title: Endogenous pro-thrombotic biomarkers from the arm and leg may not have the same value.
abstract: OBJECTIVE
  Assessments of endogenous pro-thrombotic biomarkers are performed invariably on arm blood. However, the commonest site for thrombosis is in the leg. A leg blood sample may reflect local pro-thrombotic processes more accurately than systemic arm blood. The aim was to determine whether pro-thrombotic biomarkers from standard venous arm samples differed significantly from leg samples.
  
  
  METHODS
  Concurrent blood samples were taken from an ankle/lower calf varicose vein and an ante-cubital vein in 24 patients awaiting laser treatment as well as age approximated and sex matched healthy controls without venous disease. The following assays were performed: thrombin-antithrombin (ng/ml), antithrombin (%) activity, microparticles (nM), fibrinogen (mg/dl), prothrombin fragment 1.2 (F1.2) (pM) and P-selectin (ng/ml).
  
  
  RESULTS
  Expressed as median (inter-quartile range). Significant arm/leg differences were observed in thrombin-antithrombin, antithrombin, prothrombin fragment 1.2 and P-selectin. The legs of patients had significantly reduced antithrombin activity and P-selectin concentrations compared to their arms (leg: 101 (90-108) versus arm: 112 (99-126), P = 0.001 and leg: 42 (26-52) versus 45 (27-52), P = 0.044, respectively). Control leg samples had significantly increased thrombin-antithrombin and P-selectin compared to control arm samples (leg: 2.1 (0.9-3.2) versus arm: 0.8 (0.5-1.7), P = 0.015 and leg: 36 (24-50) versus arm: 30 (23-41), P = 0.007, respectively). However, the control legs had significantly reduced F1.2 (leg: 265 (230-333) versus arm: 299 (236-361), P = 0.028). No significant arm/leg differences were detected in the microparticle or fibrinogen levels.
  
  
  CONCLUSIONS
  These findings indicate that venous arm blood is significantly different from venous leg blood in four out of six biomarkers studied. Recognition of local venous leg sampling as a site for investigation may unravel why the leg has a greater predisposition to thrombosis and lead the way towards an arm/leg differential test.
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Southall, UK Imperial College, London, UK Department of Vascular Surgery, Northwick Park Hospital, Harrow, UK c.lattimer09@imperial.ac.uk.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Lattimer
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Southall, UK Imperial College, London, UK Hemostasis & Thrombosis Research Laboratories, Loyola University, Maywood, USA.
authors.forename: Evi
authors.initials: E
authors.lastname: Kalodiki
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Southall, UK Imperial College, London, UK Department of Vascular Surgery, Northwick Park Hospital, Harrow, UK.
authors.forename: George
authors.initials: G
authors.lastname: Geroulakos
authors.affiliation: Hemostasis & Thrombosis Research Laboratories, Loyola University, Maywood, USA.
authors.forename: Debra
authors.initials: D
authors.lastname: Hoppensteadt
authors.affiliation: Hemostasis & Thrombosis Research Laboratories, Loyola University, Maywood, USA.
authors.forename: Jawed
authors.initials: J
authors.lastname: Fareed
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001132:Arm; D015415:Biomarkers / Q000097:blood; D001798:Blood Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D013927:Thrombosis / Q000097:blood*; D014648:Varicose Veins / Q000097:blood*
chemical_list: D015415:Biomarkers; D001798:Blood Proteins
keywords: Varicose veins; coagulation; fibrinolysis; thrombophlebitis; venous stasis