Thrombin production, inactivation and expression during open heart surgery measured by assays for activation fragments including a new ELISA for prothrombin fragment F1 + 2.
Activation of coagulation was studied during the peri-operative period in patients undergoing cardiopulmonary bypass (CPB) surgery using activation markers which have recently become available: prothrombin fragment F1 + 2 (F1 + 2), which is a measure of total thrombin generation, and thrombin-antithrombin complex, which is a measure of inactivation of free thrombin by antithrombin. Levels of the specific marker of fibrin breakdown, D-dimer, were also determined. F1 + 2 levels were assessed using a newly developed ELISA described herein which employs a neoantigen-specific capture antibody raised using a synthetic peptide; the latter antibody has been pre-adsorbed against prothrombin to ensure high specificity for F1 + 2. Increased generation of thrombin during surgery was clearly demonstrated despite maintenance of a high concentration of heparin during the period of extracorporeal blood circulation. There was a close association (r = 0.882) between the generation of thrombin (F1 + 2 levels) and its inhibition (TAT levels). Differences were noted, however, between the information provided by F1 + 2 and TAT, which are interpreted with regard to the different in vivo fates of F1 + 2 and thrombin. The enhanced activation and inhibition of coagulation observed during CPB was suppressed once physiological blood circulation was restored, with F1 + 2 returning to pre-surgical levels within 24 h after surgery. During the post-operative period D-dimer levels, which rose in concert with F1 + 2 and TAT levels, remained highly elevated, suggesting that not all of the generated thrombin was inactivated by antithrombin.(ABSTRACT TRUNCATED AT 250 WORDS)
Boisclair
M D
MD
Department of Haematology, Charing Cross & Westminster Medical School, London, United Kingdom.
Lane
D A
DA
Philippou
H
H
Sheikh
S
S
Hunt
B
B
D000368:Aged; D000595:Amino Acid Sequence; D000990:Antithrombin III / Q000032:analysis*; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass; D004797:Enzyme-Linked Immunosorbent Assay; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D007432:Intraoperative Period; D008875:Middle Aged; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis*; D010447:Peptide Hydrolases / Q000032:analysis*; D011516:Prothrombin / Q000032:analysis*; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; D010446:Peptide Fragments; C046193:antithrombin III-protease complex; C036309:fibrin fragment D; C045879:prothrombin fragment 1.2; D000990:Antithrombin III; D011516:Prothrombin; D006493:Heparin; D010447:Peptide Hydrolases; D013917:Thrombin