1, V4, F+1, T2, and T+1 polymorphisms in the ADAM33 gene are risk factors for asthma, especially in the Asian population.