title: Autoantibodies against the protease inhibitor calpastatin: a new risk factor for venous thrombosis?
abstract: Autoantibodies reactive against human calpastatin were detected by screening a cDNA expression library with the serum of a 53 year old white female patient with a history of venous thrombosis and suspected antiphospholipid syndrome. When further sera were analyzed it could be shown that > 90% of calpastatin autoantibodies, detected by Western blotting against the partial calpastatin clone, react with the C-terminal amino acids of the protein. Therefore, an ELISA based on a synthetic peptide containing the C-terminal 27 amino acids of calpastatin was developed and 205 healthy blood donors and 138 random sera from hospital patients were analyzed. A total of 11 sera (3.2%) were positive with no significant difference between the two groups (7/205 and 4/138). In 80 consecutive patients with a history of venous thrombosis 9 positive sera (11.3%; p < 0.01 vs. blood donors, p < 0.02 vs. hospital patients) were detected. Our results indicate that autoantibodies against calpastatin may constitute a so far unknown risk factor for venous thrombosis.
authors.affiliation: Institut für Klinische Chemie, Universität Regensburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Schlosser
authors.forename: K J
authors.initials: KJ
authors.lastname: Lackner
authors.forename: C
authors.initials: C
authors.lastname: Scheckenhofer
authors.forename: M
authors.initials: M
authors.lastname: Spannagl
authors.forename: F A
authors.initials: FA
authors.lastname: Spengel
authors.forename: G
authors.initials: G
authors.lastname: Hahn
authors.forename: B
authors.initials: B
authors.lastname: Lang
authors.forename: G
authors.initials: G
authors.lastname: Schmitz
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology; D002135:Calcium-Binding Proteins / Q000276:immunology*; D015853:Cysteine Proteinase Inhibitors / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013924:Thrombophlebitis / Q000209:etiology / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D002135:Calcium-Binding Proteins; D015853:Cysteine Proteinase Inhibitors; C033668:calpastatin