Delays between symptom onset and diagnosis of hereditary angioedema (HAE) types 1 and 2 have been decreasing, according to a real-world study that also revealed a younger age at diagnosis in this patient population over time.
The study, “Improvement in diagnostic delays over time in patients with hereditary angioedema: findings from the Icatibant Outcome Survey,” was published in the journal Clinical and Translational Allergy.
Aiming to evaluate if the recent increased awareness of HAE types 1 and 2 translated into an earlier diagnosis, an international team assessed potential changes over time in age at first symptoms, age at diagnosis, and delay in diagnosis in patients enrolled in the Shire-sponsored Icatibant Outcome Survey (IOS).
IOS is an ongoing, multicenter, prospective, observational study (NCT01034969) intended to monitor the safety and effectiveness of Shire’s HAE attack treatment Firazyr (icatibant). As of January 2017, 11 countries were participating in the registry — Austria, Brazil, Czech Republic, Denmark, France, Germany, Greece, Israel, Italy, Spain, and the U.K. IOS is still recruiting, and more information can be found here.
The study analyzed 250 patients (139 females), 240 of whom had HAE type 1 and 10 with type 2. All patients were born before 1990 and diagnosed before 25 years of age. Data were collected between July 2009 and January 2017. No patients diagnosed before onset of symptoms — due to family history of HAE types 1 or 2 — were included.
Median age at symptom onset was 9 years, while age at diagnosis was 16.7 years. The data also showed a median delay in diagnosis of 2.6 years (range 0.1-9.7 years). Of note, the scientists found marked variation among countries, with median ages at onset of symptoms ranging from 0.5 to 12 years, median ages at diagnosis from 13.5 to 22.3 years, and median delays in diagnosis from 0.13 to 17.3 years.
Analysis further showed that the more recent the decade of birth, the younger the age at diagnosis and the shorter the delay in diagnosis. Specifically, the median age of diagnosis was 20.2 years in the 24 patients born from 1950 to 1960 and 15.4 years in the 94 born during 1980-1990. Additionally, the diagnostic delay was seven years in patients born during 1950-1960 and 1.4 years in those born during 1980-1990.
In contrast, age at symptom onset was unchanged throughout the different decades of birth. The 180 patients with a family history of HAE types 1 or 2 had a median delay in diagnosis of two years compared with 5.6 years for those with no or unknown family history.
“Our findings demonstrate improvements in C1-INH-HAE diagnosis over time, with patients now more frequently being diagnosed at a younger age, and with shorter delays between symptom onset and diagnosis,” the scientists wrote. However, improved disease awareness is still needed, given the still-present long delays in diagnosis for some patients, according to them.
The exclusion of patients diagnosed prior to symptom onset precluded proper determination of diagnosis rates for those with a family history of HAE, the team noted. Also, since registry participation is voluntary, there may be missing or incomplete data. Almost two-thirds of patients were born between 1970 and 1990, which indicates a potential bias toward recently diagnosed patients, they cautioned.
Of note, Shire provided funding to support the writing and editing of the study. Two of the authors are employees of Shire. Nine other authors received honoraria, speaker/consulting fees, research/travel funding, acted on medical/advisory boards, and/or participated in clinical trials/registries for the company.