Comorbidities in Angioedema Due to C1-Inhibitor Deficiency: An Italian Survey.

Background: Hereditary angioedema (HAE) due to C1-inhibitor (C1-INH) deficiency is characterized by unpredictable recurrent episodes of swelling affecting the skin and the mucosa tissues, including gastrointestinal tract and/or oropharyngeal-laryngeal mucosae. Long-term prophylaxis (LTP) is used to prevent attacks.

Objective: Because C1-INH plays a pivotal role in several biological pathways, we investigated the possible association of comorbidities with C1-INH deficiency and the use of LTP with attenuated androgens (AA) or tranexamic acid (TXA).

Methods: This retrospective cohort study involved adult patients with HAE referred to Milan and Padua angioedema centers in the period 1979-2021. A qualitative comparison was performed to analyze comorbidities versus general population. The incidence of comorbidities was evaluated during LTP with AA or TXA versus patients without LTP.

Results: A total of 446 patients were studied. A greater prevalence among patients was found for heart diseases (9.6% vs 4.8%), acute myocardial infarction (5.6% vs 1.4%), hepatitis C virus infection (10.5% vs 2.5%), and appendectomy (15.9% vs 4.3%). In patients taking AA, a greater incidence was found for hypertension (22.8% vs 10.8%; odds ratio [OR]: 2.02), hypercholesterolemia (19.5% vs 5.3%; OR: 3.97), diabetes mellitus (5% vs 1.4%; OR: 3.21), hepatic angioma (4.4% vs 0.7%; OR: 8.35), and focal nodular hyperplasia (2.5% vs 0.4%; OR: 6.9). No association between TXA and comorbidities was found.

Conclusion: In this large patient population with a rare disease followed for up to a 43-year period, we found a greater prevalence of comorbidities hitherto unreported in the literature and an association between comorbidities and LTP with AA.