A New-Generation Method for Quick and Owren PT

Horsti, Juha; Uppa, Helena; Vilpo, Juhani

doi:10.2174/1874276900802010081

Cited by 4 publications

(9 citation statements)

References 19 publications

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“…The inhibition renders measurement, calibration, and harmonization. 29 , 40 , 41 The therapeutic INR ranges guiding anticoagulant therapy using “old methods” are based on the principle that both calibrators and patient samples have inactive coagulation factors (inhibition) on average, which compensate for each other in the final INR result. Thus the therapeutic ranges are available for the new-generation PT method.…”

Section: Discussionmentioning

confidence: 99%

“…This means difficulties in calibration and harmonization of different reagents. 29 , 41 The harmonization of INR results using different PT methods and reagents is problematic if attempted according to the WHO recommendation. 29 , 43 Measuring only the active coagulation factors without inhibition harmonization between different reagents succeeds well.…”

Section: The New-generation Prothrombin Time Methodsmentioning

confidence: 99%

“… 29 , 43 Measuring only the active coagulation factors without inhibition harmonization between different reagents succeeds well. 41 …”

Section: The New-generation Prothrombin Time Methodsmentioning

confidence: 99%

“… 29 In our earlier studies we measured inactive coagulation factors (inhibition) in four different kits and noted conspicuous variation in inhibition. 40 , 41 ISI calibration should be based on normal plasma and normal plasma dilutions 42 without inactive coagulation factors. In principle, calibrators should not contain inhibitory coagulation factors, which cause error in calibration.…”

Section: Isi Calibrationmentioning

confidence: 99%

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The progress of prothrombin time measurement

Horsti¹

2009

Hematol Rep

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Warfarin is the most widely used medicine for oral anticoagulant therapy (OAT). It inhibits the synthesis of coagulation factors II, VII, IX, and X in the liver and results in the production of inactive or partially active versions of these factors. Inactive coagulation factors interfere with prothrombin time measurement (Quick and Owren PT) measuring the sum of coagulation activity and inhibition. The narrow therapeutic range here involves a danger of serious complications and the risk of bleeding or thrombosis. The new-generation PT method can measure coagulation activity and inhibition separately. This new technique promotes patient care and anticoagulant medication (warfarin, dicoumarol) based on coagulation activity in vivo. Both therapy and laboratory controls should be unquestionably accurate and based solely on in vivo coagulation activity. Inactive coagulation factors (inhibition) render measurement, calibration, and harmonization. The use of the new-generation PT method based on measurement of coagulation activity in vivo could develop vitamin K antagonist (VKA) therapy for the marked benefit of patients.

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Section: Discussionmentioning

confidence: 99%

Section: The New-generation Prothrombin Time Methodsmentioning

confidence: 99%

“… 29 , 43 Measuring only the active coagulation factors without inhibition harmonization between different reagents succeeds well. 41 …”

Section: The New-generation Prothrombin Time Methodsmentioning

confidence: 99%

Section: Isi Calibrationmentioning

confidence: 99%

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The progress of prothrombin time measurement

Horsti¹

2009

Hematol Rep

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“…The recognition and admission of these inconsistencies is gradually gaining attention. May be this new PT method can help to harmonise INR results [22], because we eliminate the effect of inhibition upon measurement and calibration.…”

Section: Discussionmentioning

confidence: 99%

A New Generation Prothrombin Time Method for INR

Horsti

Uppa²,

Vilpo³

2008

Open Med Chem J

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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 (INRAcf) presented in this work develops the PT methodology to measure the true coagulation activity in vivo for patient warfarin therapy without inhibition. INRInh can evidently also be used for the diagnostics and follow-up of certain liver diseases.

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Quick or Owren prothrombin time methods: possibilities and limitations (literature review)

Zatsarynnyi,

Khomenko,

Stadnik

et al. 2024

ЕМ

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Background. To treat patients with hypocoagulation, an objective assessment of the hemostasis system is mandatory. Owren prothrombin time method is rare in Ukrainian hospitals. Objective: in this review, we describe Quick and Owren prothrombin time methods, advantages and limitations of each of them in the treatment of patients with liver failure or anticoagulant users. Materials and methods. Advanced literature search was completed in PubMed, linked with MEDLINE database in English and Google Scholar in Ukrainian. Results. Thirty-four articles met search criteria and were included in the literature review. Conclusions. We can’t compare Quick and Owren prothrombin time methods in seconds and percentages because of different dilution methods. Quick prothrombin time method is more widespread due to the lower costs. Owren prothrombin time method has advantages in patients with hepatobiliar disorders, anticoagulant users and for optimization of the diagnosis of chronic liver failure according to the MELD score for liver transplantation.

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A New-Generation Method for Quick and Owren PT

Cited by 4 publications

References 19 publications

The progress of prothrombin time measurement

The progress of prothrombin time measurement

A New Generation Prothrombin Time Method for INR

Quick or Owren prothrombin time methods: possibilities and limitations (literature review)

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