Israel Medical Association Journal

Background: Management of patients with hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) is evolving worldwide. Evaluating the Israeli experience may provide valuable insights.

Objectives: To compare demographics and icatibant treatment patterns and outcomes in patients with C1-INH-HAE enrolled in the Icatibant Outcome Survey (IOS) in Israel with those in other countries.

Methods: The IOS is an ongoing observational study that prospectively monitors real-world icatibant safety/tolerability and treatment outcomes.

Results: By July 2016, 58 patients from Israel and 594 patients from other countries were enrolled. Median age at diagnosis (16.7 vs. 21.3 years, P = 0.036) and median delay between symptom onset and diagnosis (0.8 vs. 6.6 years, P = 0.025) were lower in Israel compared with other countries, respectively. Differences in attack severity were not significant (P = 0.156); however, during follow-up, Israeli patients were less likely to miss > 7 days of work/school due to C1-INH-HAE-related complications (P = 0.007). A trend was also shown in Israel for earlier time to treatment (median 0.5 vs. 1.3 hours, P = 0.076), attack duration was shorter (median 5.0 vs. 9.0 hours, P = 0.026), and patients more often self-administered icatibant (97.2% vs. 87.5%, P = 0.003), respectively. However, Israeli patients were less likely to treat attacks (P = 0.036). Whereas patients in Israel reported exclusive use of danazol for long-term prophylaxis, those in other countries used various agents, including C1-INH.

Conclusions: Recognition of C1-INH-HAE and timeliness of icatibant treatment appear more favorable, and attack duration shorter, in Israel compared with other countries.

Hereditary angioedema is a rare genetic disorder, manifested by recurrent edema leading to disfigurement, organ dysfunction and life-threatening respiratory impairment that may become fatal. The hallmark of HAE is a C1 esterase inhibitor deficiency, but recent evidence points at bradykinin as the main mediator that causes hyperpermeability of small vasculature, leading to accumulation of edema fluid. Current therapeutic options for HAE[1] are limited, and consist of drugs, replacement therapy, and supportive treatment. In view of many disadvantages of the current therapeutic modalities new approaches to the treatment of HAE are now being offered. This review summarizes our experience with a new line of medications developed for the treatment of acute exacerbations and prophylaxis of HAE – icatibant: bradykinin receptor antagonist, ecallantide: kallikrein inhibitor, and two C1 INH[2] preparations: Berinert-P, human plasma-derived concentrate, and Rhucin: novel recombinant C1-INH produced in transgenic rabbits. Preliminary results of these studies are encouraging and may bring new hope to the patients with this distressing condition. The exact number of HAE patients in Israel is unknown and because patients are treated individually and comprehensive laboratory assessment is partial, many cases might be missed or not treated according to accepted guidelines. We offer a new specialty center for HAE patients, addressing the medical and psychosocial needs of patients and their families.