Guilarte, MarSala-Cunill, AnnaLuisa Baeza, MariaCabanas, RosarioDolores Hernandez, MariaIbanez, EthelHernando de Larramendi, CarlosLleonart, RamonLobera, TeofiloMarques, Luisde San Pedro, Blanca SaenzBotha, JacoAndresen, IrmgardCaballero, TeresaIOS Study Grp2025-01-072025-01-072021-12-291710-1492https://hdl.handle.net/10668/26598Background The Icatibant Outcome Survey (IOS) is an international registry monitoring the use of icatibant, a bradykinin B-2 receptor antagonist indicated for the acute treatment of hereditary angioedema (HAE) attacks. Our goal was to assess disease characteristics and icatibant treatment outcomes in patients with HAE due to C1 inhibitor deficiency (HAE type 1 or 2 (HAE-1/2)) from Spain relative to other countries participating in IOS. Methods Descriptive retrospective analyses of data are reported from 10 centers in Spain vs 51 centers in 12 other participating countries (July 2009 to January 2019). Results No meaningful differences were identified between patients in Spain (n = 119) and patients across other countries (n = 907) regarding median age at symptom onset (15.0 vs 12.0 years) or diagnosis (22.3 vs 20.5 years). Overall HAE attack rates (total attacks/total years of follow-up) were 2.66 in Spain and 1.46 across other countries. Patients in Spain reported fewer severe/very severe HAE attacks before treatment (41.0% vs 45.9%; PenAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Hereditary angioedemaRegistriesSpainBradykininBradykinin B-2 receptor antagonistsIcatibantOn-demand treatmentAttacksManagementSymptomsresearch article34965883open access10.1186/s13223-021-00641-3https://aacijournal.biomedcentral.com/track/pdf/10.1186/s13223-021-00641-3736714300001