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Is a decrease of microparticles related to improvement of hemostasis after FVIII injection in hemophilia A patients treated on demand?
Author(s) -
Mobarrez F.,
Mikovic D.,
Antovic A.,
Antovic J. P.
Publication year - 2013
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.12103
Subject(s) - hemostasis , fibrinolysis , fibrin , platelet , thrombin , medicine , immunology , coagulation , chemistry
Summary Background Microparticles ( MP s) are small membrane vesicles (0.1–1 μm) released from various cells after activation and/or apoptosis. There are limited data about their role in hemophilia A. Patients and Methods Blood samples were taken before and 30 min after FVIII injection in 18 patients with severe hemophilia A treated on demand. Flow‐cytometric determination of total MP s ( TMP s) using lactadherin, platelet MP s ( PMP s) ( CD 42a), endothelial MP s ( EMP s) ( CD 144) and leukocyte MP s ( LMP s) ( CD 45) was performed. The results were compared with data on endogenous thrombin potential ( ETP ), overall hemostatic potential ( OHP ), fibrin gel permeability and thrombin‐activatable fibrinolysis inhibitor ( TAFI ). Results and Conclusions TMP s and PMP s decreased after treatment (to 1015 ± 221 [ SEM ] and 602 ± 134 × 10 6 L −1 ) in comparison with values before treatment (2373 ± 618 and 1316 ± 331; P < 0.01). EMP s also decreased after treatment (78 ± 12 vs. 107 ± 13; P < 0.05) while LMP s were not influenced. Both TMP and PMP counts were inversely correlated, moderately but statistically significantly, with data on OHP , ETP , fibrin network permeability and TAFI / TAFI i ( P < 0.05 for all). EMP counts were correlated only with ETP ( P < 0.05), while LMP counts did not show any correlation. TMP and PMP counts were also inversely correlated with FVIII levels ( P < 0.05). TMP , PMP and EMP counts decreased after on‐demand treatment with FVIII concentrate in hemophilia A patients. The decrease in circulating MP s, which were inversely correlated with hemostatic activation, may imply that MP s are incorporated in the hemostatic plug formed after FVIII substitution at the site of injury.