title: Relationship between clotting activity and phosphatidylserine expression on erythrocyte membranes in polycythemia vera patients with the JAK2 V617F mutation.
abstract: BACKGROUND
  Polycythemia vera (PV) accompanies the clinical course of thrombosis. Phosphatidylserine (PS) expression on the plasma membrane has been known to be one of place where the coagulation system activates. We studied the relationship between clotting factor activity and PS expression on the erythrocyte membrane in patients with erythrocytosis.
  
  
  METHODS
  The coagulation test and PS expression in 23 patients with erythrocytosis were measured. PS expression was determined indirectly by measuring annexin V binding to erythrocytes using fluorescence activated cell sorter analysis (FACS).
  
  
  RESULTS
  The activity of clotting factors (II, V, VII, VIII, von Willebrand factor, IX, X) was significantly lower in PV than in the mutation-negative erythrocytosis. There was a significant correlation between reduced activity of clotting factors such as V, X, and IX and increased PS expression of the erythrocyte membrane.
  
  
  CONCLUSIONS
  Increased expression of PS on the erythrocyte membrane may reduce the activities of clotting factors in PV patients with JAK2 V617F mutation.
authors.affiliation: Department of Transfusion Medicine, Tokyo Metropolitan Bokutoh Hospital, 4-23-15 Koutoubashi, Sumida-ku, Tokyo 130-8575, Tokyo, Japan. yuketsuka@bokutoh-hp.metro.tokyo.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
authors.forename: Ryoko
authors.initials: R
authors.lastname: Sakuma
authors.forename: Junji
authors.initials: J
authors.lastname: Tomiyama
authors.forename: Tamae
authors.initials: T
authors.lastname: Hamaki
authors.forename: Akira
authors.initials: A
authors.lastname: Ohwada
authors.forename: Shigeko
authors.initials: S
authors.lastname: Nishimura
mesh_terms: D000328:Adult; D000368:Aged; D017304:Annexin A5 / Q000032:analysis; D001777:Blood Coagulation / Q000235:genetics*; D001779:Blood Coagulation Factors / Q000235:genetics / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000235:genetics / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010718:Phosphatidylserines / Q000097:blood* / Q000235:genetics; D011086:Polycythemia / Q000097:blood* / Q000235:genetics; D011087:Polycythemia Vera / Q000097:blood / Q000235:genetics; D013927:Thrombosis / Q000097:blood* / Q000235:genetics
chemical_list: D017304:Annexin A5; D001779:Blood Coagulation Factors; D010718:Phosphatidylserines; C507924:JAK2 protein, human; D053614:Janus Kinase 2