Cargando…

A New Generation Prothrombin Time Method for INR

Prothrombin time (PT) is the leading test for monitoring oral anticoagulation therapy (OAT). We sought to determine INR taking into account only active coagulation factors FII, FVII and FX without inhibition in patient plasmas and calibrator kits. We measured PT using a combined thromboplastin reage...

Descripción completa

Detalles Bibliográficos
Autores principales: Horsti, Juha, Uppa, Helena, Vilpo, Juhani A
Formato: Texto
Lenguaje:English
Publicado: Bentham Science Publishers Ltd. 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709469/
https://www.ncbi.nlm.nih.gov/pubmed/19662139
http://dx.doi.org/10.2174/1874104500802010011
_version_ 1782169296386916352
author Horsti, Juha
Uppa, Helena
Vilpo, Juhani A
author_facet Horsti, Juha
Uppa, Helena
Vilpo, Juhani A
author_sort Horsti, Juha
collection PubMed
description Prothrombin time (PT) is the leading test for monitoring oral anticoagulation therapy (OAT). We sought to determine INR taking into account only active coagulation factors FII, FVII and FX without inhibition in patient plasmas and calibrator kits. We measured PT using a combined thromboplastin reagent. The calculation was based on a new PT method, which measures active coagulation factors (F II, F VII, FX) and corrects the errors caused by inactive coagulation factors. On this basis, an INR result with and without inhibition for individual patient samples was also calculated and applied to 200 plasma samples obtained from OAT patients. Conspicuous variation in inhibition between the four calibration kits was noted. The kinetics of this inhibition was closest to a noncompetitive pattern. The need of correction for INRs of single patients increases with higher INRs. At the same level of patient INRs the coagulation inhibiton varies markedly. It has been known that different thromboplastin reagents possess variable sensitivities, but this may depend on sensitivity in inactive coagulation factors. PT methods today measure the sum of active coagulation factors and inhibition of inactive coagulation factors. ISI calibrators contain variable amounts of inactive coagulation factors, which renders harmonisation of INR results. Application of the Acf-PT (INR(Acf)) presented in this work develops the PT methodology to measure the true coagulation activity in vivo for patient warfarin therapy without inhibition. INR(Inh) can evidently also be used for the diagnostics and follow-up of certain liver diseases.
format Text
id pubmed-2709469
institution National Center for Biotechnology Information
language English
publishDate 2008
publisher Bentham Science Publishers Ltd.
record_format MEDLINE/PubMed
spelling pubmed-27094692009-08-06 A New Generation Prothrombin Time Method for INR Horsti, Juha Uppa, Helena Vilpo, Juhani A Open Med Chem J Article Prothrombin time (PT) is the leading test for monitoring oral anticoagulation therapy (OAT). We sought to determine INR taking into account only active coagulation factors FII, FVII and FX without inhibition in patient plasmas and calibrator kits. We measured PT using a combined thromboplastin reagent. The calculation was based on a new PT method, which measures active coagulation factors (F II, F VII, FX) and corrects the errors caused by inactive coagulation factors. On this basis, an INR result with and without inhibition for individual patient samples was also calculated and applied to 200 plasma samples obtained from OAT patients. Conspicuous variation in inhibition between the four calibration kits was noted. The kinetics of this inhibition was closest to a noncompetitive pattern. The need of correction for INRs of single patients increases with higher INRs. At the same level of patient INRs the coagulation inhibiton varies markedly. It has been known that different thromboplastin reagents possess variable sensitivities, but this may depend on sensitivity in inactive coagulation factors. PT methods today measure the sum of active coagulation factors and inhibition of inactive coagulation factors. ISI calibrators contain variable amounts of inactive coagulation factors, which renders harmonisation of INR results. Application of the Acf-PT (INR(Acf)) presented in this work develops the PT methodology to measure the true coagulation activity in vivo for patient warfarin therapy without inhibition. INR(Inh) can evidently also be used for the diagnostics and follow-up of certain liver diseases. Bentham Science Publishers Ltd. 2008-02-27 /pmc/articles/PMC2709469/ /pubmed/19662139 http://dx.doi.org/10.2174/1874104500802010011 Text en Bentham Science Publishers Ltd. http://creativecommons.org/licenses/by/2.5/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/) which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Article
Horsti, Juha
Uppa, Helena
Vilpo, Juhani A
A New Generation Prothrombin Time Method for INR
title A New Generation Prothrombin Time Method for INR
title_full A New Generation Prothrombin Time Method for INR
title_fullStr A New Generation Prothrombin Time Method for INR
title_full_unstemmed A New Generation Prothrombin Time Method for INR
title_short A New Generation Prothrombin Time Method for INR
title_sort new generation prothrombin time method for inr
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709469/
https://www.ncbi.nlm.nih.gov/pubmed/19662139
http://dx.doi.org/10.2174/1874104500802010011
work_keys_str_mv AT horstijuha anewgenerationprothrombintimemethodforinr
AT uppahelena anewgenerationprothrombintimemethodforinr
AT vilpojuhania anewgenerationprothrombintimemethodforinr
AT horstijuha newgenerationprothrombintimemethodforinr
AT uppahelena newgenerationprothrombintimemethodforinr
AT vilpojuhania newgenerationprothrombintimemethodforinr