title: Influence of storage time and temperature on international normalized ratio (INR) levels and plasma activities of vitamin K dependent clotting factors.
abstract: We designed this study to assess the effect of storage time and temperature on the international normalized ratio (INR) levels and plasma activities of vitamin K-dependent, clotting factors. A total of 100 subjects, comprising 34 healthy controls, 33 patients with liver cirrhosis and 33 patients on long-term coumarin therapy were enrolled. After centrifugation of collected specimens, aliquots of plasma were stored at room temperature (20 -22 degrees C), refrigerated at 2-6 degrees C and frozen at -40 degrees C. Determinations of INR and plasma activities of clotting factors II, VII, IX and X were performed immediately after sampling (0 time) and after 6, 12 and 24 h. We found no significant change of either INR levels or plasma activity of any of the studied clotting factors up-to 24 h at different studied temperatures (p >0.05). Our data demonstrates that clinical specimens for determination of INR levels and plasma activities of factors II, VII, IX and X are acceptable for testing for up-to 24 h whatever may be the temperature of storage.
authors.affiliation: Hematology Unit, Clinical Pathology Department, Al-Mansoura Faculty of Medicine, Al-Mansoura, Egypt. awad_mohamed_eg@yahoo.com
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Awad
authors.forename: Tarek E
authors.initials: TE
authors.lastname: Selim
authors.forename: Fatma A
authors.initials: FA
authors.lastname: Al-Sabbagh
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000187:drug effects / Q000378:metabolism; D003374:Coumarins / Q000627:therapeutic use; D015925:Cryopreservation; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008103:Liver Cirrhosis / Q000097:blood; D008297:Male; D010949:Plasma; D012034:Refrigeration; D014812:Vitamin K / Q000378:metabolism
chemical_list: D000925:Anticoagulants; D001779:Blood Coagulation Factors; D003374:Coumarins; D014812:Vitamin K; C030123:coumarin