title: Deficient activity of von Willebrand factor-cleaving protease in patients with Upshaw-Schulman syndrome.
abstract: We identified unusually large von Willebrand factor (vWF) multimers caused by deficient activity of vWF-cleaving protease in 2 patients with Upshaw-Schulman syndrome. The autoantibodies that inhibited the protease activity were not detected in the plasma of either patient. Periodic fresh-frozen plasma transfusion was effective for management of the hemolysis and thrombocytopenia. We detected enriched enzyme activity in a particular plasma fraction, although molecular cloning of this specific protease is needed to determine a more detailed pathogenesis and to develop new therapeutic approaches.
authors.affiliation: Department of Pediatric Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sasahara
authors.forename: S
authors.initials: S
authors.lastname: Kumaki
authors.forename: Y
authors.initials: Y
authors.lastname: Ohashi
authors.forename: M
authors.initials: M
authors.lastname: Minegishi
authors.forename: H
authors.initials: H
authors.lastname: Kano
authors.forename: F
authors.initials: F
authors.lastname: Bessho
authors.forename: S
authors.initials: S
authors.lastname: Tsuchiya
mesh_terms: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D058186:Acute Kidney Injury / Q000209:etiology; D000328:Adult; D000743:Anemia, Hemolytic / Q000201:enzymology* / Q000235:genetics; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001327:Autoimmune Diseases / Q000201:enzymology* / Q000276:immunology; D001704:Biopolymers; D002543:Cerebral Hemorrhage / Q000209:etiology; D002648:Child; D002908:Chronic Disease; D005260:Female; D005808:Genes, Recessive; D006474:Hemorrhagic Disorders / Q000150:complications / Q000201:enzymology / Q000235:genetics / Q000628:therapy; D006801:Humans; D007564:Japan; D008297:Male; D008666:Metalloendopeptidases / Q000172:deficiency* / Q000235:genetics / Q000276:immunology; D008970:Molecular Weight; D010375:Pedigree; D010949:Plasma; D010974:Platelet Aggregation; D011697:Purpura, Thrombotic Thrombocytopenic / Q000145:classification / Q000175:diagnosis / Q000201:enzymology* / Q000276:immunology / Q000628:therapy; D012008:Recurrence; D013577:Syndrome; D013921:Thrombocytopenia / Q000150:complications / Q000201:enzymology* / Q000235:genetics / Q000628:therapy; D014841:von Willebrand Factor / Q000737:chemistry / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D001704:Biopolymers; D014841:von Willebrand Factor; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human