title: Acquired angio-oedema caused by IgA paraprotein.
abstract: The syndrome of acquired angio-oedema is characterized by late onset of recurrent bouts of angio-oedema or abdominal pain and may be caused by an acquired deficiency of C1-inhibitor (C1-INH), the inhibitor of the first component of complement. Acquired C1-INH deficiency has been described in approximately 50 patients and is strongly associated with malignant B-cell proliferations. We describe a patient with an 8-year history of recurrent abdominal symptoms and angio-oedema with acquired C1-INH deficiency, caused by the presence of IgA-kappa antibodies that inactivate C1-INH. Analysis of the bone marrow revealed an IgA-kappa monoclonal population of plasma cells, without evidence of overt myeloma. Angio-oedema caused by an autoantibody of the IgA isotype is extremely rare and has never been described in a Dutch patient. Recognition of angio-oedema, both hereditary and acquired, is important because of the therapeutic consequences, as will be discussed.
authors.affiliation: Department of Internal Medicine, Catharina Hospital, Eindhoven, Netherlands. d.j.van.spronsen@int.azg.nl
authors.forename: D J
authors.initials: DJ
authors.lastname: van Spronsen
authors.forename: S J
authors.initials: SJ
authors.lastname: Hoorntje
authors.forename: A J
authors.initials: AJ
authors.lastname: Hannema
authors.forename: C E
authors.initials: CE
authors.lastname: Hack
mesh_terms: D015746:Abdominal Pain / Q000209:etiology / Q000503:physiopathology; D000799:Angioedema / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D003174:Complement C1 Inactivator Proteins / Q000172:deficiency*; D003613:Danazol / Q000627:therapeutic use*; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000150:complications*
chemical_list: D003174:Complement C1 Inactivator Proteins; D007070:Immunoglobulin A; D003613:Danazol