Recombinant human C1 esterase inhibitor (Conestat alfa) for prophylaxis to prevent attacks in adult and adolescent patients with hereditary angioedema

Introduction: Hereditary angioedema (HAE) due to C1 inhibitor (C1-INH) deficiency is a debilitating and potentially lethal disease. Management includes on-demand treatment of angioedema and their prophylaxis. Plasma derived C1-INH is an established treatment for both on demand and prophylaxis of HAE. Conestat alfa is a recombinant form of human C1-INH (rhC1-INH) produced in transgenic rabbits. It has granted drug\u2019s registration as treatment option for acute HAE attacks in adults and adolescents in Europe, America, and other countries. Long-term prophylaxis with rhC1-INH received recent consideration in clinical trials. Areas covered: This review will critically appraise available information about rhC1-INH (conestat alfa) prophylactic treatment in adult and adolescent patients with congenital C1-INH deficiency. Results from a phase II randomized placebo-controlled trial for prophylaxis of severe HAE evidenced positive treatment outcomes for its application, both twice or once weekly. Expert commentary: Phase II clinical studies suggest that rhC1-INH is a viable option for prophylaxis of HAE. Safety and tolerability data are comparable to other available HAE specific drugs, zeroing the possibility for blood-born viral transmission. Sustainability of modern technologies is granting a practically stable and continuous recombinant production process. With other available options, rhC1-INH facilitates tailoring HAE treatment to patients\u2019 needs

Aspects of hereditary angioedema genotyping in the era of NGS: The case of F12 gene = Wybrane aspekty genotypowania wrodzonego obrzȩku naczynioruchowego w erze NGS: Gen F12

Objective. To screen a cohort of patients diagnosed with non-FXII angioedema for carriage of variants of F12 gene. Material and methods. DNA samples from 191 patients suffering from primary angioedema with normal C1-INH, 54 samples from non- -affected family members, and 161 samples from C1-INH-HAE (154 type I, 7 type II) patients were included in the study. The F12 gene was genotyped by targeted NGS (100% coverage of translated regions). Sanger sequencing was performed for the verification of all identified variants and family segregation studies. Results. The pathogenic F12 variant c.983C>A was detected in three patients from two unrelated families initially diagnosed as U-HAE. Six additional mutations were identified, four of which were characterized as benign (c.41T>C, c.418C>G, c.1025C>T, c.530C>T) and two of uncertain significance (c.1530G>C, c.1768T>G). Two synonymous variants (c.756C>T and c.711C>T), the common polymorphism c.619G>C, and the functional polymorphism c.-4T>C were detected in allele frequencies similar to those presented in the ExAC database for the European population. One more not yet reported synonymous variant (c. 1599A>G) was also found. Conclusion. Analyzing the entire translated region of F12 gene is important in order to identify new variants that possibly affect HAE expressivity. Interestingly, genetic analysis of F12 supports not only the diagnosis of FXII-HAE but also the correct exclusion diagnosis of U-HAE

Current and emerging biologics for the treatment of hereditary angioedema

Introduction: Hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) is a rare disease with unpredictable, self-limiting and localized swelling episodes involving the cutaneous and subcutaneous tissues. In the last decade, the spectrum of the possibilities to control the disease has considerably changed with the development of biologic therapies making necessary a careful evaluation of the differences among current and emerging treatments to properly optimize the management of patients. Areas covered: This review serves to summarize the literature regarding the use of biologics for the treatment of C1-INH-HAE. Medications already available on the market and new drugs in different phases of development are addressed. Expert opinion: the advent of biologic therapies dramatically improved the lives of patients with C1-INH-HAE although further improvement is still needed. Whether this is cost/effective will be answered in the next years when we will see if these major advances will benefit the majority of the patients

Aspects of hereditary angioedema genotyping in the era of NGS: The case of F12 gene [Wybrane aspekty genotypowania wrodzonego obrzȩku naczynioruchowego w erze NGS: Gen F12]

Objective. To screen a cohort of patients diagnosed with non-FXII angioedema for carriage of variants of F12 gene. Material and methods. DNA samples from 191 patients suffering from primary angioedema with normal C1-INH, 54 samples from non- -affected family members, and 161 samples from C1-INH-HAE (154 type I, 7 type II) patients were included in the study. The F12 gene was genotyped by targeted NGS (100% coverage of translated regions). Sanger sequencing was performed for the verification of all identified variants and family segregation studies. Results. The pathogenic F12 variant c.983C>A was detected in three patients from two unrelated families initially diagnosed as U-HAE. Six additional mutations were identified, four of which were characterized as benign (c.41T>C, c.418C>G, c.1025C>T, c.530C>T) and two of uncertain significance (c.1530G>C, c.1768T>G). Two synonymous variants (c.756C>T and c.711C>T), the common polymorphism c.619G>C, and the functional polymorphism c.-4T>C were detected in allele frequencies similar to those presented in the ExAC database for the European population. One more not yet reported synonymous variant (c. 1599A>G) was also found. Conclusion. Analyzing the entire translated region of F12 gene is important in order to identify new variants that possibly affect HAE expressivity. Interestingly, genetic analysis of F12 supports not only the diagnosis of FXII-HAE but also the correct exclusion diagnosis of U-HAE. © Alergia Astma Immunologia 2018

A novel deep intronic SERPING1 variant as a cause of hereditary angioedema due to C1-inhibitor deficiency

Background: In about 5% of patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) no mutation in the SERPING1 gene is detected. Methods: C1-INH-HAE cases with no mutation in the coding region of SERPING1 after conventional genotyping were examined for defects in the intronic or untranslated regions of the gene. Using a next-generation sequencing (NGS) platform targeting the entire SERPING1, 14 unrelated C1-INH-HAE patients with no detectable mutations in the coding region of the gene were sequenced. Detected variants with a global minor allele frequency lower than the frequency of C1-INH-HAE (0.002%), were submitted to in silico analysis using ten different bioinformatics tools. Pedigree analysis and examination of their pathogenic effect on the RNA level were performed for filtered in variants. Results: In two unrelated patients, the novel mutation c.-22-155G > T was detected in intron 1 of the SERPING1 gene by the use NGS and confirmed by Sanger sequencing. All bioinformatics tools predicted that the variant causes a deleterious effect on the gene and pedigree analysis showed its co-segregation with the disease. Degradation of the mutated allele was demonstrated by the loss of heterozygosity on the cDNA level. According to the American College of Medical Genetics and Genomics 2015 guidelines the c.-22-155G > T was curated as pathogenic. Conclusions: For the first time, a deep intronic mutation that was detected by NGS in the SERPING1 gene, was proven pathogenic for C1-INH-HAE. Therefore, advanced DNA sequencing methods should be performed in cases of C1-INH-HAE where standard approaches fail to uncover the genetic alteration. © 2020 Japanese Society of Allergolog

Targeted next-generation sequencing for the molecular diagnosis of hereditary angioedema due to C1-inhibitor deficiency

SERPING1 genotyping of subjects suspicious for hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) is important for clinical practice as well as for research reasons. Conventional approaches towards the detection of C1-INH-HAE-associated SERPING1 variants are cumbersome and time-demanding with many pitfalls. To take advantage of the benefits of next-generation sequencing (NGS) technology, we developed and validated a custom NGS platform that, by targeting the entire SERPING1 gene, facilitates genetic testing of C1-INH-HAE patients in clinical practice. In total, 135 different C1-INH-HAE-associated SERPING1 variants, out of the approximately 450 reported, along with 115 negative controls and 95 randomly selected DNA samples from affected family members of C1-INH-HAE index patients, were included in the forward and reverse validation processes of this platform. Our platform's performance, i.e. analytical sensitivity of 98.96%, a false negative rate of 1.05%, analytical specificity 100%, a false positive rate equal to zero, accuracy of 99.35%, and repeatability of 100% recommends its implementation as a first line approach for the genetic testing of C1-INH-HAE patients or as a confirmatory method. A noteworthy advantage of our platform is the concomitant detection of single nucleotide variants and copy number variations throughout the whole length of the SERPING1 gene, moreover providing information about the size and the localization of the latter. During our study, 15 novel C1-INH-HAE-related SERPING1 variants were detected. © 2018 Elsevier B.V

Abstracts From The 3Rd International Severe Asthma Forum (Isaf)

PubMe