A follow-up survey of patients with acquired angioedema due to C1-inhibitor deficiency.

Hereditary angioedema (HAE) is a rare condition, mostly due to genetic deficiency of complement C1 inhibitor (C1-INH). The rarity of HAE impedes extensive data collection and assessment of the impact of certain factors known to affect the course of this disabling and life-threatening disease. Establishing a global registry could assist to overcome such issues and provides valuable patient data from different countries. The HAE Global Registry is a disease-specific registry, with web-based electronic support, where data are provided by physicians and patients through a dedicated application. We collected data between January 1, 2018, and August 31, 2020. Data on 1297 patients from 29 centers in 5 European countries were collected. At least one attack was recorded for 497 patients during the study period. Overall, 1182 patients were diagnosed with HAE type 1 and 115 with type 2. At the time of database lock, 389 patients were taking long-term prophylactic medication, 217 of which were on danazol. Most recorded attacks affected the abdomen, were generally moderate in severity, and occurred in patients who were not on prophylactic treatment (70.6%, 6244/8848). The median duration of attacks was 780 min (IQR 290–1740) in patients on prophylactic medication and 780 min (IQR 300–1920) in patients not on continuous prophylactic medication. In conclusion, the establishment of a registry for C1-INH-HAE allowed collection of a large amount of data that may help to better understand the clinical characteristics of this disease. This information may enhance patient care and guide future therapeutic decisions.

No abstract

No abstract

BackgroundHereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency (C1-INH-HAE) is a rare autosomal dominant disorder, characterized by recurrent, unpredictable edematous symptoms involving subcutaneous, and/or submucosal tissue. C1-INH-HAE may be caused by more than 700 different mutations in the gene encoding C1-INH (SERPING1) that may lead to decreased protein synthesis or to functional deficiency.MethodsConcentrations of C1-INH, C4, C1q, and anti-C1-INH antibodies, as well as functional C1-INH activity were determined in subjects suffering from edematous symptoms and admitted to the Hungarian Angioedema Center of Reference and Excellence. In those patients, who were diagnosed with C1-INH-HAE based on the complement measurements, SERPING1 was screened by bidirectional sequencing following PCR amplification and multiplex ligation-dependent probe amplification. For detecting large deletions, long-range PCRs covering the entire SERPING1 gene by targeting 2–7 kb long regions were applied.ResultsAltogether 197 individuals with C1-INH deficiency belonging to 68 families were identified. By applying Sanger sequencing or copy number determination of SERPING1 exons, 48 different mutations were detected in 66/68 families: 5 large and 15 small insertions/deletions/delins, 16 missense, 6 nonsense, and 6 intronic splice site mutations. Two novel variations (p.Tyr199Ser [c.596A>C] and the duplication of exon 7) were shown to cosegregate with deficient C1-inhibitor level and activity, while two other variations were detected in single patients (c.797_800delinsCTTGGAGCTCAAGAACTTGGAGCT and c.812dup). A series of long PCRs was applied in the remaining 2 families without an identified mutation and a new, 2606 bp long deletion including the last 91 bp of exon 6 (c.939_1029+2515del) was identified in all affected members of one pedigree. In the remaining one family, a deep intronic SERPING1 variation (c.1029+384A>G) was detected by a targeted next-generation sequencing panel as reported previously.ConclusionsSequencing and copy number determination of SERPING1 exons uncover most pathogenic variants in C1-INH-HAE patients, and further methods are worth to be applied in cases with unrevealed genetic background. Since knowledge of the genetic background may support the establishment of the correct and early diagnosis of C1-INH-HAE, identification of causative mutations and reporting data supporting the interpretation on the pathogenicity of these variants is of utmost importance.