title: Plasma centrifugation does not influence thrombin-antithrombin and plasmin-antiplasmin levels but determines platelet microparticles count.
abstract: BACKGROUND
  Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters.
  
  
  METHODS
  Healthy young men were recruited (N=17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500xg for 15 min and (B) at 2500xg for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500xg for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity).
  
  
  RESULTS
  Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P=0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P=0.049). Spearman's rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho=0.52, P<0.050) and between PMPs and CAT for protocol A (rho=0.74, P<0.050) and protocol B (rho=0.78, P<0.050).
  
  
  CONCLUSIONS
  Centrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.
authors.affiliation: Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland ; Laboratory for Molecular Biology and Research, John Paul II Hospital, Krakow, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Stępień
authors.affiliation: Department of Molecular Diagnostics, Holycross Cancer Centre, Kielce, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gruszczyński
authors.affiliation: Laboratory for Molecular Biology and Research, John Paul II Hospital, Krakow, Poland.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Kapusta
authors.affiliation: Department of Molecular Diagnostics, Holycross Cancer Centre, Kielce, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Kowalik
authors.affiliation: Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Wybrańska
mesh_terms: D000328:Adult; D000933:Antifibrinolytic Agents / Q000737:chemistry*; D000990:Antithrombin III / Q000737:chemistry*; D001792:Blood Platelets / Q000737:chemistry*; D055252:Cell-Derived Microparticles; D002498:Centrifugation; D004797:Enzyme-Linked Immunosorbent Assay; D005341:Fibrinolysin / Q000737:chemistry*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D010447:Peptide Hydrolases / Q000737:chemistry*; D010949:Plasma / Q000737:chemistry*
chemical_list: D000933:Antifibrinolytic Agents; C046193:antithrombin III-protease complex; D000990:Antithrombin III; D010447:Peptide Hydrolases; D005341:Fibrinolysin
keywords: blood coagulation tests; cell-derived microparticles; centrifugation; preanalytical phase