Successful long-term prophylaxis of hereditary pregnancy-associated angioedema with plasma-derived C1-inhibitor concentrate: a case report

Abstract

Hereditary angioedema (HAE) is a rare autosomal dominant disease caused by quantitative (type I) or functional (type II) deficiency in C1 esterase inhibitor (C1-INH). It may be caused by new mutations in up to 20% of patients. Prevalence of HAE is uncertain but is estimated to be approximately 1 case per 50,000 persons, without known differences among ethnic groups. C1-INH protein is a serine protease inhibitor that is important in controlling vascular permeability by acting on the initial phase of the complement activation, blood clotting, and fibrinolysis. Deficiency in functional C1-INH protein permits release of bradykinin, a key mediator of vascular permeability. Symptoms typically begin since childhood, worsening at puberty, and persist throughout the life, with unpredictable clinical course. The patients with HAE suffer from recurrent, acute attacks of edema that can affect any body sites, causing potentially life-threatening disorders (laryngeal edema). Results of clinical studies show that minor traumas, stress and medical interventions may be frequent precipitants of swelling episodes, but many attacks occur without an apparent cause. Pregnancy-associated hormonal changes may affect the course of C1-INH angioedema attacks by worsening, improving, or having no impact at all, but a higher percentage of pregnant women experienced an increase in C1-INH-HAE attack rates. Therapeutic options for patients with HAE are limited during pregnancy. C1-INH concentrate is recommended as the first-line therapy for pregnant women with HAE for on-demand treatment, shortterm and long-term prophylaxis, due to its safety and efficiency. Other therapies, e.g., treatment with fresh frozen plasma, androgens, icatibant, antifibrinolytics, may show variable efficacy, or cause undesirable side effects. The case below illustrates the successful treatment of HAE in a pregnant woman with C1 esterase inhibitor (C1-INH) concentrate. This patient had a very mild course of HAE during her lifetime and didn’t get any treatment. During pregnancy, she experienced a significant increase in the frequency of attacks, and the decision was made to start replacement therapy with a plasma-derived, double virus-inactivated C1-INH concentrate as a long-term prophylaxis throughout the full term of her pregnancy, before, during and after the cesarean section delivery.