Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Highly sensitive thromboplastins do not improve INR precision

V L Ng1, R Valdes-Camin, E L Gottfried

  • 1Department of Laboratory Medicine, School of Medicine, University of California San Francisco, and San Francisco General Hospital, 94110, USA.

American Journal of Clinical Pathology
|March 12, 1998
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Isolated vascular "v" lesions in liver allografts: How to approach this unusual finding.

American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons·2018
Same author

Patterns of kidney injury in pediatric nonkidney solid organ transplant recipients.

American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons·2017
Same author

Simultaneous liver-pancreas transplantation for cystic fibrosis-related liver disease: a multicenter experience.

Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society·2014
Same author

Long-term follow-up of portal hypertension after liver transplantation in children.

Pediatric transplantation·2008
Same author

Alosetron repeat dose pharmacokinetics, effects on enzyme activities, and influence of demographic factors.

Alimentary pharmacology & therapeutics·2004
Same author

In vivo emergence of drug-resistant mutations at less than 50 HIV-1 RNA copies/mL that are maintained at viral rebound in longitudinal plasma samples from human immunodeficiency virus type-1-infected patients on highly active antiretroviral therapy.

Journal of human virology·2002
Same journal

Invasive urothelial carcinoma in association with surface low-grade papillary urothelial carcinoma: clinical and pathologic insights from a rare entity.

American journal of clinical pathology·2026
Same journal

CEACAM1 expression by immunohistochemistry in B-cell lymphomas and plasma cell myeloma.

American journal of clinical pathology·2026
Same journal

Comprehensive multicriteria life cycle assessment of biopsy processing in a surgical pathology department.

American journal of clinical pathology·2026
Same journal

Prognostic significance of Myb protein and its downstream target genes in lacrimal gland adenoid cystic carcinoma.

American journal of clinical pathology·2026
Same journal

Mismatch repair protein "nonclassic expression loss" pattern in colorectal cancer: an important staining pattern that is not well understood.

American journal of clinical pathology·2026
Same journal

Musculoskeletal pain in medical laboratory personnel: a cross-sectional study.

American journal of clinical pathology·2026
See all related articles

Highly sensitive thromboplastin reagents do not guarantee consistent International Normalized Ratio (INR) results. This study found significant variability, questioning the current INR standardization for oral anticoagulant therapy.

Area of Science:

  • Clinical Chemistry
  • Hematology
  • Medical Diagnostics

Background:

  • The International Normalized Ratio (INR) system aims to standardize prothrombin time (PT) for oral anticoagulant therapy.
  • Highly sensitive thromboplastin reagents with an International Sensitivity Index (ISI) ≤ 1.2 are recommended to minimize interlaboratory variability.

Purpose of the Study:

  • To evaluate the consistency of INR values obtained using "highly sensitive" thromboplastin reagents and automated analyzers.
  • To determine if current INR measurement methods achieve standardization goals.

Main Methods:

  • Compared INR values from 69 patient specimens using four thromboplastin preparations (ISI 0.96-1.10) on two automated photo-optical analyzers.
  • Utilized multivariate analysis on 552 INR values to assess reagent-coagulometer combinations and normalization.

Related Experiment Videos

  • Assessed clinical significance of INR differences by categorizing values into therapeutic ranges.

    • Main Results:

    • Eight reagent-coagulometer combinations did not yield equivalent INR values.
    • INR values were not normalized even with local ISI assignments.
    • Significant discordance (17%-29%) in paired thromboplastin values occurred across therapeutic categories.

    Conclusions:

    • The current INR system, even with highly sensitive reagents, fails to achieve standardized prothrombin time values.
    • The recommendation to exclusively use highly sensitive reagents for oral anticoagulant therapy regulation is not supported by these findings.