Angiotensin-converting enzyme insertion/deletion polymorphism and risk and outcome of pneumonia

Impact of ACE I gene insertion/deletion, A-240T polymorphisms and the renin-angiotensin-aldosterone system on COVID-19 disease

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic is driven by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which has led to an enormous burden on patient morbidity and mortality. The renin-angiotensin-aldosterone system (RAAS) plays a significant role in various pulmonary diseases. Since SARS-CoV-2 utilizes the angiotensin-converting enzyme (ACE)2 receptor to exert its virulence and pathogenicity, the RAAS is of particular importance in COVID 19.

METHODS

Our preliminary study investigates retrospectively the influence of selected ACE-polymorphisms (I/D location at intron 16 in the B-coding sequence (rs4646994) and A-240T (rs 4291) at the A-promoter) as well as ACE1 and ACE2 serum levels on disease severity and the inflammatory response in inpatients and outpatients with COVID-19.

RESULTS

Our study included 96 outpatients and 88 inpatients (65.9% male, mean age 60 years) with COVID-19 from April to December 2020 in four locations in Germany. Of the hospitalized patients, 88.6% participants were moderately ill (n = 78, 64% male, median age 60 years), and 11.4% participants were severely ill or deceased (n = 10, 90% male, median age 71 years). We found no polymorphism-related difference in disease, in age distribution, time to hospitalization and time of hospitalization for the inpatient group. ACE1 serum levels were significantly increased in the DD compared to the II polymorphism and in the TT compared to the AA polymorphism. There was no significant difference in ACE 1 serum levels l between moderately ill and severely ill patients. However, participants requiring oxygen supplementation had significantly elevated ACE1 levels compared to participants not requiring oxygen, with no difference in ACE2 levels whereas females had significantly higher ACE2 levels.

CONCLUSIONS

Although there were no differences in the distribution of ACE polymorphisms in disease severity, we found increased proinflammatory regulation of the RAAS in patients with oxygen demand and increased serum ACE2 levels in women, indicating a possible enhanced anti-inflammatory immune response.

CLINICAL TRIAL REGISTRATION

PreBiSeCov: German Clinical Trials Register, DRKS-ID: DRKS00021591, Registered on 27th April 2020.

Role of ACE2 polymorphism in COVID-19: impact of age

More than 2 million people have died as a result of the COVID-19 outbreak. Angiotensin-converting enzyme 2 (ACE2) is a counter-regulatory enzyme that converts angiotensin-2 to Ang-(1-7) form in the renin-angiotensin system. Several studies have been analyzed the correlation between ACE2 and COVID-19. Indeed, ACE2/Ang (1-7) system protects the lung against acute respiratory distress syndrome by its anti-inflammatory/anti-oxidant function. However, SARS-Cov-2 can use ACE2 for host cell entry. Expression of ACE2 can be altered by several factors, including hypertension, diabetes and obesity, which also could increase the severity of COVID-19 infection. Besides, since androgens increase the expression of ACE-2, males are at higher risks of COVID-19 infection. Although reported statistics showed a significantly different infection risks of COVID-19 between adults and children, the reason behind the different responses is still unclear. This review proposes the effect of ACE polymorphism on the severity of SARS-COV-2 induced pneumonia. The previous meta-analysis regarding the effect of ACE polymorphism on the severity of pneumonia showed that polymorphism only affects the adult's illness severity and not the children. Two recent meta-analyses examined the effect of ACE polymorphism on the prevalence and mortality rate of COVID-19 and reported contradicting results. Our opinion paper suggests that the effect of ACE polymorphism on the severity of COVID-19 depends on the patients age, same as of the pneumonia.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in Egyptian children with CAP: A case-control study

BACKGROUND

Community-acquired pneumonia (CAP) is a major cause of childhood morbidity and mortality worldwide. The angiotensin-converting enzyme (ACE) gene is a potential candidate gene for CAP risk.

OBJECTIVES

In this study, we aimed to investigate whether the ACE insertion/deletion (I/D) polymorphism (rs4340) could be a genetic marker for CAP susceptibility in Egyptian children, and we also measured the serum ACE level to assess its relation to such polymorphism.

METHODS

This was a prospective case-control study included 300 patients with CAP, and 300 age, gender, and ethnicity matched healthy controls. The ACE I/D polymorphism (rs4340) at intron 16 was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while the serum ACE levels were measured by ELISA.

RESULTS

Compared to the controls subjects, the frequencies of the ACE DD genotype and D allele were overrepresented in patients with CAP (OR = 3.05; [95%CI: 2.14-4.35] for the DD genotype; P < 0.001) and (OR: 1.8; [95%CI: 1.42-2.29]; for the D allele; P < 0.01, respectively). Patients with the DD genotype had significantly higher mean serum ACE levels (45.6 ± 11.4 U/L) compared to those with ID genotype (36.5 ± 8.3 U/L) and II genotype (21.6 ± 5.7 U/L); P < 0.01, respectively.

CONCLUSION

The ACE I/D polymorphism (rs4340) may contribute to the genetic susceptibility of CAP in Egyptian children. The ACE D allele and DD genotype were associated with higher serum ACE levels among studied CAP patients.

Association of the ACE, GSTM1, IL-6, NOS3, and CYP1A1 polymorphisms with susceptibility of mycoplasma pneumoniae pneumonia in Chinese children

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP) and the clinical presentation of mycoplasma pneumoniae pneumonia (MPP) varies widely. Genetic variability affecting the host response may also influence the susceptibility to MPP. Several studies have investigated the association between single nucleotide polymorphism (SNP) of some genes and the risks of CAP; however, the results were inconsistent. Here, we investigated the association of 5 functional genes and the risks of MPP, including ACE (rs4340), GSTM1 (Ins/del), IL-6 (rs1800795), NOS3 (rs1799983), and CYP1A1 (rs2606345) in a total of 715 subjects (415 cases, 300 controls) by using tetra-primer allele-specific polymerase chain reaction (PCR) and Sanger sequencing. The gene-gene interactions were analyzed using the Multifactor Dimensionality Reduction and cumulative genetic risk score approaches. Our results showed that 3 SNPs of ACE rs4340, IL-6 rs1800795, and NOS3 rs1799983 were significantly associated with the risks of MPP, while no differences were observed in genotype frequencies of GSTM1 (Ins/del) and CYP1A1 rs2606345 between both groups. The combinations of ACE rs4340D/NOS3 rs1799983T/CYP1A1 rs2606345G and ACE rs4340D/NOS3 rs1799983T contribute to the genetic susceptibility of MPP in Chinese children.

Genetic Association Between CD143 rs4340 Polymorphism and Pneumonia risk: A Meta Analysis

rs4340 polymorphism at intron 16 of the angiotensin-converting enzyme (CD143) gene was reported to repress cough reflex by reducing bradykinin and substance P levels, thus increasing the likelihood to develop pneumonia. There have been different reports regarding the correlation of CD143 rs4340 genotypes with pneumonia risk, which prompted us to perform a meta-analysis to determine the elusive association.We combined multiple keywords to identify the studies addressing the association between CD143 rs4340 genotypes and pneumonia risk covered in the EMBASE, Google Scholar, PubMed, and CNKI databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the risk of pneumonia. The fixed-effects model (FEM) was used.A total of 10 studies were analyzed in this quantitative analysis. We found a strong association between rs4340 single nucleotide polymorphism (SNP) and pneumonia risk using the recessive model (FEM: OR 1.33, 95% CI 1.13-1.57). A significantly increased risk was also indicated under the recessive model in Asian populations (FEM: OR 1.57, 95% CI 1.19-2.07), community-acquired pneumonia (CAP) (FEM: OR 1.31, 95% CI 1.08-1.60), and nosocomial pneumonia (NP) (FEM: OR 1.52, 95% CI 1.06-2.19).Our meta-analysis demonstrates that CD143 rs4340 polymorphism may represent a risk factor for pneumonia.

Increased risk of pneumonia associated with angiotensin-converting enzyme (CD143) rs4340 polymorphism

The study aims to investigate the genetic association between rs4340 polymorphism at intron 16 of the angiotensin-converting enzyme (CD143) gene and pneumonia predisposition. Electronic database of PubMed, Embase, and CNKI (China National Knowledge Infrastructure) was searched for the studies addressing the association between CD143 rs4340 genotypes and pneumonia risk. The odds ratio (OR) with its 95 % confidence interval (CI) was employed to estimate the association. In total, ten case-control studies, including 1239 pneumonia cases and 2400 healthy controls, met the inclusion criteria. Our results showed a significant association between rs4340 SNP and pneumonia risk using the recessive model (OR 1.43, 95 % CI 1.20-1.70). A significantly increased risk was also indicated under the recessive model in Asian populations (OR 1.63, 95 % CI 1.16-2.30), Caucasian populations (OR 1.34, 95 % CI 1.09-1.65), community-acquired pneumonia (OR 1.42, 95 % CI 1.16-1.75) rather than nosocomial pneumonia (OR 1.47, 95 % CI 0.97-2.23). However, further studies with gene-gene and gene-environmental interactions should be considered to confirm this association.

Sources of heterogeneity in case-control studies on associations between statins, ACE-inhibitors, and proton pump inhibitors and risk of pneumonia

The heterogeneity in case-control studies on the associations between community-acquired pneumonia (CAP) and ACE-inhibitors (ACEi), statins, and proton pump inhibitors (PPI) hampers translation to clinical practice. Our objective is to explore sources of this heterogeneity by applying a common protocol in different data settings. We conducted ten case-control studies using data from five different health care databases. Databases varied on type of patients (hospitalised vs. GP), level of case validity, and mode of exposure ascertainment (prescription or dispensing based). Identified CAP patients and controls were matched on age, gender, and calendar year. Conditional logistic regression was used to calculate odds ratios (OR) for the associations between the drugs of interest and CAP. Associations were adjusted by a common set of potential confounders. Data of 38,742 cases and 118,019 controls were studied. Comparable patterns of variation between case-control studies were observed for ACEi, statins and PPI use and pneumonia risk with adjusted ORs varying from 1.04 to 1.49, 0.82 to 1.50 and 1.16 to 2.71, respectively. Overall, higher ORs were found for hospitalised CAP patients matched to population controls versus GP CAP patients matched to population controls. Prevalence of drug exposure was higher in dispensing data versus prescription data. We show that case-control selection and methods of exposure ascertainment induce bias that cannot be adjusted for and to a considerable extent explain the heterogeneity in results obtained in case-control studies on statins, ACEi and PPIs and CAP. The common protocol approach helps to better understand sources of variation in observational studies.

Angiotensin-converting enzyme I/D polymorphism is associated with pneumonia risk: a meta-analysis

BACKGROUND

Previous studies examined the association between angiotensin-converting enzyme (ACE) I/D polymorphism and pneumonia, but their results were inconsistent. Thus, a meta-analysis was performed to clarify the effect of ACE I/D polymorphism on pneumonia risk and pneumonia-related mortality.

METHODS

The PubMed, Embase, and Chinese National Knowledge Infrastructure (CNKI) databases were searched for relevant studies published up to 27 April 2013. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Pooled analysis of 12 case-control studies (1431 cases and 3600 controls) showed that there was a significant association between ACE I/D polymorphism and pneumonia risk in a recessive genetic model (OR = 1.53, 95% CI 1.30-1.80, p < 0.00001). No significant association between ACE I/D polymorphism and mortality was observed (OR = 2.68, 95% CI 0.80-8.90, p = 0.11).

CONCLUSIONS

Our meta-analysis confirmed that ACE I/D polymorphism was associated with pneumonia risk. However, ACE I/D polymorphism was not associated with pneumonia mortality.

CYP1A1, GCLC, AGT, AGTR1 gene-gene interactions in community-acquired pneumonia pulmonary complications

This study was conducted to establish the possible contribution of functional gene polymorphisms in detoxification/oxidative stress and vascular remodeling pathways to community-acquired pneumonia (CAP) susceptibility in the case-control study (350 CAP patients, 432 control subjects) and to predisposition to the development of CAP complications in the prospective study. All subjects were genotyped for 16 polymorphic variants in the 14 genes of xenobiotics detoxification CYP1A1, AhR, GSTM1, GSTT1, ABCB1, redox-status SOD2, CAT, GCLC, and vascular homeostasis ACE, AGT, AGTR1, NOS3, MTHFR, VEGFα. Risk of pulmonary complications (PC) in the single locus analysis was associated with CYP1A1, GCLC and AGTR1 genes. Extra PC (toxic shock syndrome and myocarditis) were not associated with these genes. We evaluated gene-gene interactions using multi-factor dimensionality reduction, and cumulative gene risk score approaches. The final model which included >5 risk alleles in the CYP1A1 (rs2606345, rs4646903, rs1048943), GCLC, AGT, and AGTR1 genes was associated with pleuritis, empyema, acute respiratory distress syndrome, all PC and acute respiratory failure (ARF). We considered CYP1A1, GCLC, AGT, AGTR1 gene set using Set Distiller mode implemented in GeneDecks for discovering gene-set relations via the degree of sharing descriptors within a given gene set. N-acetylcysteine and oxygen were defined by Set Distiller as the best descriptors for the gene set associated in the present study with PC and ARF. Results of the study are in line with literature data and suggest that genetically determined oxidative stress exacerbation may contribute to the progression of lung inflammation.

Functional polymorphisms in the CYP1A1, ACE, and IL-6 genes contribute to susceptibility to community-acquired and nosocomial pneumonia

OBJECTIVES

To establish the contribution of genetic host factors to the risk of community-acquired pneumonia (CAP) and nosocomial pneumonia (NP) in the population of the Russian Federation.

METHODS

A total of 796 subjects (CAP: 334 patients, 134 controls; NP: 216 critically ill patients with NP, 105 critically ill patients without NP) were included in two case-control studies. We analyzed 13 polymorphisms in 11 genes (IL-6, TNF-α, MBL2, CCR5, NOS3, CYP1A1 (three sites), GSTM1, GSTT1, ABCB1, ACE, and MTHFR) using a tetra-primer allele-specific PCR method.

RESULTS

Individual single nucleotide polymorphism (SNP) analysis revealed a strong association between CYP1A1 rs2606345 and CAP (p=3.9 × 10(-5), odds ratio (OR) 0.42, 95% confidence interval (CI) 0.27-0.63). Three genes (CYP1A1, ACE, and IL-6) were identified that account for part of the increase in vulnerability to both diseases, CAP and NP. The carriage of three predisposing genotypes versus protective genotypes increased the CAP risk (p=0.001, OR 7.01, 95% CI 1.99-24.70) and NP risk (p=0.028, OR 4.34, 95% CI 1.15-16.45).

CONCLUSIONS

Genetic predisposition to CAP and NP is attributed to the cumulative contribution of polymorphisms at the CYP1A1, IL-6, and ACE genes, independently of age, gender, causative pathogen, and the use of mechanical ventilation, in patients in the Russian Federation.

Acute pneumonia and the cardiovascular system

Although traditionally regarded as a disease confined to the lungs, acute pneumonia has important effects on the cardiovascular system at all severities of infection. Pneumonia tends to affect individuals who are also at high cardiovascular risk. Results of recent studies show that about a quarter of adults admitted to hospital with pneumonia develop a major acute cardiac complication during their hospital stay, which is associated with a 60% increase in short-term mortality. These findings suggest that outcomes of patients with pneumonia can be improved by prevention of the development and progression of associated cardiac complications. Before this hypothesis can be tested, however, an adequate mechanistic understanding of the cardiovascular changes that occur during pneumonia, and their role in the trigger of various cardiac complications, is needed. In this Review, we summarise knowledge about the burden of cardiac complications in adults with acute pneumonia, the cardiovascular response to this infection, the potential effects of commonly used cardiovascular and anti-infective drugs on these associations, and possible directions for future research.

Host genetic risk factors for community-acquired pneumonia

This study was conducted to establish the contribution of genetic host factors in the susceptibility to community acquired pneumonia (CAP) in the Russian population. Patients with CAP (n=334), volunteers without a previous history of CAP, constantly exposed to infectious agents, control A group (n=141) and a second control group B consisted of healthy persons (n=314) were included in the study. All subjects were genotyped for 13 polymorphic variants in the genes of xenobiotics detoxification CYP1A1 (rs2606345, rs4646903, and rs1048943), GSTM1 (Ins/del), GSTT1 (Ins/del), ABCB1 rs1045642); immune and inflammation response IL-6 (rs1800795), TNF-a (rs1800629), MBL2 (rs7096206), CCR5 (rs333), NOS3 (rs1799983), angiotensin-converting enzyme ACE (rs4340), and occlusive vascular disease/hyperhomocysteinemia MTHFR (rs1801133). Seven polymorphic variants in genes CYP1A1, GSTM1, ABCB1, NOS3, IL6, CCR5 and ACE were associated with CAP. For two genes CYP1A1 and GSTM1 associations remained significant after correction for multiple comparisons. Multiple analysis by the number of all risk genotypes showed a highly significant association with CAP (P=2.4×10(-7), OR=3.03, 95% CI 1.98-4.64) with the threshold for three risk genotypes. Using the ROC-analysis, the AUC value for multi-locus model was estimated as 68.38.

Risk of pneumonia associated with use of angiotensin converting enzyme inhibitors and angiotensin receptor blockers: systematic review and meta-analysis

OBJECTIVE

To systematically review longitudinal studies evaluating use of angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) and risk of pneumonia.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline through PubMed, Web of Science with conference proceedings (inception to June 2011), and US Food and Drug Administration website (June 2011). Systematic reviews and references of retrieved articles were also searched.

STUDY SELECTION

Two reviewers independently selected randomised controlled trials and cohort and case-control studies evaluating the use of ACE inhibitors or ARBs and risk of pneumonia and retrieved characteristics of the studies and data estimates.

DATA SYNTHESIS

The primary outcome was incidence of pneumonia and the secondary outcome was pneumonia related mortality. Subgroup analyses were carried according to baseline morbidities (stroke, heart failure, and chronic kidney disease) and patients' characteristics (Asian and non-Asian). Pooled estimates of odds ratios and 95% confidence intervals were derived by random effects meta-analysis. Adjusted frequentist indirect comparisons between ACE inhibitors and ARBs were estimated and combined with direct evidence whenever available. Heterogeneity was assessed using the I(2) test.

RESULTS

37 eligible studies were included. ACE inhibitors were associated with a significantly reduced risk of pneumonia compared with control treatment (19 studies: odds ratio 0.66, 95% confidence interval 0.55 to 0.80; I(2) = 79%) and ARBs (combined direct and indirect odds ratio estimate 0.69, 0.56 to 0.85). In patients with stroke, the risk of pneumonia was also lower in those treated with ACE inhibitors compared with control treatment (odds ratio 0.46, 0.34 to 0.62) and ARBs (0.42, 0.22 to 0.80). ACE inhibitors were associated with a significantly reduced risk of pneumonia among Asian patients (0.43, 0.34 to 0.54) compared with non-Asian patients (0.82, 0.67 to 1.00; P<0.001). Compared with control treatments, both ACE inhibitors (seven studies: odds ratio 0.73, 0.58 to 0.92; I(2)=51%) and ARBs (one randomised controlled trial: 0.63, 0.40 to 1.00) were associated with a decrease in pneumonia related mortality, without differences between interventions.

CONCLUSIONS

The best evidence available points towards a putative protective role of ACE inhibitors but not ARBs in risk of pneumonia. Patient populations that may benefit most are those with previous stroke and Asian patients. ACE inhibitors were also associated with a decrease in pneumonia related mortality, but the data lacked strength.

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.

Role of angiotensin-converting enzyme gene polymorphism in persistent pulmonary hypertension of the newborn

AIM

To evaluate the association of angiotensin-converting enzyme (ACE) gene polymorphism with risk/severity of persistent pulmonary hypertension of the newborn (PPHN) among at risk infants.

METHODS

Infants ≥ 34 weeks with respiratory distress at birth were recruited. PPHN was diagnosed clinically and by cardiac echocardiogram. Control group consisted of infants with respiratory distress who did not develop PPHN. ACE genotyping (DD, II, DI genotypes) and serum ACE levels were determined.

RESULTS

A total of 120 infants were included (PPHN = 44; control = 76). Frequency of ACE DD genotype was not different between the two groups of infants (25% versus 33%). Among PPHN infants, severity of illness did not differ between genotypes. Mean (SD) serum ACE levels [15 (9) versus 24 (13) versus 29 (14) U/L] were positively associated with the number of D alleles and inversely associated with infants' gestational age (GA) and level of cardiovascular support.

CONCLUSION

Angiotensin-converting enzyme gene polymorphism did not impact the risk or severity of PPHN among infants ≥ 34 weeks GA.