title: Chronic urticaria: a disease at a crossroad between autoimmunity and coagulation.
abstract: Chronic urticaria (CU), defined as recurrence of wheals with or without angioedema for more than 6 weeks, is a quite common disease that may severely worsen the quality of life. Studies carried out during the last 2 decades have demonstrated an autoimmune pathogenesis mediated by functionally active autoantibodies to the high affinity IgE receptor (FcepsilonRI) or to IgE which are able to induce histamine release from basophils and mast cells. However, such mechanism can be detected in less than 50% of patients only. The present article reviews recent findings showing an additional pathogenic mechanisms in CU patients: activation of the coagulation cascade resulting in thrombin production. Thrombin is a serine protease which may play a key role in urticaria, being able to induce edema through an increase in vascular permeability, mast cell activation and degranulation, and to induce the production of the anaphylotoxin C5a. Such mechanism seems to be active in the majority of CU patients, however their relationship with anti-FcepsilonRI or anti-IgE autoantibodies is still matter of research.
authors.affiliation: Ambulatorio di Allergologia, Clinica San Carlo, Paderno Dugnano (MI), Italy. Electronic address: r.asero@libero.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Asero
authors.affiliation: Dipartimento di Medicina Interna, Università di Milano; Allergy, Clinical Immunology & Rheumatology Unit, IRCCS Istituto Auxologico Italiano, Milano, Italy.
authors.forename: Piersandro
authors.initials: P
authors.lastname: Riboldi
authors.affiliation: Unità Operativa di Allergologia e Immunologia Clinica, Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Fondazione IRCCS, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tedeschi
authors.affiliation: Dipartimento di Medicina Interna, Università di Milano, Milano, Italy. Unità Operativa di Medicina Interna 2, Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Fondazione IRCCS, Milano, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Cugno
authors.affiliation: Dipartimento di Medicina Interna, Università di Milano; Allergy, Clinical Immunology & Rheumatology Unit, IRCCS Istituto Auxologico Italiano, Milano, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Meroni
mesh_terms: D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D015551:Autoimmunity / Q000276:immunology; D001491:Basophils / Q000276:immunology / Q000378:metabolism; D001777:Blood Coagulation; D002908:Chronic Disease; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism; D017455:Receptors, IgE / Q000276:immunology; D013917:Thrombin / Q000378:metabolism*; D014581:Urticaria / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*
chemical_list: D001323:Autoantibodies; D017455:Receptors, IgE; D007073:Immunoglobulin E; D013917:Thrombin