title: Von Willebrand factor-cleaving protease (ADAMTS13) in thrombocytopenic disorders: a severely deficient activity is specific for thrombotic thrombocytopenic purpura.
abstract: A severe deficiency in von Willebrand factor-cleaving protease (ADAMTS13) activity (< 5% that in normal plasma) has been observed in most patients with a diagnosis of thrombotic thrombocytopenic purpura (TTP) but not in those with a diagnosis of hemolytic uremic syndrome. However, ADAMTS13 deficiency has been claimed not to be specific for TTP, since it was observed in various thrombocytopenic and other conditions. We studied 68 patients with thrombocytopenia due to severe sepsis or septic shock (n = 17), heparin-induced thrombocytopenia (n = 16), idiopathic thrombocytopenic purpura (n = 10), or other hematologic (n = 15) or miscellaneous conditions (n = 10). Twelve of the 68 patients had subnormal levels of ADAMTS13 activity (<or= 30%), but none had less than 10%. Thus, the study showed that ADAMTS13 activity is decreased in a substantial proportion of patients with thrombocytopenia of various causes. A severe deficiency of ADAMTS13 (< 5%), identified in more than 120 patients during 1996 to 2001 in our laboratory, is specific for a thrombotic microangiopathy commonly labeled TTP.
authors.affiliation: Central Hematology Laboratory, University Hospital, Inselspital, Bern, Switzerland.
authors.forename: Valentina
authors.initials: V
authors.lastname: Bianchi
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Robles
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Alberio
authors.forename: Miha
authors.initials: M
authors.lastname: Furlan
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lämmle
mesh_terms: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008666:Metalloendopeptidases / Q000097:blood / Q000172:deficiency*; D008875:Middle Aged; D011697:Purpura, Thrombotic Thrombocytopenic / Q000201:enzymology; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000201:enzymology*
chemical_list: D015415:Biomarkers; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human