title: ADAMTS13 phenotype in plasma from normal individuals and patients with thrombotic thrombocytopenic purpura.
abstract: The activity of ADAMTS13, the von Willebrand factor cleaving protease, is deficient in patients with thrombotic thrombocytopenic purpura (TTP). In the present study, the phenotype of ADAMTS13 in TTP and in normal plasma was demonstrated by immunoblotting. Normal plasma (n = 20) revealed a single band at 190 kD under reducing conditions using a polyclonal antibody, and a single band at 150 kD under non-reducing conditions using a monoclonal antibody. ADAMTS13 was not detected in the plasma from patients with congenital TTP (n = 5) by either antibody, whereas patients with acquired TTP (n = 2) presented the normal phenotype. Following immunoadsorption of immunoglobulins, the ADAMTS13 band was removed from the plasma of the patients with acquired TTP, but not from that of normal individuals. This indicates that ADAMTS13 is complexed with immunoglobulin in these patients. The lack of ADAMTS13 expression in the plasma from patients with hereditary TTP may indicate defective synthesis, impaired cellular secretion, or enhanced degradation in the circulation. This study differentiated between normal and TTP plasma, as well as between congenital and acquired TTP. This method may, therefore, be used as a complement in the diagnosis of TTP.
authors.affiliation: Department of Pediatrics, Clinical Sciences Lund, Lund University, 221 84 Lund, Sweden.
authors.forename: Minola
authors.initials: M
authors.lastname: Manea
authors.forename: AnnCharlotte
authors.initials: A
authors.lastname: Kristoffersson
authors.forename: Han-Mou
authors.initials: HM
authors.lastname: Tsai
authors.forename: Wenhua
authors.initials: W
authors.lastname: Zhou
authors.forename: Ingemar
authors.initials: I
authors.lastname: Winqvist
authors.forename: Göran
authors.initials: G
authors.lastname: Oldaeus
authors.forename: Rolf
authors.initials: R
authors.lastname: Billström
authors.forename: Peter
authors.initials: P
authors.lastname: Björk
authors.forename: Lars
authors.initials: L
authors.lastname: Holmberg
authors.forename: Diana
authors.initials: D
authors.lastname: Karpman
mesh_terms: D051722:ADAM Proteins / Q000097:blood / Q000235:genetics*; D000071120:ADAMTS13 Protein; D000328:Adult; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood / Q000235:genetics* / Q000503:physiopathology
chemical_list: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human