Citation: Ghannam A, Germenis AE and Drouet C. Hereditary Kinin-Mediated Angioedema: Current Challenges. Austin Intern Med. 2016; 1(1): 1002. Austin Intern Med - Volume 1 Issue 1 - 2016 Submit your Manuscript | www.austinpublishinggroup.com Ghannam et al. © All rights are reserved Austin Internal Medicine Open Access desArg 9 -Lys-BK. hese vasoactive peptides, BK, Lys-BK and their metabolites desArg 9 BK, and desArg 9 -Lys-BK interact with G-coupled protein receptors B2R and B1R. Local angioedema attacks depend on the local receptor expression, in particular B1R in inlammatory conditions and its activation by agonists desArg 9 -BK and desArg 9 - Lys-BK.he potency of these agonists to stimulate B1R is not relected by ainity. B1R agonists are with suicient concentration and with long half-life enough to stimulate B1R [6]. Besides, the agonistic activity of desArg 9 -BK for B1R is enhanced by CPM [7]. he main enzyme for desArg 9 -BK catabolism is Aminopeptidase P (APP); its activity in C1-Inh deicient patients’ plasma, inversely correlate with disease severity, supporting a role for desArg 9 -BK in HAE attacks [8]. On the other hand, in FXII-HAE patients, the severity inversely correlate with ACE and CPN activity rather than with APP levels [9]. As far as the genetics of angioedema is considered [10], the main discovery made at the turn of the century is that C1-Inh deiciency is not the only cause of HAE. Cases of inherited angioedema with normal plasma levels of fully functional C1-Inh and without causal mutations at the SERPING1 locus (nlC1-Inh-HAE) are recognized increasingly oten, especially amongst patients sufering from estrogen-associated HAE. Nearly a tenth of nlC1-Inh-HAE cases could be attributed to gain-of-function mutations in the gene encoding the coagulation Factor XII (F12) [11]. Interestingly and on the contrary to the uniform C1-Inh-HAE epidemiology around the world, FXII-HAE seems to be prevalent in certain areas, a fact indicating that the responsible F12 mutations may represent a founder efect. In any case, this discovery signiies that the genetic basis of HAE is far from being completely understood. Since isolated or combined deiciencies in enzymes involved in kinin degradation (carboxypeptidase N, angiotensin-I converting enzyme, APP) have been detected in various forms of kinin-mediated angioedema [12], it is not improbable that in the future, causative alterations in genes other than SERPING1 and F12, will be detected. Moreover, accumulating evidence indicates that functional mutations in genes encoding proteins involved in kinin metabolism and/or function are associated with the severity of C1-Inh-HAE or with the emergence of acquired angioedema. Should these indings will be conirmed, they will explain, at least partially, the enormous clinical heterogeneity of the disease observed even among members of the same family sharing the same SERPING1 causative mutation. Generally, the better understanding of these associations will help to develop strategies to deal with their implications for the individual patient. Besides, in about 5% of C1-Inh-HAE cases, no mutation can be detected in the coding region of SERPING1.But the fact that almost all sufering heterozygotes present with plasma C1-Inh concentration Editorial Firstly described in 1882 by Heinrich Quincke, angioedema was regarded for more than one century as a rare disease [1]. Subsequently, it was established that the hereditary form of the disease (Hereditary Angioedema, HAE) is caused by a deiciency of C1-Inhibitor (C1- Inh) [2] due to alterations in the encoding SERPING1 gene [3] and Bradykinin (BK) was recognized as the principal mediator of HAE symptoms [4]. Over the past decade, however, impressive research advances uncovered an astonishing complexity of the disease. As a result, nowadays, kinin-mediated angioedema is considered as adverse family of disorders, whose the only common characteristics is an unpredictable clinical expression by spontaneous, recurrent, self-limiting but potentially life-threatening attacks of localized edema of subcutaneous and submucosal tissues. hereater, a series of challenging pathophysiological and genetic aspects of the disease that remain to be deciphered, are continuously revealed. Angioedema attacks result from an increased vasopermeability that is induced by the generation of BK through a local process precipitated by systemic contact system activation. Convincing evidence about the systemic kinin formation is that swellings during a given angioedema attack can occur at multiple sites, as well as that inhibitors able to control kallikrein activity reduce vasopermeability and attack severity [5]. C1-Inh is the major control of contact phase proteases, targeting kallikrein and FXIIa. It plays a role in regulating its systemic, luid-phase activation, and in preventing dissemination of contact activation process. herefore, C1-Inh deiciency is associated with uncontrolled contact phase activation and, subsequently, with generation of vasoactive peptides, BK and its active metabolite desArg 9 -BK ater being processed by carboxypeptidases N/M. Another kinin, called kallidin (Lys-BK), can be produced from low molecular weight kininogen. Lys-BK is transformed by carboxypeptidases into Editorial Hereditary Kinin-Mediated Angioedema: Current Challenges Ghannam A 1,2 *, Germenis AE 3,4 and Drouet C 1,5 1 GREPI (Group for Research and Study of Inlammatory Processes) EA7408, Universite Grenoble Alpes, France 2 KininX SAS, Grenoble, France 3 Department of Immunology & Histocompatibility, University of Thessaly, Larissa, Greece 4 Department of Molecular Medicine, Hellenic Pasteur Institute, Athene, Greece 5 Centre de Reference des Angioedemes CREAK, CHU Grenoble Alpes, France *Corresponding author: Arije Ghannam, KininX SAS, Universite Grenoble Alpes, GREPI EA7408, EFS Rhone- Alpes, PO Box 35, 29 Avenue Maquis du Gresivaudan, F-38701 LA TRONCHE, France Received: June 28, 2016; Accepted: June 29, 2016; Published: June 30, 2016