To date, eosinophil involvement in HAE has not been systematically investigated, this study aimed to validate clinical observations and explore a potential link between bradykinin signaling and eosinophilic inflammation.<h4>Methods</h4>We retrospectively analyzed data from 48 patients with confirmed HAE (32 HAE type I/II, 16 HAE with normal C1-INH) and 1,880 control patients treated at a tertiary university allergy and angioedema referral center. This evidence concerns the gene SERPING1 and hereditary angioedema.