Long-term outcome of C1-esterase inhibitor deficiency

Hereditary angioedema (HAE) is a rare hereditary disorder characterized by episodic swelling and life-threatening airway obstruction caused by laryngeal angioedema. In most HAE patients, reduced level of serum C1-Inhibitor (type-I-HAE) or presence of aberrant C1-Inhibitor (type-II-HAE) result in the lost of regulation of the complementary system and contact activation system with downstream over-activation of bradykinin – the chief mediator leading to angioedema. Type-III HAE (HAE-nl-C1INH) is rare without deficient or dysfunction of C1-Inhibitor, often with genetic aberrant related to the contact activation system. The prevalence of HAE in the population is estimated at 1 in 50,000 individuals, often with early onset, but due to the heterogeneity of the disease, there is frequently a significant delay in diagnosis. Recently, better awareness by physicians, more access to diagnostic tools, better management and prophylaxis has decreased morbidity and mortality. A focus in HAE patient care shift from management of attacks with on-demand medication, to use of prophylaxis to reduce attacks has improved the overall quality of life of patients with HAE. One area in HAE research that has not been emphasized is the long-term consequence of C1-INH deficiency in HAE patients, other than the typical manifestations of HAE, as evidence have emerged linking this disorder with increased risk of cardiovascular diseases, auto-immune disorders, and malignancy. This review aims to gather the current knowledge and evidence of potential consequence of C1-Inhibitor deficiency in HAE aside from angioedema with emphasis in the improvement of long-term care and overall quality of life for HAE patients.