title: Endogenous heparin-like activity detected by anti-Xa assay in infected cirrhotic and non-cirrhotic patients.
abstract: BACKGROUND
  Bacterial infections have been proposed as a trigger for portal hypertensive bleeding in cirrhotic patients. Endogenous low molecular weight heparinoids have been previously detected in vitro by heparinase-modified thromboelastography, but it is not known what type of heparinoids they are. The aim of this study was to assay anti-Xa concentrations to detect heparin activity in infected cirrhotics in vivo.
  
  
  METHODS
  We evaluated 30 cirrhotic patients (15 with bacterial infection, 15 not infected) and 9 non-cirrhotic patients with bacterial infection. The anti-Xa assay was performed at the start of infection in all patients and after resolution of infection in 8 cirrhotics (5 to 10 days after starting antibiotics); thromboelastography (native and heparinase I-modified TEG) was performed in a subgroup of 11 cirrhotic patients with infection, 8 cirrhotics without infection and 8 non-cirrhotics with infection.
  
  
  RESULTS
  Anti-Xa activity was detected in 9 of the 15 infected cirrhotics (60%) and only in 1 of 15 non-infected cirrhotics (6.7%) (P < 0.01). In the infected cirrhotic patients, a heparinase effect was shown in the heparinase I-modified TEG: k time (P < 0.01), alpha-angle (P < 0.01) and r time (P = 0.05), with no effect in the non-infected cirrhotics. Four of 9 (44%) infected non-cirrhotics were positive with the anti-Xa assay.
  
  
  CONCLUSIONS
  In cirrhotic patients, bacterial infections modify haemostasis by producing endogenous heparin-like substances which can inhibit the activated clotting factor X (factor Xa). In infected non-cirrhotics, anti-Xa activity can also be found.
authors.affiliation: Liver Transplantation and Hepatobiliary Medicine, Royal Free Hospital, Pond Street, London NW3 1QG, UK.
authors.forename: A
authors.initials: A
authors.lastname: Zambruni
authors.forename: U
authors.initials: U
authors.lastname: Thalheimer
authors.forename: J
authors.initials: J
authors.lastname: Coppell
authors.forename: A
authors.initials: A
authors.lastname: Riddell
authors.forename: A
authors.initials: A
authors.lastname: Mancuso
authors.forename: G
authors.initials: G
authors.lastname: Leandro
authors.forename: D
authors.initials: D
authors.lastname: Perry
authors.forename: A K
authors.initials: AK
authors.lastname: Burroughs
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001424:Bacterial Infections / Q000150:complications / Q000175:diagnosis*; D016022:Case-Control Studies; D015951:Factor Xa / Q000378:metabolism*; D005260:Female; D006493:Heparin / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013916:Thrombelastography / Q000379:methods
chemical_list: D006493:Heparin; D015951:Factor Xa