title: Acquired Dysfibrinogenemia Caused by Autoantibody Inhibiting Fibrin Polymerization in a Patient with MELAS Syndrome and Bleeding Tendency.
abstract: We present a case of acquired dysfibrinogenemia caused by an autoantibody that inhibited fibrin polymerization in a patient previously diagnosed with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes). The patient showed prolonged PT, aPTT, and thrombin time. There was no factor deficiency but fibrinogen antigen and activity were decreased. ELISA for detection of fibrinogen antibodies were performed and IgG purified from the patient's plasma bound to fibrinogen more strongly than did control IgG, indicating the presence of a fibrinogen-specific antibody. Thrombin-mediated fibrin polymerization was severely impaired in the patient, although thrombin-induced fibrinopeptide A release was normal. Scanning electron microscopy was used to investigate the structure of fibrin clots and revealed many pores on the surface of patient's fibrin clots. Since MELAS is often associated with autoimmune disorders, a work-up for the presence of anti-fibrinogen antibody is necessary when bleeding tendency occurs in MELAS patients along with prolonged thrombin time.
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Nuri
authors.initials: N
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Yoo
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: JaYoon
authors.initials: J
authors.lastname: Gu
authors.affiliation: Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.|Department of Biochemistry and Molecular Biology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyori
authors.initials: H
authors.lastname: Kim
authors.affiliation: Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.|Department of Biochemistry and Molecular Biology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Junho
authors.initials: J
authors.lastname: Chung
authors.affiliation: Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.|Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Youngil
authors.initials: Y
authors.lastname: Koh
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea lukekhk@snu.ac.kr.|Cancer Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyun Kyung
authors.initials: HK
authors.lastname: Kim
mesh_terms: D000347:Afibrinogenemia / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D001778:Blood Coagulation Disorders / Q000150:complications*; D018450:Disease Progression; D005260:Female; D005337:Fibrin / Q000378:metabolism* / Q000648:ultrastructure; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D017241:MELAS Syndrome / Q000150:complications* / Q000276:immunology*; D008875:Middle Aged; D010949:Plasma / Q000378:metabolism; D058105:Polymerization
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D005337:Fibrin; D005340:Fibrinogen
keywords: Dysfibrinogenemia; MELAS; autoantibody; bleeding tendency; fibrin polymerization