Association of polymorphisms of the renin-angiotensin system and bradykinin B2 receptor with ACE-inhibitor-related cough

Pharmacogenetic markers of development of angioneurotic edema as a secondary side effect to enalapril in patients with essential arterial hypertension

BACKGROUND

Angioneurotic edema is the most dangerous complication in angiotensin-converting enzyme inhibitors (ACEIs) therapy. Based on the current data, the clinical and genetic predictors of angioedema development are still understudied, which demonstrates the relevance of this study.

OBJECTIVE

To reveal the pharmacogenetic predictors of the angioedema as a secondary side effect to enalapril in patients with essential arterial hypertension.

METHODS

The study enrolled 111 subjects randomized into two groups: study group, patients with the angioedema as a secondary side effect to enalapril; and control group, patients without adverse drug reaction. All patients underwent pharmacogenetic testing.

RESULTS

An association between the development of the angioneurotic edema and the genotypes AA rs2306283 of gene SLCO1B1, TT rs4459610 of gene ACE, and CC rs1799722 of gene BDKRB2 in patients was revealed.

CONCLUSION

The findings justify further investigations of the revealed genetic predictors of angioedema with larger-size patient populations.

A randomized trial of genotype-guided perindopril use

OBJECTIVE

Cough caused by angiotensin-converting enzyme inhibitors (ACEIs) limits their clinical application and cardiovascular benefits. This randomized trial investigated whether genotype-guided perindopril use could reduce drug-related cough in 20 to 79-year-old individuals with hypertension.

METHODS

After screening 120 patients and randomization, 68 were assigned to genotyping ( n  = 41) and control ( n  = 27) groups. NELL1 p.Arg382Trp (rs8176786) and intron (rs10766756) genotype information was used to subdivide the genotyping group into high-risk and low-risk subgroups with at least one or no risk alleles for ACEI-related cough, respectively. The high-risk subgroup received candesartan (8 mg/day) for 6 weeks, whereas the low-risk subgroup received perindopril (4 mg/day). The control group, which was not genotyped, received perindopril (4 mg/day). The primary outcome variables were cough and moderate/severe cough; the secondary outcome variable was any adverse event.

RESULTS

During the 6-week period, the risk of cough was lower in the genotyping group than in the control group [five (12.2%) and nine (33.3%) participants, respectively; hazard ratio: 0.25; log-rank P  = 0.017]. The moderate/severe cough risk was also lower in the genotyping group [one (2.4%) and five (18.5%) participants, respectively; hazard ratio: 0.12; log-rank P  = 0.025]. Differences in cough (hazard ratio: 0.56; log-rank P  = 0.32) and moderate/severe cough risk (hazard ratio: 0.26; log-rank P  = 0.19) between the low-risk and control groups were not significant. The risk of total adverse events was similar between any two groups.

CONCLUSION

Cough risk was lower during genotype-guided treatment than during conventional treatment. These results support the utility of NELL1 variant data in clinical decision making to personalize renin-angiotensin system blocker therapy use.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT05535595 (retrospectively registered at September 7, 2022).

Pharmacogenetic predictors of development of secondary to enalapril dry cough in hypertensive patients

OBJECTIVES

Development of the secondary to ACEI cough leads to discontinuation of the drugs of this group. Assessing the safety of the ACEIs with further development of customized approaches for their administration is a major scientific and practical problem. The objective of this study was to assess the association of the genetic markers with the development of the adverse drug reaction in the form of secondary to enalapril dry cough in the patients with essential arterial hypertension.

METHODS

Study involved 113 patients with the secondary to enalapril cough and 104 patients without development of the secondary to enalapril adverse drug reaction.

RESULTS

The patients carriers of the genotype AA rs2306283 of gene SLCO1B1 had 2-fold higher odds of developing the dry cough than those with the genotypes AG and GG (ОR=2.01, 95%CI=1.10-3.66, р=0.023). Similarly, the patients heterozygous for rs8176746 of gene АВО had 2.3-fold higher odds of developing the ADR in the form of dry cough than the carriers of the genotypes GG and TT (ОR=2.30, 95%CI=1.24-4.29, р=0.008).

CONCLUSIONS

Statistically significant association between the development of the ADR in the form of secondary to enalapril dry cough and polymorphisms rs2306283 of gene SLCO1B1 and rs8176746 of gene ABO was revealed.

Interactions between diabetic and hypertensive drugs: a pharmacogenetics approach

Diabetes is known to increase susceptibility to hypertension due to increase in inflammation, oxidative stress, and endothelial dysfunction, leading to vascular stiffness. The polytherapy might lead to several drug-drug interactions (DDIs), which cause certain life-threatening complications such as diabetic nephropathy and hypoglycaemia. So, in this review we focused on drug-drug interactions and impact of genetic factors on drug responses for better disease management. Drug-drug interactions (DDIs) may act either synergistically or antagonistically. For instance, a combination of metformin with angiotensin II receptor antagonist or angiotensin-converting enzyme inhibitors (ACEIs) synergistically improves glucose absorption, whereas the same hypertensive drug combination with sulphonylurea might cause severe hypoglycaemia sometimes. Thiazolidinediones (TDZs) can cause fluid retention and heart failure when taken alone, but a combination of angiotensin II receptor antagonist with TZDs prevents these side effects. Interindividual genetic variation affects the DDI response. We found two prominent genes, GLUT4 and PPAR-γ, which are common targets for most of the drug. So, all of these findings established a connection between drug-drug interaction and genetics, which might be used for effective disease management.

Pathophysiology of cough with angiotensin-converting enzyme inhibitors: How to explain within-class differences?

Angiotensin converting enzyme inhibitors (ACEi) have consistently demonstrated improved survival and reduced risk of major cardiovascular events, across the spectrum of cardiovascular disease, including hypertension, coronary artery disease, myocardial infarction, and heart failure. The cardioprotective effects of ACEi result from inhibiting the conversion of angiotensin I to angiotensin II, and inhibition of bradykinin degradation. They are generally well tolerated but may cause the onset of a dry cough in some patients. This review presents current evidence on the incidence and mechanisms of cough associated with ACEi use, and then considers how to manage ACEi-related cough in clinical practice. The incidence of ACEi-induced cough in the published literature varies widely due to heterogeneity in the source data and lack of adequate controls. Incidence also varies among individual ACEi with agents such as perindopril, which has a high tissue ACE affinity, associated with a lower rate of cough. Evidence from real-world studies shows that the incidence of ACEi-associated cough is lower than rates reported in clinical trials. Patients who experience any dry cough are often switched to angiotensin- receptor blockers or other classes of antihypertensive drugs, regardless of cough severity. To avoid inappropriate discontinuation of ACEi in clinical practice, an alternative approach in patients with persistent cough is to perform a challenge/re-challenge to determine if re-introduction of ACEi is associated with recurrence of symptoms. Incidence of cough should not be considered a class effect for ACEi, and the patient may benefit by a switch from one ACEi to another. Every effort should be made to enable patients to continue ACEi therapy to reduce adverse cardiovascular outcomes and improve survival.

Gene Polymorphism and Total Genetic Score in Martial Arts Athletes with Different Athletic Qualifications

The personalized approach in sports genetics implies considering the allelic variants of genes in polymorphic loci when adjusting the training process of athletes. The personalized approach is used both in sports genetics and in medicine to identify the influence of genotype on the manifestations of human physical qualities that allow to achieve high sports results or to assess the impact of genotype on the development and course of diseases. The impact of genes of the renin-angiotensin and kinin-bradykinin systems in the development of cardiovascular disease in athletes has not been defined. This study aims to determine the polymorphisms of four genes (ACE, BDKRB2, PPARGC1A and NOS3) and the total genetic score to reveal the predisposition to the formation of physical qualities in martial arts athletes with different athletic abilities. The products of these four genes are involved in the control of blood pressure. The allelic variants of these genes are associated with the development of the physical quality "endurance" and have an indirect influence on the formation of speed and power qualities. The total genetic score (TGS: from 0 to 100 arbitrary units) was calculated from the genotype score in each polymorphism. The athletes were divided into Group I with high and Group II with low qualifications depending on their sports success. Single nucleotide polymorphisms (SNPs) are identified through restriction endonucleases cleavage for PCR amplicons for discriminating between alleles of the target genes ACE (rs4646994), BDKRB2 (rs5810761), PPARGC1A (rs8192673) and NOS3 (rs1799983). Significant differences between the allelic variants of target genes and athletic ability were found between Group I and Group II for genotype G/G of NOS3 gene and genotypes Gly/Gly and Gly/Ser of PPARGC1A gene. The data obtained confirm that athletes with unfavourable genotypes are excluded in the screening phase because their endurance is not fully developed to the required level in martial arts. Martial arts athletes with the highest TGS have the highest skill level. Polymorphic loci of four genes whose products are involved in blood pressure control (ACE, BDKRB2, NOS3 and PPARGC1A) can be used in martial arts not only to determine predisposition to cardiovascular disease but also to predispose to the development of speed and power qualities and endurance. The total genetic score can serve as a tool for predicting athletic success.

Overcoming Cough and Angioedema: Advocating for the Use of ARBs Over ACE Inhibitors

Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors have comparable efficacy, but ARBs have a preferential safety profile with particular regard to cough and angioedema. Although guidelines have historically advocated for ACE inhibitor use before ARBs simply because of earlier market entry, data accumulation, and generic availability, updated verbiage advises an "ACE inhibitor or ARB" recommendation, as opposed to the classic "ACE inhibitor then ARB" approach. Despite these updates, clinical inertia in favor of ACE inhibitor use before ARBs overwhelmingly remains. Prescribers and educators should consider an "ARBs only" mentality, especially in high angioedema-risk groups such as black patients.

Drug-Induced Cough

Since the recognition of angiotensin-converting enzyme inhibitors (ACEIs)-induced cough, drug has been considered as a potential cause of chronic cough. This review presents recent knowledge on drug-induced coughs in patients with chronic cough. The focus is placed on ACEIs, for which there are a multitude of studies documenting their associations with cough. Additional drugs are discussed for which there are reports of cough as a side effect of treatment, and the potential mechanisms of these effects are discussed.

Angiotensin converting enzyme: A review on expression profile and its association with human disorders with special focus on SARS-CoV-2 infection

Angiotensin-converting enzyme (ACE) and its homologue, ACE2, have been mostly associated with hypertensive disorder. However, recent pandemia of SARS-CoV-2 has put these proteins at the center of attention, as this virus has been shown to exploit ACE2 protein to enter cells. Clear difference in the response of affected patients to this virus has urged researchers to find the molecular basis and pathophysiology of the cell response to this virus. Different levels of expression and function of ACE proteins, underlying disorders, consumption of certain medications and the existence of certain genomic variants within ACE genes are possible explanations for the observed difference in the response of individuals to the SARS-CoV-2 infection. In the current review, we discuss the putative mechanisms for this observation.

PNPT1 and PCGF3 variants associated with angiotensin-converting enzyme inhibitor-induced cough: a nested case–control genome-wide study

Aim: We aimed to identify genetic variants associated with ACE inhibitor (ACEI)-induced cough. Materials & methods: A nested case–control study was performed among hypertensive Chinese patients receiving enalapril-only therapy. Whole-exome sequencing and genome-wide association analysis were performed. Results: We identified that PNPT1 rs13015243 (odds ratio [OR]: 0.47; 95% CI: 0.34–0.66; p = 7.45 × 10-6), PNPT1 rs13009649 (OR: 0.48; 95% CI: 0.35–0.67; p = 9.96 × 10-6) and PCGF3 rs1044147 (OR: 2.67; 95% CI: 1.71–4.17; p = 9.91 × 10-6) were significantly associated with ACEI-induced cough. Nearly genome-wide significant associations in previously reported candidate risk genes CLASP1, ACE, CES1, CPN1, XPNPEP1, PDE11A or SLC38A were detected in our dataset. Conclusion: Our results suggest that ACEI-induced cough is associated with noncoding SNPs of PNPT1 and PCGF3, all of which are independent of the bradykinin pathway.

Study registration: NCT03259399.

Nonmetastatic renal cell carcinoma presenting with persistent cough: Case report with literature review

Renal cell carcinomas (RCC), constitute 80– 85% of primary renal neoplasms. The classic triad of RCC (flank pain, hematuria, and a palpable abdominal renal mass) occurs in approximately 9% of patients; it strongly suggests locally advanced disease. RCC may also be associated with a number of paraneoplastic syndromes. These are typically due to ectopic production of various hormones. We present a 69-year-old male patient previously healthy presented to the emergency department with recurrent persistent cough. A non-metastatic RCC was incidentally discovered. Eventually, he underwent left radical nephrectomy. One year has passed with no cough. This is a rare and unusual presentation of RCC that falls under the category of paraneoplastic syndrome with review of similar reported cases and summary of all paraneoplastic syndromes associated with RCC in literature.

Association between genetic polymorphisms and angiotensin-converting enzyme inhibitor-induced cough: a systematic review and meta-analysis

Aim: Genetic polymorphisms may influence the incidence of angiotensin-converting enzyme (ACE) inhibitor-induced cough. This study aims to investigate this association. Methods: Ten electronic databases and PharmGKB were systematically searched. Pooled odds ratio values and their 95% CI were used to assess the association, using the random-effects model. Results: A total of 26 studies were included in the review, 17 of them were included from two separated meta-analysis (ACE I/D or BDKRB2-58T/C). Significant association was found between ACE I/D I carriers (ACE gene insertion) and ACE inhibitor-induced cough, showing racial and age differences. Conclusion: This study demonstrated that ACE I/D but not BDKRB2-58T/C polymorphism could be a predictor for the risk of ACE inhibitor-induced cough, especially in east Asians and the aged.

Angiotensin-Converting Enzyme Inhibitors Induce Cough

Angiotensin-converting enzyme inhibitors (ACE-I) are widely used in diseases, such as hypertension, congestive heart failure, and myocardial infarction. Although these drugs are well tolerated, one out of five patients discontinues ACE-I due to drug side effects, mainly chronic cough. However, the pathogenesis of ACE-I-induced cough remains controversial and requires further study. In this review, the mechanisms that are suggested in ACE-I-induced cough pathophysiology will be discussed in detail in light of the current literature.

An Extensive Study of the Functional Polymorphisms of Kinin-Kallikrein System in Rheumatoid Arthritis Susceptibility

Objectives

This study aims to examine the following functional polymorphisms in rheumatoid arthritis (RA) susceptibility: (i) the 587C>T of kininogen gene, (ii) the 287 bp Alu repeat insertion of angiotensin converting enzyme gene, (iii) the 9 bp insertion of bradykinin receptor 2 gene, (iv) the -58T>C of bradykinin receptor 2 gene, and (v) the -699G>C of bradykinin receptor 1 gene.

Patients and methods

The study included 136 RA patients (27 males; 109 females; mean age 60.8 years; range 39 to 75 years) and 149 ethnic matching controls (30 males, 119 females; mean age 56.2 years; range 35 to 78 years). Polymerase chain reaction coupled with restriction assay was performed for 587C>T, -58T>C, and -699G>C.

Results

Rheumatoid arthritis patients and controls carried the wild type allele of 587C>T; therefore, produced the high molecular weight kininogen. No significant difference was observed in genotype or allele distribution of the studied functional polymorphisms between RA patients and controls.

Conclusion

Kinin-kallikrein system related genes might not be major RA susceptibility loci.

Cough and ACE Inhibitors: The Truth Beyond Placebo

Angiotensin converting enzyme (ACE) inhibitors are extensively used for the prevention and treatment of cardiovascular diseases with a wide range of clinical recommendations. The use of ACE inhibitors can cause the onset of a dry cough, whose prevalence has probably been overestimated because of the lack of adequate control. A correct interpretation of available data requires a careful evaluation of placebo-controlled studies to definitely assess the rate of the most frequent adverse event of ACE inhibition.

Meta-analysis of genome-wide association studies on the intolerance of angiotensin-converting enzyme inhibitors

OBJECTIVES

To identify single nucleotide polymorphisms (SNPs) associated with switching from an angiotensin-converting enzyme (ACE)-inhibitor to an angiotensin receptor blocker.

METHODS

Two cohorts of patients starting ACE-inhibitors were identified within the Rotterdam Study in the Netherlands and the Genetics of Diabetes Audit and Research in Tayside Scotland study in Scotland. Cases were intolerant patients who switched from an ACE-inhibitor to an angiotensin receptor blocker and controls were individuals who used ACE-inhibitors continuously for at least 2 years and did not switch. Genome-wide association study (GWAS) using an additive model was run in these sets and the results were meta-analysed using Genome-Wide Association Meta Analysis software.

RESULTS

A total of 972 cases out of 5161 ACE-inhibitor starters were identified. Eight SNPs within four genes reached the genome-wide association study significance level (P<5×10) in the meta-analysis [RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), γ-aminobutyric acid receptor subunit γ-2, sarcoma (Src) homology 2 (SH2) B adaptor protein 1 and membrane bound O-acyltransferase domain containing 1]. The strongest associated SNP was located in an intron of RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), which contains an RNA binding protein [rs2061538: minor allele frequency=0.16, odds ratio=1.52 (95% confidence interval: 1.32-1.76), P=6.2×10].

CONCLUSION

These results indicate that genetic variation in the above-mentioned genes may increase the risk of ACE-inhibitor-induced adverse reactions.

Genetic variants associated with angiotensin-converting enzyme inhibitor-induced cough: a genome-wide association study in a Swedish population

Aim: We conducted a genome-wide association study on angiotensin-converting enzyme inhibitor-induced cough and used our dataset to replicate candidate genes identified in previous studies. Patients & methods: A total of 124 patients and 1345 treated controls were genotyped using Illumina arrays. The genome-wide significance level was set to p < 5 × 10-8. Results: We identified nearly genome-wide significant associations in CLASP1, PDE11A, KCNMB2, TGFA, SLC38A6 and MMP16. The strongest association was with rs62151109 in CLASP1 (odds ratio: 3.97; p = 9.44 × 10-8). All top hits except two were located in intronic or noncoding DNA regions. None of the candidate genes were significantly associated in our study. Conclusion: Angiotensin-converting enzyme inhibitor-induced cough is potentially associated with genes that are independent of bradykinin pathways.

Unraveling the Pivotal Role of Bradykinin in ACE Inhibitor Activity

Historically, the first described effect of an angiotensin converting enzyme (ACE) inhibitor was an increased activity of bradykinin, one of the substrates of ACE. However, in the subsequent years, molecular models describing the mechanism of action of ACE inhibitors in decreasing blood pressure and cardiovascular risk have focused mostly on the renin-angiotensin system. Nonetheless, over the last 20 years, the importance of bradykinin in regulating vasodilation, natriuresis, oxidative stress, fibrinolysis, inflammation, and apoptosis has become clearer. The affinity of ACE appears to be higher for bradykinin than for angiotensin I, thereby suggesting that ACE inhibitors may be more effective inhibitors of bradykinin degradation than of angiotensin II production. Data describing the effect of ACE inhibition on bradykinin signaling support the hypothesis that the most cardioprotective benefits attributed to ACE inhibition may be due to increased bradykinin signaling rather than to decreased angiotensin II signaling, especially when high dosages of ACE inhibitors are considered. In particular, modulation of bradykinin in the endothelium appears to be a major target of ACE inhibition. These new mechanistic concepts may lead to further development of strategies enhancing the bradykinin signaling.

A Physiologic Approach to the Pharmacogenomics of Hypertension

Hypertension is a multifactorial condition with diverse physiological systems contributing to its pathogenesis. Individuals exhibit significant variation in their response to antihypertensive agents. Traditional markers, such as age, gender, diet, plasma renin level, and ethnicity, aid in drug selection. However, this review explores the contribution of genetics to facilitate antihypertensive agent selection and predict treatment efficacy. The findings, reproducibility, and limitations of published studies are examined, with emphasis placed on candidate genetic variants affecting drug metabolism, the renin-angiotensin system, adrenergic signalling, and renal sodium reabsorption. Single-nucleotide polymorphisms identified and replicated in unbiased genome-wide association studies of hypertension treatment are reviewed to illustrate the evolving understanding of the disease's complex and polygenic pathophysiology. Implementation efforts at academic centers seek to overcome barriers to the broad adoption of pharmacogenomics in the treatment of hypertension. The level of evidence required to support the implementation of pharmacogenomics in clinical practice is considered.

A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough

The most common side effect of angiotensin-converting enzyme inhibitor (ACEi) drugs is cough. We conducted a genome-wide association study (GWAS) of ACEi-induced cough among 7080 subjects of diverse ancestries in the Electronic Medical Records and Genomics (eMERGE) network. Cases were subjects diagnosed with ACEi-induced cough. Controls were subjects with at least 6 months of ACEi use and no cough. A GWAS (1595 cases and 5485 controls) identified associations on chromosome 4 in an intron of KCNIP4. The strongest association was at rs145489027 (minor allele frequency=0.33, odds ratio (OR)=1.3 (95% confidence interval (CI): 1.2–1.4), P=1.0 × 10⁻⁸). Replication for six single-nucleotide polymorphisms (SNPs) in KCNIP4 was tested in a second eMERGE population (n=926) and in the Genetics of Diabetes Audit and Research in Tayside, Scotland (GoDARTS) cohort (n=4309). Replication was observed at rs7675300 (OR=1.32 (1.01–1.70), P=0.04) in eMERGE and at rs16870989 and rs1495509 (OR=1.15 (1.01–1.30), P=0.03 for both) in GoDARTS. The combined association at rs1495509 was significant (OR=1.23 (1.15–1.32), P=1.9 × 10⁻⁹). These results indicate that SNPs in KCNIP4 may modulate ACEi-induced cough risk.

An update on the pharmacogenetics of treating hypertension

Hypertension is a leading cause of cardiovascular mortality, but only one third of patients achieve blood pressure goals despite antihypertensive therapy. Genetic polymorphisms may partially account for the interindividual variability and abnormal response to antihypertensive drugs. Candidate gene and genome-wide approaches have identified common genetic variants associated with response to antihypertensive drugs. However, there is no currently available pharmacogenetic test to guide hypertension treatment in clinical practice. In this review, we aimed to summarize the recent findings on pharmacogenetics of the most commonly used antihypertensive drugs in clinical practice, including diuretics, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, beta-blockers and calcium channel blockers. Notably, only a small percentage of the genetic variability on response to antihypertensive drugs has been explained, and the vast majority of the genetic variants associated with antihypertensives efficacy and toxicity remains to be identified. Despite some genetic variants with evidence of association with the variable response related to these most commonly used antihypertensive drug classes, further replication is needed to confirm these associations in different populations. Further studies on epigenetics and regulatory pathways involved in the responsiveness to antihypertensive drugs might provide a deeper understanding of the physiology of hypertension, which may favor the identification of new targets for hypertension treatment and genetic predictors of antihypertensive response.

Genetic manipulation and genetic variation of the kallikrein-kinin system: impact on cardiovascular and renal diseases

Genetic manipulation of the kallikrein-kinin system (KKS) in mice, with either gain or loss of function, and study of human genetic variability in KKS components which has been well documented at the phenotypic and genomic level, have allowed recognizing the physiological role of KKS in health and in disease. This role has been especially documented in the cardiovascular system and the kidney. Kinins are produced at slow rate in most organs in resting condition and/or inactivated quickly. Yet the KKS is involved in arterial function and in renal tubular function. In several pathological situations, kinin production increases, kinin receptor synthesis is upregulated, and kinins play an important role, whether beneficial or detrimental, in disease outcome. In the setting of ischemic, diabetic or hemodynamic aggression, kinin release by tissue kallikrein protects against organ damage, through B2 and/or B1 bradykinin receptor activation, depending on organ and disease. This has been well documented for the ischemic or diabetic heart, kidney and skeletal muscle, where KKS activity reduces oxidative stress, limits necrosis or fibrosis and promotes angiogenesis. On the other hand, in some pathological situations where plasma prekallikrein is inappropriately activated, excess kinin release in local or systemic circulation is detrimental, through oedema or hypotension. Putative therapeutic application of these clinical and experimental findings through current pharmacological development is discussed in the chapter.

Pharmacogenetics of ACE inhibitor-induced angioedema and cough: a systematic review and meta-analysis

AIM

Angioedema and cough are the two most important adverse effects of ACE inhibitors (ACEIs). Evidence exists that ACEI-related angioedema/cough is partly genetically determined and several genes have been identified to play a role in the development of ACEI-related adverse effects.

MATERIALS & METHODS

This study was performed in order to evaluate the evidence of these genetic associations and ACEIs' adverse effects. After removing duplicates and critical appraisal, 19 studies were considered to be eligible to review; 14 articles about cough and five articles about angioedema. A separate meta-analysis was performed for the most studied ACE insertion/deletion polymorphism (rs4646994) and its association with cough.

RESULTS & CONCLUSION

One gene region (XPNPEP2) was associated with ACEI-induced angioedema in three studies. In our meta-analysis we did not find a significant association between the ACE insertion/deletion polymorphism and ACEI cough.

Tolerability of angiotensin-receptor blockers in patients with intolerance to angiotensin-converting enzyme inhibitors: a systematic review and meta-analysis

BACKGROUND

Between 5% and 20% of patients treated with angiotensin-converting enzyme inhibitors (ACE inhibitors) develop intolerance. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) can be used as an alternative treatment.

OBJECTIVE

In this study we aimed to evaluate the tolerability of ARBs in patients with intolerance to ACE inhibitors.

DATA SOURCES

The electronic databases PubMed, MEDLINE/EMBASE via Dialog, CENTRAL, and ISI Web of Knowledge were searched.

STUDY SELECTION

Randomized controlled trials (RCTs) evaluating ARBs in patients with intolerance to ACE inhibitors were selected.

DATA SYNTHESIS

Risk ratio (RR) and 95% confidence intervals (CIs) were estimated assuming the random effects method. We found 11 RCTs comparing ARBs with ACE inhibitors, diuretics, or placebo, and one RCT comparing high-dose versus low-dose ARB.

RESULTS

ARBs had fewer cough events versus ACE inhibitors (RR 0.37; 95% CI 0.28, 0.48). ARBs had drug discontinuation (RR 0.99; 95% CI 0.84, 1.17) and cough risk (RR 1.01; 95% CI 0.74, 1.39) rates similar to placebo. Angioedema risk with ARBs was also similar to placebo (RR 1.62; 95% CI 0.17, 15.79). Compared with placebo, hypotension (RR 2.63; 95% CI 1.77, 3.92), renal dysfunction (RR 2.07; 95% CI 1.45, 2.95) and hyperkalemia (RR 3.37; 95% CI 1.60, 7.11) were more frequent with ARBs.

CONCLUSIONS

ACE inhibitor rechallenge should be discouraged in patients with previous intolerance to ACE inhibitors due to a higher risk of cough. ARBs had cough and angioedema incidences similar to placebo. Despite a significantly higher incidence of hypotension, renal dysfunction and hyperkalemia, discontinuation of ARBs was similar to placebo.

Angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism and ACE inhibitor-related cough: a meta-analysis

OBJECTIVE

An insertion/deletion (I/D) variant in the angiotensin-converting enzyme (ACE) gene was associated with ACE inhibitor (ACEI)-related cough in previous studies. However, the results were inconsistent. Our objective was to assess the relationship between the ACE I/D polymorphism and ACEI-related cough by meta-analysis and to summarize all studies that are related to ACE I/D polymorphism and ACEI-cough and make a summary conclusion to provide reference for the researchers who attempt to conduct such a study.

METHODS

Databases including PubMed, EMbase, Cochrane Library, and China National Knowledge Infrastructure, were searched for genetic association studies. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity.

RESULTS

Eleven trials, including 906 cases (ACEI-related cough) and 1,175 controls, were reviewed in the present meta-analysis. The random effects pooled OR was 1.16 (95%CI: 0.78-1.74, p=0.46) in the dominant model and 1.61 (95%CI: 1.18-2.20, p=0.003) in the recessive model. Heterogeneity was found among and within studies. Metaregression indicated that the effect size was positively associated with age and negatively associated with follow-up duration of ACEI treatment. Subgroup analysis revealed a significant association between ACE I/D polymorphism and ACEI-related cough in studies with mean age >60 y, but not in studies with mean age ≤ 60 y. No heterogeneity was found within each mean age subgroup. We also found no association between ACE I/D polymorphism and ACEI-related cough in studies with follow-up>2 mo or in studies in Caucasians. No heterogeneity was detected in these two subgroups.

CONCLUSIONS

Synthesis of the available evidence supports ACE I/D polymorphism as an age-dependent predictor for risk of ACEI-related cough.

Pharmacogenetic predictors of angiotensin-converting enzyme inhibitor-induced cough: the role of ACE, ABO, and BDKRB2 genes

BACKGROUND AND OBJECTIVE

Dry cough is the most common reason for stopping angiotensin-converting enzyme inhibitors (ACEi) therapy. The role of ACE in the metabolism of bradykinin has been proposed as a pathogenic mechanism. This study included a complete analysis of the variability of the genes involved in bradykinin metabolism (ACE and XPNPEP2) and bradykinin receptors (BDKRB2). We included two polymorphisms in the ABO (related to ACE levels); two polymorphisms in the AGTR1, and one polymorphism in the BKRB1 (related to ACEi response).

METHODS

A total of 281 patients who had been treated with ACEi were retrospectively recruited [102 patients were considered as cases (cough) and 179 patients were considered as controls (no cough)], and 56 polymorphisms were tested for association.

RESULTS

We found that genetic polymorphisms in BDKRB2 [rs8016905; P=0.003; odds ratio (OR)=2.21] and ABO (rs495828; P=0.001; OR=2.45) are associated with ACEi-induced cough after correction for multiple testing. The effect of polymorphisms in ABO was sex specific (female patients; P=0.0006; OR=3.26). When we analyzed the subgroup of patients homozygous GG for rs4343, two polymorphisms in the ACE were found to have protective properties (rs4459610 and rs4267385; P=0.005 and 0.004; OR=0.25). We also found a strong interaction between the ABO polymorphisms, rs495828 and rs8176746 (P<0.0001; OR=3.7).

CONCLUSION

These results highlight the importance of genetic determinants of ACE levels as good predictors of the ACEi response, and provide ABO as a good candidate gene for pharmacogenetic studies of ACEi-related cough. Moreover, our results also confirm the importance of bradykinin in the pathogenesis of this adverse effect.

Angiotensin-converting enzyme and bradykinin gene polymorphisms and cough: A meta-analysis

AIM

To evaluate the association between genetic polymorphisms and angiotensin converting enzyme inhibitor (ACEI)-related cough, and the race- or ethnicity-related difference in the prevalence of cough attributed to ACEI therapy.

METHODS

We conducted a search in PubMed, EMBASE, Cinahl, and the Cochrane Database without language limitation. A database of 11 studies on ACEI-related cough, with detailed information regarding ACE I/D or bradykinin B(2) receptor polymorphisms, was created. Eligible studies were synthesized using meta-analysis methods, including cumulative meta-analysis. A subgroup analysis was also performed using ethnicity.

RESULTS

Six studies were included on ACE I/D polymorphism (398 Caucasians, 723 East Asians), and three studies were included on bradykinin B(2) receptor polymorphism (300 East Asians). The distribution of ACE genotypes showed significant differences in the entire population (P = 0.004) and in East Asians (P = 0.005) but not in Caucasians (P = 0.23). Allelic frequencies of ACE showed significant differences in East Asians [odds ratio (OR) = 1.49 (1.11-2.02)]. The meta-analysis with a random effects model showed a significant association between ACE allele I/D and ACEI-related cough [random effects (RE) OR = 1.49 (1.11-2.02), P = 0.009] in East Asians, but not in Caucasians [RE OR = 0.90 (0.60-1.35)]. The allelic frequencies of the bradykinin B(2) receptor gene were significantly different [OR = 2.25 (1.42-3.57)]. The distributions of the T/C genotypes of the bradykinin B(2) receptor gene were significantly different (χ(2) = 8.366, P = 0.015). The meta-analyses revealed that there was a significant association between the bradykinin B(2) receptor allele and ACEI-related cough in East Asians [RE OR = 2.29 (1.42-3.69), P = 0.001].

CONCLUSION

ACE I/D and Bradykinin B(2) receptor polymorphisms contributed to the risk of ACEI-related cough in East Asians, but a negative association between ACE I/D polymorphism and ACEI-related cough was observed in Caucasians.

Potential genetic risk factors in angiotensin-converting enzyme-inhibitor-induced angio-oedema

AIMS

The pathophysiology of angiotensin-converting enzyme inhibitor (ACEi)-induced angio-oedema remains unclear. We have investigated the impact of ACE insertion/deletion (I/D) polymorphism in combination with serum ACE activity as well as the bradykinin B2 receptor 2/3 and c.C181T polymorphisms.

METHODS

We analysed the ACE I/D as well as bradykinin B2 (2/3 and C181T) receptor polymorphisms in 65 patients with documented episodes of ACEi-induced angio-oedema and 65 patients matched for age and sex being under ACEi treatment without history of angio-oedema. Furthermore, we determined serum ACE activity in 47 of the 65 angio-oedema patients 3 months after the angio-oedema attack and compared these values with 51 healthy individuals (control II).

RESULTS

No risk association was identified between ACE I/D (I-allele: 0.42 vs. 0.41, D-allele: 0.58 vs. 0.59; P= 0.095) or bradykinin B2 receptor polymorphisms and the development of angio-oedema during ACEi treatment. We found a trend of lower serum ACE activity in ACE I/I genotypes in comparison with control II (I/I: 28 +/- 4.5 vs. 33 +/- 1.8 U l(-1); ID: 39 +/- 3.3 vs. 41 +/- 1 U l(-1); DD: 56 +/- 6.7 vs. 52 +/- 1.8 U l(-1); P= 0.9).

CONCLUSIONS

Our data suggest that polymorphism of ACE I/D and the bradykinin B2 receptor polymorphisms are not involved in the development of ACEi-induced angio-oedema when considered individually. Further studies should be carried out to clarify whether a combination of these polymorphisms might be a risk factor for ACEi-induced angio-oedema.

Differences between zofenopril and ramipril, two ACE inhibitors, on cough induced by citric acid in guinea pigs: role of bradykinin and PGE2

Dry and persistent cough is one of the commonest side effects experienced by patients treated with angiotensin-converting enzyme (ACE) inhibitors for the therapy of hypertension and congestive heart failure. The present study investigated the effect of zofenopril and ramipril on cough induced by citric acid in guinea pig and the involvement of bradykinin (BK) and prostaglandin E2 (PGE2) in mediating the responses of these drugs. Zofenopril (10 mg/kg) or ramipril (3-10 mg/kg), which is threefold more potent than zofenopril, on a mg basis, in lowering blood pressure, was orally administered daily in drinking water for 2 weeks. At the end of this period, aerosol of citric acid solution (0.1 M) was performed and the number of cough counted for 10 min. The role of the kinin B(2) receptor was also investigated. BK and PGE2 levels in the bronchoalveolar lavage (BAL) fluid were measured after repeated oral treatment with zofenopril or ramipril (10 mg/kg). Ramipril (3-10 mg/kg) increased citric acid-induced cough by 40% and 60%, respectively, as compared to the vehicle control group (15.0 ± 1.8), while zofenopril (10 mg/kg) was without effect. The enhancement of citric acid-induced cough caused by ramipril (10 mg/kg) was reduced by the kinin B(2) receptor antagonist MEN16132 (0.25 mg/kg ip). BK and PGE2 levels in the BAL fluid were increased, in comparison to the control group, after ramipril treatment, while they were unchanged after zofenopril administration. Zofenopril, contrary to ramipril, did not affect either citric acid-induced cough in the guinea pigs or BK and PGE2 production in the airways.

A meta-analysis of the bradykinin B2 receptor gene --58C/T polymorphism with hypertension

BACKGROUND AND OBJECTIVE

Numerous studies have attempted to associate -58C/T polymorphism of bradykinin B2 receptor gene (BDKRB2) with hypertension, whereas results were often irreproducible. We performed a meta-analysis aiming to provide a comprehensive evaluation of this polymorphism and hypertension.

METHODS

Case-control reports published in English were searched totaling four studies with six populations (823 cases and 916 controls). Random-effects model was applied irrespective of between-study heterogeneity, and study quality was assessed in duplicate.

RESULTS

Compared with -58C allele carriers, those with -58T allele had a lower yet nonsignificant risk for hypertension (OR=0.86; 95% CI: 0.68-1.09; P=0.21). Lack of significance persisted after combining those with genotypes -58TC and -58TT together (OR=0.87; 95% CI: 0.67-1.09; P=0.21) or with -58TC and -58CC together (OR=0.75; 95% CI: 0.48-1.18; P=0.22) in association with hypertension. Sensitivity analyses by race indicated that comparison of -58T versus -58C generated a protective effect for hypertension in Asians (OR=0.77; 95% CI: 0.58-1.02; P=0.07) and African-Americans (OR=0.65; 95% CI: 0.43-0.98; P=0.04), but a risk effect in Caucasians (OR=1.22; 95% CI: 0.92-1.61; P=0.17). No publication bias was observed.

CONCLUSIONS

Our results suggested that -58T allele exhibited a protective effect on hypertension in Asians and African-Americans, yet a risk effect in Caucasians.

Angiotensin converting enzyme inhibitor induced angio-oedema: a review of the pathophysiology and risk factors

Angio-oedema (AE) is a known adverse effect of angiotensin converting enzyme inhibitor (ACE-I) therapy. Over the past several decades, evidence of failure to diagnose this important and potentially fatal reaction is commonly found in the literature. Because this reaction is often seen first in the primary care setting, a review was undertaken to analyse and document the keys to both diagnostic criteria as well as to investigate potential risk factors for ACE-I AE occurrence. A general review of published literature was conducted through Medline, EMBASE, and the Cochrane Database, targeting ACE-I-related AE pathomechanism, diagnosis, epidemiology, risk factors, and clinical decision making and treatment. The incidence and severity of AE appears to be on the rise and there is evidence of considerable delay in diagnosis contributing to significant morbidity and mortality for patients. The mechanism of AE due to ACE-I drugs is not fully understood, but some genomic and metabolomic information has been correlated. Additional epidemiologic data and clinical treatment outcome predictors have been evaluated, creating a basis for future work on the development of clinical prediction tools to aid in risk identification and diagnostic differentiation. Accurate recognition of AE by the primary care provider is essential to limit the rising morbidity associated with ACE-I treatment-related AE. Research findings on the phenotypic indicators relevant to this group of patients as well as basic research into the pathomechanism of AE are available, and should be used in the construction of better risk analysis and clinical diagnostic tools for ACE-I AE.

Evaluation of olmesartan medoxomil in the rat monocrotaline model of pulmonary hypertension

It is suggested that angiotensin II is involved in the pathogenesis of pulmonary hypertension and subsequent right ventricular hypertrophy; therefore, an angiotensin AT1 receptor antagonist could be beneficial for the treatment of this disease. We tested the effect of the new AT1 receptor antagonist olmesartan medoxomil on monocrotaline-induced pulmonary hypertension in rats. At 3 weeks after a single subcutaneous injection of monocrotaline (50 mg/kg), the lung/body weight ratio, the right ventricle/(left ventricle plus septum) weight ratio [RV/(LV+S)], and right ventricular systolic pressure were increased, indicating establishment of pulmonary hypertension and right ventricular hypertrophy. Oral administration of olmesartan medoxomil (2 or 5 mg/kg/day for 3 weeks) restored RV/(LV+S) and right ventricular systolic pressure, and a higher dose (5 mg/kg/day) improved the lung/body weight ratio. Pulmonary arteries isolated from monocrotaline-treated rats exhibited an increase in basal tone in the resting state, indicating that they had intrinsic tone. Three weeks of treatment with olmesartan decreased this intrinsic tone. These data suggest that long-term treatment with olmesartan has beneficial effects on monocrotaline-induced pulmonary hypertension and subsequent right ventricular hypertrophy.

Towards triple vasopeptidase inhibitors for the treatment of cardiovascular diseases

Cardiovascular diseases (CDs) are among the most encountered pathologies in western countries; with obesity reaching pandemic proportions, they are soon to become a worldwide problem. High blood pressure is the main risk factor for CDs, and its tight control is an imperative for the treatment of complications such as renal diseases, heart failure, and atherosclerosis. Blood homeostasis and vascular tone are regulated through at least 3 major closely interrelated pathways in which zinc metallopeptidases modulate the concentration of vasoactive mediators. Those extensively studied vasopeptidases were therefore rapidly targeted with specific inhibitors in order to control the levels of vasoconstrictors [angiotensin II (AII) and endothelin-1 (ET-1)] and vasodilators [bradykinin (BK) and atrial natriuretic peptide (ANP)], thereby controlling blood pressure. The first class of inhibitors to be developed were against angiotensin-converting enzyme (ACE), recently followed by dual inhibitors of ACE/neprylisin (NEP), NEP/endothelin-converting enzyme (ECE), and finally triple ACE/NEP/ECE inhibitors. The dual and triple inhibitors are defined as vasopeptidase inhibitors (VPI). In addition to their ability to effectively lower blood pressure in hypertensive patients, drugs targeting these enzymes also displayed antiinflammatory and antifibrotic activities. The major point emerging from recent studies undertaken to improve the management of CDs is that the combined action of different therapeutic strategies (ie, simultaneous modulation of several neurohumoral mediators) shows better results than conservative therapeutic approaches. In this review, we historically present the advances made in the comprehension of the different mechanisms of blood pressure regulation and some of the drugs that arose from this understanding.

Obstinate cough as a sole presenting symptom of non-metastatic renal cell carcinoma

Renal cell carcinoma (RCC) causes many kinds of symptoms such as hypercalcemia, hypertension, polycythemia and fever. Here we describe a rare case of RCC presenting with a persistent cough. After radical nephrectomy, the obstinate cough disappeared. When the tumor recurred locally, the cough also recurred. Furthermore, the cough disappeared completely again after the removal of the recurrent tumor. Although all the clinical findings suggested that the RCC caused the cough, we could not identify a specific humoral substance responsible for the cough.

Tolerability of ramipril 10 mg daily in high-risk cardiovascular patients in Taiwan: experience from Kaohsiung Medical University Chung-Ho Memorial Hospital

The Heart Outcomes Prevention Evaluation (HOPE) study demonstrated that the angiotensin-converting enzyme inhibitor, ramipril, significantly reduces mortality, myocardial infarction and stroke in high-risk cardiovascular patients, beyond the benefits from blood pressure lowering. The tolerability of ramipril 10 mg/day has been an important concern when applying these results. Following the same criteria as the HOPE study, we investigated the adverse effects profile and tolerability of 10 mg ramipril in high-risk patients at our institution. In total, 92 patients with high cardiovascular risk were eligible for this study. Initially, ramipril was prescribed 2.5 mg orally once daily, and then titrated up to 5.0, 7.5, and 10.0 mg/day at 1-month intervals. The target maintenance dose was 10 mg/day. All adverse events were recorded during at least 3 months of follow-up. After 4-6 months of the titration protocol, only 18 patients (25.3%) reached and remained on ramipril 10 mg/day; 11 (15.5%), 22 (30.9%), and 20 patients (28.2%) remained on 2.5, 5.0, and 7.5 mg/day, respectively. Twenty-one patients (22.6%) had at least one adverse event. Twelve patients (13.0%) stopped treatment because of adverse effects. A total of 23 episodes of adverse events were reported, including cough (15.1%), dizziness (6.0%), and hypotension (2.4%). Ramipril was relatively well tolerated in our study population. However, only one-quarter of our patients reached the target maintenance dose of 10 mg/day. Dry cough, dizziness, and hypotension were the major side effects. About 15% of our patients discontinued ramipril treatment, which is comparable with previous reports.

International union of pharmacology. XLV. Classification of the kinin receptor family: from molecular mechanisms to pathophysiological consequences

Kinins are proinflammatory peptides that mediate numerous vascular and pain responses to tissue injury. Two pharmacologically distinct kinin receptor subtypes have been identified and characterized for these peptides, which are named B1 and B2 and belong to the rhodopsin family of G protein-coupled receptors. The B2 receptor mediates the action of bradykinin (BK) and lysyl-bradykinin (Lys-BK), the first set of bioactive kinins formed in response to injury from kininogen precursors through the actions of plasma and tissue kallikreins, whereas the B(1) receptor mediates the action of des-Arg9-BK and Lys-des-Arg9-BK, the second set of bioactive kinins formed through the actions of carboxypeptidases on BK and Lys-BK, respectively. The B2 receptor is ubiquitous and constitutively expressed, whereas the B1 receptor is expressed at a very low level in healthy tissues but induced following injury by various proinflammatory cytokines such as interleukin-1beta. Both receptors act through G alpha(q) to stimulate phospholipase C beta followed by phosphoinositide hydrolysis and intracellular free Ca2+ mobilization and through G alpha(i) to inhibit adenylate cyclase and stimulate the mitogen-activated protein kinase pathways. The use of mice lacking each receptor gene and various specific peptidic and nonpeptidic antagonists have implicated both B1 and B2 receptors as potential therapeutic targets in several pathophysiological events related to inflammation such as pain, sepsis, allergic asthma, rhinitis, and edema, as well as diabetes and cancer. This review is a comprehensive presentation of our current understanding of these receptors in terms of molecular and cell biology, physiology, pharmacology, and involvement in human disease and drug development.

Drug-induced airway diseases

Drug-induced airway disease is a significant problem and must be considered in the differential diagnosis. A history of drug intake with a temporal association should raise the physician's suspicion toward a drug-induced cause. Because most of the conditions are amenable to withdrawal of the offending agent, an early diagnosis is essential. Conditions like obliterative bronchiolitis, are usually irreversible, but timely stoppage of the provoking agent can prevent further progression of the disease. Most of the drug reactions are nonallergic and the physician and the patient should be aware of this fact. In view of the constantly-evolving therapies, an active policy to identify and report adverse effects is essential to develop management strategies and treatment recommendations.