Tracking of genetic mutations related to hereditary angioedema type III in patients with recurrent angioedema treated at the Clinics Hospital of the State University of Campinas

Abstract

Angioedema is a cutaneous manifestation characterized by soft tissue edema with sudden onset. There are two major endogenous immunologic mediators that are responsible for angioedema episodes: histamine, which is present in allergic reactions, and bradykinin, a substance that is usually linked to inflammatory processes and has been related to non-allergic angioedema episodes. In these cases, there is an abnormal rise in the serum bradykinin (due to mistakes in its regulatory pathway), resulting in vasodilation and an increase of the vessels' permeability, resulting in angioedema. These episodes of angioedema are divided into three categories: Acquired, hereditary, and the ones related to the usage of certain drugs. Classically, hereditary angioedema has been divided in types I and II. Recently, however, a new form of this type was described, known as hereditary angioedema type III or angioedema with normal C1-INH. In this type, which will be the aim of this study, the alterations at the bradykinin pathway found in type I and II are absent, but there are typical manifestations of the disease (such as recurrent edema in the face and in the gastrointestinal tract) in familial patterns, which gives this pathology a hereditary trace. There are, at the present moment, some mutations that have been identified as responsible, at least in part, for manifestations of hereditary angioedema type III. However, these relations still need further studies to be fully elucidated. In Brazil, at the present moment, there's been only one study regarding this type of angioedema, justifying, therefore, the aim of this project, which is to better understand and characterize the presence and influence of these mutations in the Brazilian population. (AU)