Molecular Genetic Screening in Patients With ACE Inhibitor/Angiotensin Receptor Blocker-Induced Angioedema to Explore the Role of Hereditary Angioedema Genes.

Angioedema is a relatively rare but potentially life-threatening adverse reaction to angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs). As with hereditary forms of angioedema (HAE), this adverse reaction is mediated by bradykinin. Research suggests that ACEi/ARB-induced angioedema has a multifactorial etiology. In addition, recent case reports suggest that some ACEi/ARB-induced angioedema patients may carry pathogenic HAE variants. The aim of the present study was to investigate the possible association between ACEi/ARB-induced angioedema and HAE genes via systematic molecular genetic screening in a large cohort of ACEi/ARB-induced angioedema cases. Targeted re-sequencing of five HAE-associated genes (SERPING1, F12, PLG, ANGPT1, and KNG1) was performed in 212 ACEi/ARB-induced angioedema patients recruited in Germany/Austria, Sweden, and Denmark, and in 352 controls from a German cohort. Among patients, none of the identified variants represented a known pathogenic variant for HAE. Moreover, no significant association with ACEi/ARB-induced angioedema was found for any of the identified common [minor allele frequency (MAF) >5%] or rare (MAF < 5%) variants. However, several non-significant trends suggestive of possible protective effects were observed. The lowest p-value for an individual variant was found in PLG (rs4252129, p.R523W, p = 0.057, p.adjust > 0.999, Fisher's exact test). Variant p.R523W was found exclusively in controls and has previously been associated with decreased levels of plasminogen, a precursor of plasmin which is part of a pathway directly involved in bradykinin production. In addition, rare, potentially functional variants (MAF < 5%, Phred-scaled combined annotation dependent depletion score >10) showed a nominally significant enrichment in controls both: 1) across all five genes; and 2) in the F12 gene alone. However, these results did not withstand correction for multiple testing. In conclusion, our results suggest that HAE-associated mutations are, at best, a rare cause of ACEi/ARB-induced angioedema. Furthermore, we were unable to identify a significant association between ACEi/ARB-induced angioedema and other variants in the investigated genes. Further studies with larger sample sizes are warranted to draw more definite conclusions concerning variants with limited effect sizes, including protective variants.

Exome Sequencing Reveals Common and Rare Variants in F5 Associated With ACE Inhibitor and Angiotensin Receptor Blocker-Induced Angioedema.

Angioedema occurring in the head and neck region is a rare and sometimes life-threatening adverse reaction to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). Few studies have investigated the association of common variants with this extreme reaction, but none have explored the combined influence of rare variants yet. Adjudicated cases of ACEI-induced angioedema (ACEI-AE) or ARB-induced angioedema (ARB-AE) and controls were recruited at five different centers. Sequencing of 1,066 samples (408 ACEI-AE, ARB-AE, and 658 controls) was performed using exome-enriched sequence data. A common variant of the F5 gene that causes an increase in blood clotting (rs6025, p.Arg506Gln, also called factor V Leiden), was significantly associated with both ACEI-AE and ARB-AE (odds ratio: 2.85, 95% confidence interval (CI), 1.89-4.25). A burden test analysis of five rare missense variants in F5 was also found to be associated with ACEI-AE or ARB-AE, P = 2.09 × 10-3 . A combined gene risk score of these variants, and the common variants rs6025 and rs6020, showed that individuals carrying at least one variant had 2.21 (95% CI, 1.49-3.27, P = 6.30 × 10-9 ) times the odds of having ACEI-AE or ARB-AE. The increased risk due to the common Leiden allele was confirmed in a genome-wide association study from the United States. A high risk of angioedema was also observed for the rs6020 variant that is the main coagulation defect-causing variant in black African and Asian populations. We found that deleterious missense variants in F5 are associated with an increased risk of ACEI-AE or ARB-AE.

Dipeptidyl Peptidase-4 Inhibitor Induced Angioedema - An Overlooked Adverse Drug Reaction?

INTRODUCTION: Angioedema is a potentially fatal adverse drug reaction of some medications, as swellings of the upper airways can cause death by asphyxiation. Angiotensin converting enzymeinhibitors are widely known to cause angioedema but less is known about the association between dipeptidyl peptidase-4 inhibitors (gliptins) and angioedema. Dipeptidyl peptidase-4 inhibitors are antidiabetic drugs used to improve glycaemic control. They, as a class effect, inadvertently affect the degradation of the vasoactive kinins bradykinin and substance P, both of which can cause angioedema due to vasodilatation and increase in vascular permeability in the capillaries. OBJECTIVE: To assess the risk and pathomechanism of angioedema due to inhibition of dipeptidyl peptidase- 4 inhibitors when used as monotherapy and in combination with angiotensin converting enzymeinhibitors. METHOD: PubMed, Embase, the Cochrane Library, PubMed Central, Web of Science, Google Scholar and clinicaltrials.gov were searched using different combinations of keywords "angioedema", "dipeptidyl peptidase 4", "dipeptidyl peptidase 4 inhibitors", "gliptins", "bradykinin", "substance P" and "angiotensin converting enzyme-inhibitors". Original research papers were preferably used as references and their bibliographies were used to further the search for original research results. RESULTS: Both angiotensin converting enzyme and dipeptidyl peptidase-4 are major enzymes in the degradation pathway of bradykinin and substance P, and when inhibited pharmacologically - especially at the same time - the theoretical risk of angioedema is increased due to accumulation of vasoactive kinins. CONCLUSION: Treatment with dipeptidyl peptidase-4 inhibitors must be carefully considered and monitored especially during concurrent treatment with angiotensin converting enzyme-inhibitors or when treating patients with a known predisposition to angioedema.

Urticaria and Prodromal Symptoms Including Erythema Marginatum in Danish Patients with Hereditary Angioedema.

Erythema marginatum is a characteristic skin rash seen in patients with hereditary angioedema (HAE); however, it can be confused with urticaria, leading to delay in correct diagnosis. The aim of this study was to clarify how often erythema marginatum is misinterpreted as urticaria, potentially leading physicians to refrain from testing for HAE. Few studies have been published on urticaria and prodromal symptoms in HAE, thus the incidence of these parameters were also investigated. A total of 87 patients affiliated to the national HAE Centre were included. Retrospective and prospective data on skin eruptions and prodromal symptoms were collected. Fifty-six percent of 87 patients had a positive history of erythema marginatum. Half of the patients had experienced erythema marginatum being misinterpreted as urticaria. The most prevalent other prodromal symptoms were other skin symptoms, malaise, psychological changes, fatigue and gastrointestinal symptoms. HAE patients with erythema marginatum have a longer diagnostic delay, presumably caused by misinterpretation of the rash as urticaria.

Angiotensin-converting enzyme inhibitor-induced angioedema--a dangerous new epidemic.

Angioedema is a sudden localised and often asymmetric swelling of the skin or mucous membranes caused by transient increased endothelial permeability causing plasma extravasation. In the last decades the incidence of severe angioedema involving the upper airways and even fatal outcome due to asphyxia has increased. This is mainly due to pharmaceuticals such as angiotensin converting enzyme-inhibitors, which are extensively used worldwide. Some aspects of the pathophysiology have been elucidated and the vasoactive molecule bradykinin is shown to be one of the main causative agents. The diagnosis is often delayed and traditional treatment usually ineffective. Complement C1 inhibitor concentrate and bradykinin receptor antagonists, normally used to treat patients with hereditary angioedema, have shown good results when used in patients with bradykinin-mediated angioedema. This review discusses the disease, prognosis and treatment options.