PB1141 - Modifying clot-fibrinolysis waveform analysis to assess anticoagulant and antifibrinolytic activity exerted by thrombin in the presence of thrombomodulin

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Shusaku Oka, MA (he/him/his)

Clinical Laboratory Technician
Keio University Hospital
shinjuku-ku, Tokyo, Japan

Co-Author(s)

MW

Masatoshi Wakui

Associate Professor
Keio University School of Medicine
shinjuku-ku, Tokyo, Japan
Yuta Fujimori, PhD

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
YK

Yoshino Kondo

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
EO

Emiri Osada

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
SN

Shoko Nakamura

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
YO

Yuko Ozaki

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
TN

Terumichi Nakagawa

Clinical Laboratory Technician
Keio University Hospital
Shinjuku-ku, Tokyo, Japan
HM

Hiromichi Matsushita

Professor
Keio University School of Medicine
Shinjuku-ku, Tokyo, Japan

Background: Thrombomodulin (TM) triggers activation of protein C (PC) and thrombin-activatable fibrinolysis inhibitor (TAFI) by thrombin, which result in anticoagulant and antifibrinolytic activity, respectively. Clot-fibrinolysis waveform analysis (CFWA) is a method that evaluates not only the process of fibrin formation but also the process of dissolving the formed fibrin.

Aims: The present study aimed to assess in vitro TM concentration-dependent effects on coagulation and fibrinolysis through CFWA.

Methods: The samples were prepared by adding various TM concentrations to normal plasma. Addition of the activated partial thromboplastin time (APTT) reagent followed by addition of calcium and tissue plasminogen activator was done to obtain clotting and fibrinolytic reaction curves for APTT-CFWA, which was performed in the automated coagulation system. The positive and negative modes of waveforms were defined as the direction towards fibrin generation and that towards fibrin degradation, respectively. The maximum positive and negative values (Maxp1 and Maxn1) correspond to the maximum coagulation velocity and the maximum fibrinolysis velocity, respectively. Maxp1 time and Maxn1 time were defined as the time when Maxp1 appears and as the time when Maxn1 appears, respectively. The fibrinolysis peak time (FPT) was defined as a time length from Maxp1 time point to Maxn1 time point.

Results: Maxp1 was stationary at TM concentrations ranging from 0 to 2500 ng/mL and decreased at those of 5000 ng/mL or more. Maxn1 exhibited the minimum level at the TM concentration of 625 ng/mL, gradually increased at TM concentrations ranging from 1250 to 5000 ng/mL, and then exhibited a plateau at those of more. The TM concentration-dependent change in FPT and that in Maxn1 were roughly reciprocal.

Conclusion(s): TM-modified CFWA potentially provides findings reflecting anticoagulant activity due to PC activation and antifibrinolytic activity due to TAFI activation, which are caused by thrombin in the presence of TM.