The I/D polymorphism of angiotensin-converting enzyme gene and asthma risk: a meta-analysis

The Effect of Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism on the Severity and Death Rate of COVID-19 in Iranian Patients

The study was designed to assess the association of ACE I/D polymorphism with the severity and prognosis of COVID-19 in the Iranian population. Hence, 186 adult patients were categorized into three clinical groups based on the severity of COVID-19: 1) Outpatients or mildly symptomatic patients as control (n = 71); 2) Hospitalized patients or severe symptomatic cases (n = 53); 3) Inpatients led to ICU/death or critically ill patients needed mechanical ventilation (n = 62). The possible association of ACE I/D polymorphism with the risk of comorbidities and serum level of C-reactive protein was evaluated in two severe cases. The results showed that the frequency of D and I alleles are 69.35% and 30.65%, respectively, in the total population. The analysis of allelic frequencies via Fisher's exact test confirmed significantly higher frequency of D allele in both severe groups than that in the mild one, 78.31% in Hospitalized patients (OR = 2.56; 95% CI 1.46 to 4.46; p-value = 0.0011) and 74.19% in Inpatients led to ICU/death (OR = 2.04; 95% CI = 1.22 to 3.43; p-value = 0.0094) compared to 58.45% in Outpatients. The results of genotype proportions displayed an association between COVID-19 severity and DD genotype. Overall, our findings in Iranian patients supported the undeniable role of the DD genotype in the intensity of the disease, comparable to other populations. Furthermore, there is no definite evidence regarding the protective effect of the I allele in our inquiry.

Angiotensin-converting enzyme 1 gene polymorphisms in patients with systemic sclerosis-associated interstitial lung disease: a single centre retrospective observational study

Angiotensin-converting enzyme (ACE) 1 gene polymorphisms have been associated with vascular permeability, alveolar endothelial dysfunction and fibroblast proliferation and have been studied in pulmonary diseases such as COPD and idiopathic pulmonary fibrosis. Similar mechanisms of ACE 1 polymorphisms have been seen in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD). We are presenting a retrospective observational study in patients with SSc-ILD and analysing the association of ACE 1 gene polymorphisms (DD, II and ID) with the features of SSc, changes in pulmonary function tests (PFTs) and lung HRCT over three different periods of time (at the time of the diagnosis, 5 and 10 years after the diagnosis). The aim of the study was to determine whether ACE 1 gene polymorphisms have an effect on the severity of SSc-ILD. We found no statistically significant differences in the development and severity of SSc-ILD and changes in PFTs between subgroups of ACE 1 gene polymorphism over the analysed periods (at the time of diagnosis HRCT changes p = 0.270, FEV1 p = 0.483, FVC p = 0.497, DLco p = 0.807, after 5 years HRCT changes p = 0.163, FEV1 p = 0.551, FVC p = 0.362, DLco p = 0.620 and 10 years of follow-up HRCT changes p = 0.853, FEV1 p = 0.589, FVC p = 0.328, DLco p = 0.992). However, patients with the ID genotype showed a significant reduction in FEV1 after 10 years of follow-up in comparison to baseline levels (91.0 (IR 80.0-105.0) at the time of diagnosis and 84.0 (IR 69.0-99.0) after 10 years, p = 0.014). Our study suggests that ACE 1 gene polymorphisms do not have a role in the severity of SSc-ILD. Further studies are needed to explain the exact role of ACE 1 gene polymorphisms in SSc-ILD and SSc in general.

Genetically high angiotensin-converting enzyme concentrations causally increase asthma risk: A meta-analysis using Mendelian randomization

Objectives

This meta-analysis aimed to test the association of angiotensin-converting enzyme (ACE) gene I/D polymorphism with asthma risk and circulating ACE changes.

Methods

Public literature retrieval, publication selection, and information extraction were completed independently by two investigators. Effect-size values are expressed as odds ratios (ORs) or standardized mean differences (SMDs) with a 95% confidence interval (95% CI).

Results

Nineteen studies (2,888 patients and 9,549 controls) fulfilled the eligibility criteria. Overall investigations demonstrated that ACE gene I/D polymorphism was significantly associated with asthma risk under allelic (OR, 95% CI: 1.26, 1.08 to 1.48), homozygous genotypic (1.50, 1.09 to 2.06), and recessive (1.53, 1.24 to 1.89) models with moderate heterogeneity (I2 statistic: 64% to 79%). Subsidiary investigations recorded that race, matched status, asthma diagnosis, sample size, and age possibly accounted for the existence of significant heterogeneity. Relative to carriers with the II genotype, those with the DD genotype, ID genotype, and the combination of DD and ID genotypes had significantly higher concentrations of circulating ACE (WMD: 3.13, 2.07, and 2.83 U/L, respectively, p < 0.05). Adoption of Mendelian randomization analyses revealed that one unit increment in circulating ACE concentrations was found to be significantly associated with a 1.14-fold increased risk of asthma (95% CI: 1.02 to 4.24).

Conclusion

We provided strong meta-analytical evidence supporting the causal implication of high circulating ACE concentrations in the development of asthma.

Angiotensin-converting enzyme insertion/deletion polymorphism and susceptibility to pediatric asthma: A meta-analysis

Objective:

The correlation of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with pediatric asthma risk was assessed in this meta-analysis.

Methods:

PubMed, Web of Science, Embase and CNKI databases were systematically searched for relevant literature, followed by application of odds ratios (OR) along with 95% confidence interval (CI) for determining the strength of relationship.

Results:

Seven articles with 802 cases and 632 controls fulfilled the inclusion criteria. As a result, the ACE I/D polymorphism was related to elevated pediatric asthma risk (D vs I: OR = 1.87, 95% CI = 1.59–2.20; dominant model: OR =1.53, 95% CI = 1.28–1.81; recessive model: OR =1.54, 95% CI = 1.28–1.85; DD vs II: OR =2.95, 95% CI = 2.19–3.98; DI vs II: OR = 0.96, 95% CI = 0.78–1.19). Subgroup analysis stratified by race revealed significant interrelation in Asians.

Conclusion:

This meta-analysis demonstrated that the ACE I/D polymorphism might be related to the risk of pediatric asthma.

Common Variants of Vitamin D Receptor Gene Polymorphisms and Susceptibility to Coronary Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

ApaI, FokI, TaqI, and BsmI polymorphisms in the vitamin D receptor (VDR) gene have been reported to be associated with the risk of coronary artery disease (CAD), although the results of previous studies have been inconsistent. The aim of this study was to explore whether these polymorphisms play a role in the genetic susceptibility to CAD.

METHODS

A comprehensive search of Medline and Embase databases was conducted for studies evaluating the association between the VDR polymorphisms and CAD risk. Odds ratios with 95% confidence intervals were calculated to assess the strength of association in the dominant model, recessive model, allelic model, and genotypes contrast.

RESULTS

Nine studies involving a total of 5,259 cases and 1,981 controls were finally included in this meta-analysis. Overall, no significant associations were found between ApaI, FokI, TaqI, and BsmI polymorphisms and the risk of CAD in any of the genetic models (all p ˃ 0.05). Moreover, a subgroup analysis by ethnicity did not reveal a significant relationship between any of the examined polymorphisms and CAD risk in Caucasians and East-Asians for any model (all p ˃ 0.05).

CONCLUSION

Current evidence suggests that the ApaI, FokI, TaqI, and BsmI polymorphisms of the VDR gene might not be associated with genetic susceptibility to CAD. Further well-designed studies with large sample sizes are needed to confirm our results.

An angiotensin I-converting enzyme insertion/deletion polymorphism is associated with Pakistani asthmatic cases and controls

Asthma is a chronic disease due to inflammation of the airways of lungs that is clinically characterized by variable symptoms including wheezing, coughing and shortness of breath. Angiotensin I-converting enzyme (ACE) plays a major role in fibrous tissue formation and is highly expressed in lungs. The main aim of this research work was to study the role of ACE insertion/deletion (I/D) polymorphism, rs4646994, in asthma in Pakistani patients. A total of 854 subjects, including 333 asthma patients and 521 ethnically matched controls, were studied. The ACE (I/D) polymorphism was genotyped using polymerase chain reaction (PCR). Chi-square, Fisher's exact and Hardy-Weinberg equilibrium tests were used to compare groups. Homozygous insertion genotype II (p less than 0.0001, OR=3.38) and insertion allele (I) was significantly more frequent in Pakistani asthmatics than in healthy controls (p=0.0007, OR=1.40). The ID genotype (p less than 0.0001, OR=0.43) and the deletion allele (D) were associated with protection of disease in Pakistani patients (p=0.0007, OR=0.71). These data suggest the involvement of ACE I/D polymorphism in asthma risk in the Pakistani population. This marker may be an important indication in the molecular mechanism of asthma and can become a useful tool in risk assessment and help in designing strategy to combat disease.

Association between allergic diseases and risks of HSP and HSP nephritis: a population-based study

BACKGROUND

Some allergic inflammation-associated mediators have been reported in acute stage of Henoch-Schönlein purpura (HSP). However, the association of children with allergic diseases and their subsequent risks of HSP and HSP nephritis remain unknown.

METHODS

In this study, we included 2,240 children with HSP diagnosed between 2000 and 2008 as well as 8,960 non-HSP controls matched for age, sex, and level of urbanization. The odds ratios (ORs) of HSP were calculated with respect to associations with pre-existing allergic diseases.

RESULTS

Children with allergic diseases had an increased subsequent risk of HSP; the lowest adjusted OR (aOR) was 1.33 for allergic conjunctivitis (95% confidence interval (CI): 1.17-1.52) and the highest was 1.68 for asthma (95% CI: 1.48-1.91). The aOR increased to 2.03 (95% CI: 1.80-2.31) in children with at least two allergic diseases. Children who visited medical institutes more often per year for associated allergic diseases had an increased risk of HSP. Of the 2,240 children with HSP, 249 (11%) had HSP nephritis and 45.8% of those with nephritis had history of any allergic disease.

CONCLUSION

Atopic children had an increased subsequent risk of HSP but not an increased risk of HSP nephritis.

Maternal exposure to fine particulate matter (PM2.5) and pregnancy outcomes: a meta-analysis

A growing body of evidence has investigated the association between maternal exposure to PM2.5 (particulate matter with aerodynamic diameter 2.5 μm) during pregnancy and adverse pregnancy outcomes. However, the results of those studies are not consistent. To synthetically quantify the relationship between maternal exposure to PM2.5 during pregnancy and pregnancy outcomes (the change in birth weight, low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), and stillbirth), a meta-analysis of 25 published observational epidemiological studies that met our selection criteria was conducted. Results suggested a 10 μg/m(3) increase in PM2.5 was positively associated with LBW (odds ratio (OR) = 1.05; 95 % confidence interval (CI), 1.02-1.07), PTB (OR = 1.10; 95 % CI, 1.03-1.18), and SGA (OR = 1.15; 95 % CI, 1.10-1.20) based on entire pregnancy exposure, and pooled estimate of decrease in birth weight was 14.58 g (95 % CI, 9.86-19.31); however, there was no evidence of a statistically significant effect of per 10 μg/m(3) increase in PM2.5 exposure on the risk of stillbirth (OR = 1.18; 95 % CI, 0.69-2.04). With respect to three different gestation periods, no significant risks were found in PTB, stillbirth, and the first trimester on the change of birth weight with a 10 μg/m(3) increase in PM2.5. In this study, a comprehensive quantitative analysis of the results show that PM2.5 can increase the risk of LBW, PTB, and SGA; pregnant women need to take effective measures to reduce PM2.5 exposure.

Angiotensin-converting enzyme gene insertion/deletion polymorphisms and the susceptibility to allergic rhinitis

BACKGROUND

Angiotensin-converting enzyme (ACE) gene I/D polymorphism might be linked to the risk of the allergic rhinitis (AR).

OBJECTIVE

In the present study, we assessed the association of ACE gene I/D polymorphisms with AR susceptibility using a meta-analysis.

MATERIALS AND METHODS

We carried out a retrieval of studies and included the eligible studies if they met the criteria. After the data extraction, the Stata software was used to analyse the genotype frequencies.

RESULTS

In total, five studies with 561 patients and 603 controls were included. However, the genotype distribution among the control of one study was not consistent with the Hardy-Weinberg equilibrium. After pooling all studies, the results indicated an association between ACE gene I/D polymorphism and AR risk in the overall analysis (II vs. others: OR=0.70, 95% CI=0.54-0.92, P=0.010; D vs. I: OR=1.29, 95% CI=1.08-1.54, P=0.005). In the further analysis of the East Asians, no association between ACE gene I/D polymorphism and AR risk was observed.

CONCLUSION

ACE gene I/D polymorphisms were not associated with the risk of AR in East Asians. These results need to be confirmed in the following studies.

A meta-analysis of P2X7 gene-762T/C polymorphism and pulmonary tuberculosis susceptibility

AIM

We performed a comprehensive meta-analysis to determine the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis susceptibility.

METHODOLOGY

Based on comprehensive searches of the PubMed, SCI, Elsevier, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis risk. Pooled odds ratio (ORs) and 95% confidence intervals (95%CIs) were calculated in random-effects model.

RESULTS

A total of 2207 tuberculosis cases and 2220 controls in 8 case-control studies were included in this meta-analysis. Allele model (C vs. T: p = 0.15; OR = 0.83, 95% CI = 0.65-1.07), homozygous model (CC vs. TT: p = 0.23; OR = 0.73, 95% CI = 0.44 to 1.22), and heterozygous model (CT vs. TT: p = 0.57; OR = 0.92, 95% CI = 0.68 to 1.24) did not show increased risk of developing pulmonary tuberculosis. Similarly, dominant model (CC+CT vs. TT: p = 0.32; OR = 0.84, 95% CI = 0.59 to 1.19) and recessive model (CC vs. CT+TT: p = 0.08; OR = 0.77, 95% CI = 0.57 to 1.04) failed to show increased risk of developing pulmonary tuberculosis. Subgroup analysis by ethnicity did not detect any significant association between P2X7-762T/C polymorphism and pulmonary tuberculosis susceptibility.

CONCLUSIONS

P2X7 -762T/C gene polymorphism is not associated with pulmonary tuberculosis susceptibility.

The Glu298Asp polymorphism in the NOS3 gene and the risk of prostate cancer

The Glu298Asp polymorphism in the NOS3 gene has been implicated as a risk factor for prostate cancer. To date, several studies have evaluated the associations between the Glu298Asp polymorphism and prostate cancer risk; however, the results were inconclusive. The aim of the current study was to perform a meta-analysis to investigate the association between the polymorphism and the risk of prostate cancer. A total of 3,206 cases and 3,880 controls from eight case-control studies were included for data synthesis. The overall results suggested no significant association between the polymorphism and the risk of prostate cancer (OR=1.01, 95% CI=0.92-1.11, p = 0.83 for Asp/Asp+Glu/Asp vs. Glu/Glu). In the stratified analysis according to ethnicity, no significant associations were observed in Asians and Europeans. The current meta-analysis suggested that the Glu298Asp polymorphism of the NOS3 gene might not contribute to the risk of prostate cancer.

The Val158Met polymorphism in the COMT gene is associated with increased cancer risks in Chinese population

The Val158Met polymorphism in the COMT gene may affect the DNA repair pathways and be associated with the risk of cancer in Chinese population. However, the results of previous studies are inconsistent. The objective of this study was to investigate the association between the Val158Met polymorphism in the COMT gene and the risk of cancer for Chinese population by meta-analysis. We searched PubMed, Embase, CNKI, Weipu, and Wanfang databases, and the last search was updated on Sep. 26, 2013. Statistical analysis was performed using the Revman4.2 and Stata10.0 software. A total of 18 case-control studies concerning 5034 case and 6234 controls were included. In the total analysis, the results suggested a significant association between the Val158Met polymorphism in the COMT gene and the cancer risk in Chinese population: OR = 1.34, 95%CI = 1.04-1.73, and P = 0.03 for AA vs. AG + GG; OR = 1.39, 95%CI = 1.06-1.82, and P = 0.02; OR = 1.13, 95%CI = 1.01-1.27, and P = 0.04. In the subgroup analysis by cancer types, significant association was found in the breast cancer and esophageal squamous cell carcinoma. The current meta-analysis confirmed that the Val158Met polymorphism in the COMT gene may be a risk factor for cancer in Chinese population. In the future, more case-control studies are needed to validate our results.

The association between the C-509T and T869C polymorphisms of TGF-β1 gene and the risk of asthma: a meta-analysis

Asthma is a complex multigenic disease in which gene-environment interactions play a critical role in disease onset and progression. Transforming growth factor-β1 (TGF-β1) is one of several candidate locus for the pathogenesis of asthma, and is highly polymorphic. To derive a more precise estimation of the relationship between the T869C and C-509T polymorphisms of the TGF-β1 gene and asthma, a meta-analysis of 24 published case-control studies was conducted. 20 studies for C-509T polymorphism and 8 studies for T869C polymorphism were included. The pooled odds ratios were calculated respectively for allele contrasts, additive genetic model, dominant genetic model and recessive genetic model. Subgroup analyses were also performed by ethnicity, age, atopic status and asthma severity for two gene polymorphisms. In regard to T869C polymorphism, significant associations with asthma were observed in recessive (OR 1.23, 95%CI 1.00-1.51 and P=0.047), additive and allele models. In the subgroup analysis by age, significant risks were also found in the recessive model for adults (OR 1.31, 95%CI 1.02-1.69 and P=0.032), atopic asthma (OR 1.63, 95%CI 1.07-2.49 and P=0.023). With respect to C-509T polymorphism, significant associations with asthma were demonstrated in the overall analysis and subgroup analyses in the dominant model for Asian (OR 1.37, 95%CI 1.04-1.81 and P=0.025), Adults (OR 1.26, 95%CI 1.02-1.56 and P=0.035), Children (OR 1.19, 95%CI 1.01-1.40 and P=0.034). Potentially functional TGF-β1 C-509T and T869C polymorphisms may be risk factors for asthma susceptibility.

The associations between the polymorphisms in the CTLA-4 gene and the risk of Graves' disease in the Chinese population

Background

The associations between the polymorphisms in Cytotoxic T lymphocyte-associated molecule-4 (CTLA-4) gene and Graves’ disease (GD) have been extensively investigated in Chinese population. However, the results were inconsistent. The objective of this study is to investigate the associations between the polymorphisms in CTLA-4 gene and the risk of GD by meta-analysis.

Methods

We searched Pubmed database, Medline (Ovid) database, CNKI database and Wanfang database, covering all studies until August 11, 2012. Statistical analysis was performed by using the Revman4.2 software and the Stata10.0 software.

Results

A total of 28 case–control studies concerning the most widely studied three polymorphisms [+49A/G(rs231775), -318C/T(rs5742909) and CT60(rs3087243)] for Chinese population in 21 publications were included. The results suggested that the G allele carriers (GG+GA) might have an increased risk of GD when compared with the AA homozygote carriers for the +49A/G polymorphism (GG+GA vs. AA: OR = 2.57, 95%CI = 1.87-3.52). However, as to the -318C/T polymorphism and CT60 polymorphism, the results indicated that the variant allele carriers might have decreased risks of GD when compared with the homozygote carriers (−318C/T: TT+TC vs. CC: OR = 0.78, 95%CI = 0.62-0.97; CT60: AA+AG vs. GG: OR = 0.64, 95%CI = 0.52-0.78).

Conclusions

The current meta-analysis indicated that the polymorphisms in the CLTA-4 gene might be risk factors for GD in the Chinese population. In future, more large-scale case–control studies are needed to validate these results.

The -590C/T polymorphism in the IL-4 gene and the risk of cancer: a meta-analysis

Interleukin-4 (IL-4) plays an important role in the pathogenesis of cancer. The -590C/T polymorphism in the IL-4 gene has been implicated in susceptibility to cancer, but the results have been inconclusive. The aim of this study was to analyze the association between this polymorphism with the risk of cancer by meta-analysis. PubMed, Embase, CNKI, and Wanfang databases were searched for all publications concerning the association between this polymorphism and cancer risk. Statistical analyses were analyzed by using RevMan 4.2 and STATA10.0 softwares. A total of 8,715 cases and 9,532 controls in 23 case-control studies were included. The results suggested that there was no significant association between IL-4 -590C/T polymorphism and cancer risks (TT + TC vs. CC: OR = 0.97, 95 % CI = 0.90-1.04, P = 0.36). In the subgroup analysis by ethnicity, no significant association was detected in Asians and Caucasians. In the subgroup analysis by cancer types, no significant association was found in gastric cancer and colorectal cancer. The current meta-analysis suggested that the -590C/T polymorphism in the IL-4 gene might not be associated with increased/decreased risk of cancer. The -590C/T polymorphism might be not a risk factor for cancers.

Plasminogen activator inhibitor-1 and angiotensin converting enzyme gene polymorphisms in Turkish asthmatic children

BACKGROUND

Polymorphisms of plasminogen activator inhibitor-1 (PAI-1) and angiotensin-converting enzyme (ACE) genes have been implicated in susceptibility to asthma. In this study, we aimed to investigate whether there was any association between childhood asthma and polymorphisms of the PAI-1 and ACE genes.

METHODS

Two hundred and three Turkish children aged 5-15 years, including 102 asthmatic patients and 101 healthy control subjects were included in this study. The asthma group was divided into two groups as follows: Group I: Asthmatic children with positive family history for atopy (n=53), Group II: Asthmatic children without any family history for atopy (n=49). One hundred and twenty-eight atopic family members were also included in the study. The insertion/deletion (I/D) polymorphism of the ACE and PAI-1 4G/5G gene polymorphisms was carried out by polymerase chain reaction.

RESULTS

The prevalence of the PAI-1 4G allele was significantly greater in asthmatic children compared to control group (p<0.05, OR: 1.64 (1.11-2.43)) but there was no significant relation between ACE I/D genotypes and childhood asthma. No significant difference was detected between Groups I and II in terms of these ACE and PAI-1 genotypes and allele frequencies. No significant relationship was found between both gene polymorphisms and total serum IgE and skin prick test results.

CONCLUSION

It has been established that PAI-1 4G allele may be a genetic risk factor for childhood asthma but ACE gene I/D polymorphisms do not play a role in the development of asthma in the sample of Turkish children.

The -444A/C polymorphism in the LTC4S gene and the risk of asthma: a meta-analysis

BACKGROUND AND AIMS

The -444A/C polymorphism in the leukotriene C4 synthase (LTC4S) gene has been implicated in susceptibility to asthma, but a large number of studies have reported inconclusive results. The aim of this study was to investigate the association between the -444A/C polymorphism in the LTC4S gene and asthma risk using meta-analysis.

METHODS

We searched Pubmed, Embase, CNKI and Wanfang databases. Statistical analysis was performed using the software Revman4.2 and STATA10.0.

RESULTS

A total of 3042 cases and 1902 controls in 13 case-control studies were included in the meta-analysis. The results indicated that the variant C allele carriers (CC + AC) did not have increased/decreased risk of asthma when compared with the homozygote AA (CC + AC vs. AA: OR = 1.13, 95% CI = 1.00-1.28, p = 0.06). In the subgroup analysis by age, ethnicity and aspirin sensitivity, significantly elevated risks were found only in Caucasians (OR = 1.21, 95% CI = 1.02-1.44, p = 0.03) and aspirin-tolerant populations (OR = 1.36, 95% CI = 1.12-1.65, p = 0.002) but not in other subgroups.

CONCLUSIONS

This meta-analysis suggested that the -444A/C polymorphism in the LTC4S gene would be a risk factor for asthma in Caucasians and aspirin-tolerant populations. Future studies are needed to validate our results.

The D/I polymorphism in the angiotensin-converting enzyme gene and chronic obstructive pulmonary disease risk: a meta-analysis

BACKGROUND

The deletion/insertion (D/I) polymorphism in the angiotensin-converting enzyme (ACE) gene has been implicated in susceptibility of chronic obstruction pulmonary disease (COPD), but a number of studies have reported inconclusive results. The aim of this study is to investigate the relationship between the D/I polymorphism in the ACE gene and COPD risk by meta-analysis.

METHOD

We searched Pubmed database, Embase database, CNKI database and Wanfang database, covering all studies until October 10, 2011. Statistical analysis was performed by using the software Revman4.2 and STATA 10.0.

RESULTS

A total of 710 COPD cases and 862 controls in 10 case-control studies were included in this study. The results suggested that the DD homozygote carriers did not have an increased or decreased risk of COPD when compared with the heterozygote DI and II homozygote carriers. However, in the subgroup analysis by race, significant increased risks were found in Asian DD homozygote carriers (OR = 2.6 and 95% CI = 1.47-4.57 for DD vs. DI+II) but not in Caucasian DD homozygote carriers (OR = 0.91, 95%CI = 0.69-1.22, P = 0.54 for DD vs. DI+II).

CONCLUSIONS

This meta-analysis suggested that the ACE gene is a COPD susceptible gene in Asian populations. Future studies are needed to validate our conclusions..

The -2518A/G polymorphism in the MCP-1 gene and tuberculosis risk: a meta-analysis

Background

The -2518A/G polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene has been implicated in the susceptibility to tuberculosis (TB), but the results are not conclusive. The aim of this study is to investigate the association between the -2518A/G polymorphism in the MCP-1 gene and the risk of tuberculosis by meta-analysis.

Methods

We searched Pubmed, Embase, CNKI and Wanfang databases, covering all studies until April 29^th, 2011. Statistical analyses were performed using the Revman4.2 and STATA10.0 software.

Results

A total of 5341 cases and 6075 controls in 13 case-control studies were included in the meta-analysis. The results indicated that the GG homozygote carriers had a 67% increased risk of TB compared with the A allele carriers (GG vs. GA+AA: OR = 1.67, 95%CI = 1.25–2.23, P = 0.0006). In the subgroup analysis by ethnicity, significant elevated risks were found in Asians and Latinos, but not in Africans (GG vs. GA+AA: OR = 1.79, 95%CI = 1.19–2.70 and P = 0.005 for Asians; OR = 2.15, 95%CI = 1.32–3.51 and P = 0.002 for Latinos; OR = 1.28, 95%CI = 0.45–3.64 and P = 0.65 for Africans).

Conclusion

This meta-analysis suggested that the -2518A/G polymorphism of MCP-1 gene would be a risk factor for TB in Asians and Latinos, while not in Africans.

Association between angiotensin-converting enzyme I/D polymorphism and asthma risk: a meta-analysis involving 11,897 subjects

BACKGROUND

Genetic susceptibility to asthma has been a research focus in the scientific community. Several studies have been conducted in recent years to evaluate the risk of asthma and insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE). However, the results remain conflicting rather than conclusive.

METHODS

We carried out a search in Medline, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) database for relevant studies. Data were extracted using a standardized form and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association.

RESULTS

Our meta-analysis on 11,897 subjects from all available studies showed that the DD genotype was associated with increased asthma risk than those with the II (OR = 1.59, 95% CI = 1.20-2.12) or ID/II (OR = 1.62, 95% CI = 1.24-2.10) genotype. Stratified analyses by ethnicity (Europeans and Asians) and age (adults and children) obtained statistically similar results in the two genetic models. In the subgroup analysis by source of controls, the DD genotype was associated with a significantly elevated risk of asthma among population-based controls (DD vs. II: OR = 2.27, 95% CI = 1.45-3.56) but not hospital-based controls (DD vs. II: OR = 1.18, 95% CI = 0.93-1.49).

CONCLUSIONS

This meta-analysis provides strong evidence that the I/D polymorphism of ACE is associated with asthma risk. Additional well-designed large studies were required for the validation of our results, especially in African populations.

Polymorphisms in the vitamin D receptor gene and type 1 diabetes mellitus risk: an update by meta-analysis

Four well known polymorphisms (BsmI, FokI, ApaI, TaqI) in the VDR gene have been implicated in susceptibility to type 1 diabetes mellitus (T1DM), but the results to date have been inconclusive. The aim of this study was to investigate the association between polymorphisms in the VDR gene and T1DM risk by meta-analysis. A total of 57 case-control studies in 26 published studies were included. The results indicated that the BsmI polymorphism is associated with increased risk of T1DM (BB+Bb vs. bb: OR=1.30, 95% CI=1.03-1.63), while the FokI, ApaI and TaqI polymorphisms were not. In the subgroup analysis by ethnicity, the increased risk of T1DM remained in the Asian subgroup for the BsmI polymorphism; whereas no significant association was found in other populations for other polymorphisms. Results from the current study suggest that the BsmI polymorphism is associated with increased risk of T1DM, especially in Asians. Further studies are needed to confirm our results.

The +874T/A polymorphism in the interferon-γ gene and tuberculosis risk: an update by meta-analysis

The +874T/A polymorphism in the interferon-γ (IFN-γ) gene has been extensively examined for association to tuberculosis (TB); however, results of different studies have been inconsistent. The aim of this study was to comprehensively analyze the genetic risk of the +874T/A polymorphism in IFN-γ gene for TB by meta-analysis. A total of 4553 cases and 4631 controls in 21 case-control studies were included in this meta-analysis. The results indicated that the variant T allele carriers had a 27% decreased risk of TB, when compared with the homozygote AA (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.61-0.87 for TT + TA versus AA). In the subgroup analysis by ethnicity, significant decreased risks were associated with T allele carriers in Asians (OR= 0.71, 95% CI = 0.52-0.97, p = 0.03) but not in Caucasians (OR = 0.87, 95% CI = 0.65-1.17, p = 0.37). Our results suggest that the IFN-γ +874T/A polymorphism contributes to susceptibility to TB.

Angiotensin-converting enzyme polymorphism affects outcome of local Chinese with acute lung injury

INTRODUCTION

Acute Lung Injury (ALI) with genetic predisposition is fatal. Relationship between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and the prognosis of local Chinese patients with ALI was investigated; meanwhile, the mechanisms involved were explored.

METHODS

101 ALI patients, 408 non-ALI patients and 236 healthy blood donors were enrolled. ACE I/D polymorphism was detected by polymerase chain reaction, then ACE genotype (II, ID, DD) and allele (I, D) frequencies were compared. Clinical data of ALI patients was calculated. Also, peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers with different ACE genotypes. Lipopolysaccharide (LPS)-induced ACE gene mRNA expression and ACE activity was measured.

RESULTS

There was no significant difference in the frequencies of the genotypes and alleles. Acute Physiology and Chronic Health Evaluation (APACHE) II score was higher in DD subgroup than in II subgroup (19.7 ± 8.7 and 15.6 ± 6.2; P < 0.05). The 28-day mortality was significantly different (17.4%, 26.8%, and 64.3% for II, ID, and DD; P = 0.013). DD genotype was the independent prognostic factor for 28-day outcome. Furthermore, LPS-induced ACE mRNA expression and ACE activity from PBMC in DD genotype subgroup were both significantly higher than those in the other two subgroups.

CONCLUSIONS

ACE I/D polymorphism is a prognostic factor for ALI. Patients with the DD genotype have higher mortality of ALI. Polymorphism influences the expression of ACE gene in LPS-stimulated PBMC, DD genotype leads to higher level of mRNA and enzyme activity. It may be one of the mechanisms involved.

The association between angiotensin-converting enzyme insertion/deletion gene variant and risk of focal segmental glomerulosclerosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The association of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism with the risk of focal segmental glomerulosclerosis (FSGS) is still controversial. A meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and FSGS susceptibility.

METHOD

We performed a predefined literature search and selection of eligible relevant studies to collect data from electronic databases.

RESULTS

In total, 12 articles were identified for the analysis of the association between ACE I/D gene polymorphism and FSGS risk. One report included an investigation in Arab and Jewish populations separately. Thus, there were seven reports in Asians, two in Caucasians, one in Africans, two in Arabs and one in Jews. In Asians, there was a markedly positive association between the D allele or DD genotype and FSGS susceptibility (p = 0.008; p = 0.002), and the II genotype may play a protective role against FSGS onset (p = 0.002). However, a link between ACE I/D gene polymorphism and FSGS risk was not found in Caucasians, Africans, Arabs or Jews (Caucasians: D: p = 0.11, DD: p = 0.19, II: p = 0.70; Africans: D: p = 0.40, DD: p = 0.49, II: p = 0.61; Arabs: D: p = 0.34, DD: p = 0.10, II: p = 0.42; Jews: D: p = 0.90, DD: p = 0.97, II: p = 0.83).

CONCLUSION

The D allele or DD homozygosity may become a significant genetic molecular marker for the onset of FSGS in Asians, but not for Caucasians, Africans, Arabs or Jews.

ACE I/D gene polymorphism can't predict the steroid responsiveness in Asian children with idiopathic nephrotic syndrome: a meta-analysis

Background

The results from the published studies on the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and the treatment response to steroid in Asian children with idiopathic nephrotic syndrome (INS) is still conflicting. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and treatment response to steroid in Asian children and to explore whether ACE D allele or DD genotype could become a predictive marker for steroid responsiveness.

Methodology/Principal Findings

Association studies were identified from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) as of September 1, 2010, and eligible investigations were synthesized using meta-analysis method. Five investigations were identified for the analysis of association between ACE I/D gene polymorphism and steroid-resistant nephrotic syndrome (SRNS) risk in Asian children and seven studies were included to explore the relationship between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) susceptibility. Five investigations were recruited to explore the difference of ACE I/D gene distribution between SRNS and SSNS. There was no a markedly association between D allele or DD genotype and SRNS susceptibility or SSNS risk, and the gene distribution differences of ACE between SRNS and SSNS were not statistically significant. II genotype might play a positive role against SRNS onset but not for SSNS (OR = 0.51, P = 0.02; OR = 0.95, P = 0.85; respectively), however, the result for the association of II genotype with SRNS risk was not stable.

Conclusions/Significance

Our results indicate that D allele or DD homozygous can't become a significant genetic molecular marker to predict the treatment response to steroid in Asian children with INS.

Relationship between Angiotensin-Converting Enzyme Insertion/Deletion Gene Polymorphism and Susceptibility of Minimal Change Nephrotic Syndrome: A Meta-Analysis

Aim. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and MCNS susceptibility. Method. A predefined literature search and selection of eligible relevant studies were performed to collect the data from electronic databases. Results. Six articles were identified for the analysis of association between ACE I/D gene polymorphism and MCNS risk, including 4 for Asians, one in Caucasian population and one for Africans. There was a markedly positive association between D allele or DD genotype and MCNS susceptibility in Asians (D: P = .01, DD: P = .02), but not for Caucasians and Africans (Caucasians: D: P = .16, DD: P = .98; Africans: D: P = .81, DD: P = .49). Furthermore, the II genotype seemed not to play a protective role against MCNS risk for Asians, Caucasians and Africans (P = .12, P = .09, P = .76, resp.). Interestingly, there was also significant association between ACE I/D gene polymorphism and MCNS susceptibility in overall populations (D: P = .007, DD: P = .04, II: P = .03). Conclusion. D allele or DD genotype might be a significant genetic molecular marker for MCNS susceptibility in Asians and overall populations, but not for Caucasians and Africans. More larger and rigorous genetic epidemiological investigations are required to further explore this association.

The -308 G/A polymorphism in TNF-α gene is associated with asthma risk: an update by meta-analysis

BACKGROUND

The -308 G/A polymorphism in TNF-α gene has been extensively investigated for association to asthma; however, results of different studies have been inconsistent. The aim of this study is to comprehensively evaluate the genetic risk of -308 G/A polymorphism in TNF-α gene for asthma.

METHODS

A meta-analysis was carried out to analyze the association between the -308 G/A polymorphism TNF-α gene and asthma risk.

RESULTS

A total of 4717 cases and 5012 controls in 29 case-control studies were included in this meta-analysis. The result indicated that the variant A allele carriers had a 38% increased risk of asthma, when compared with the homozygote GG (odds ratio (OR) = 1.40, 95% confidence interval (CI), 1.13-1.68 for AA + AG vs. GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with A allele carriers in Asians (OR = 1.53, 95% CI = 1.17-2.01 and P = 0.002) but not in Caucasians(OR = 1.06, 95% CI = 0.75-1.50 and P = 0.73). In the subgroup analysis by age, significant elevated risks were associated with A allele carriers in adults (OR = 1.44, 95% CI = 1.14-1.81, and P = 0.002) and children (OR = 1.37, 95% CI = 1.03-1.82, and P = 0.003). In the subgroup analysis by atopic status, significant elevated risks of asthma were associated with A allele carriers in atopic population (OR = 1.68, 95% CI = 1.34-2.10, and P < 0.00001) but not in non-atopic population (OR = 0.98, 95% CI = 0.58-1.68, and P = 0.95).

CONCLUSIONS

Our results suggest that the TNF-α -308 G/A polymorphism contributes to susceptibility to asthma.