PB1013 - Hyperbilirubinemia is a limitation to the overall hemostatic potential assay

Tuesday, June 25, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Co-Author(s)

SN

Sanna Norén

MD
Gastroenterology and Rheumatology Unit, Department of Medicine Huddinge Karolinska Institute & Department of Upper GI Diseases, Division of Hepatology, Karolinska University Hospital Stockholm Sweden
Stockholm, Stockholms Lan, Sweden
NM

Nida Mahmoud Hourani Soutari

Biomedical Analyst
Coagulation, Clinical Chemistry, Department Molecular Medicine & Surgery, Karolinska Institute & Clinical Chemistry & 24/7, Medical Diagnostics Karolinska, Karolinska University Hospital Stockholm Sweden
Stockholm, Stockholms Lan, Sweden
AK

Adrian Kimiaei

MD
Coagulation, Clinical Chemistry, Department Molecular Medicine & Surgery, Karolinska Institute & Clinical Chemistry & 24/7, Medical Diagnostics Karolinska, Karolinska University Hospital Stockholm Sweden
Stockholm, Stockholms Lan, Sweden
JA

Jovan Antovic

MD, Professor
Coagulation, Clinical Chemistry, Department Molecular Medicine & Surgery, Karolinska Institute & Clinical Chemistry & 24/7, Medical Diagnostics Karolinska, Karolinska University Hospital Stockholm Sweden
Stockholm, Stockholms Lan, Sweden
CG

Charlotte Gran

MD, PhD
Coagulation, Clinical Chemistry, Department Molecular Medicine & Surgery, Karolinska Institute & Clinical Chemistry & 24/7, Medical Diagnostics Karolinska, Karolinska University Hospital Stockholm Sweden
Stockholm, Stockholms Lan, Sweden

Presenting Author(s)

Maria Magnusson, MD, PhD

Acting head of Department of Hematology,
Karolinska University Hospital, Karolinska Institutet
Stockholm, Stockholms Lan, Sweden

Background: The hemostatic balance in patients with severe liver disease may be fragile and reliable tests to evaluate the risk of bleeding or thrombosis are requested. Overall hemostatic potential, a global hemostatic assay that evaluates coagulation (OCP), fibrinolysis (OFP), and overall hemostasis (OHP) may be useful. Hyperbilirubinemia secondary to liver disease may cause interference with coagulation assays. OHP results are read spectrophotometrically at 405nm, near the bilirubin absorbance wavelength spectrum. Using a longer wavelength might lessen the effect of bilirubin on the assay.

Aims: We aimed to evaluate the interference of bilirubin and alternative wavelengths on OHP results.

Methods: Pooled plasma from healthy volunteers was measured for levels of conjugated bilirubin using Cobas Pro 8000. Aliquots of plasma were spiked with bilirubin conjugate-dilaurate (Merck, D43593) to end concentrations ranging from 50 to 600 µmol/L and assessed by standard OHP settings (405nm) and 620nm wavelength using an in-house OHP assay. (Antovic A. Semin Thromb Hemost. 2010;36(7):772-9).

Results: In samples measured at 405nm, a negative correlation was observed between increasing levels of bilirubin and the AUC of OHP (fig 1a). OCP increases between 5-17%(fig1b) in samples with bilirubin between 50-250 µmol/L compared to normal bilirubin levels. OFP values increased with elevated bilirubin levels. Bilirubin ≥300 µmol/L yielded no OHP, OCP, or OFP results. In contrast, no missing results were seen with 620 nm, although overall lower values were observed for OHP and OCP. A negative correlation between OHP and bilirubin was observed (fig 1a), with >50% reduction in OHP in samples ≥300 µmol/L. OCP was less affected by increasing bilirubin.

Conclusion(s): Hyperbilirubinemia is a limitation when assessing OHP. Using a longer wavelength of 620 nm might mitigate part of the interference. Our results should be validated, and new reference ranges need to be established. OHP must be used with precaution in patients with hyperbilirubinemia.