Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct;43(5):1181-1190.
doi: 10.1111/ijlh.13465. Epub 2021 Jan 17.

Revisiting the effects of spectral interfering substances in optical end-point coagulation assays

Jansen N Seheult  1   2 , Daniel Dalenberg  3 , Meera R Sridharan  3 , Melissa Stuart  3 , Katherine Moericke  3 , Laynalee Cardel  3 , Nahla Heikal  3 , Dong Chen  3 , Rajiv K Pruthi  3
Affiliations

Revisiting the effects of spectral interfering substances in optical end-point coagulation assays

Jansen N Seheult et al. Int J Lab Hematol. 2021 Oct.

Abstract

Introduction: Hemolysis, icterus, and lipemia (HIL) are common pre-analytical variables in the clinical laboratory. Understanding their effects on coagulation laboratory results is essential.

Methods: HIL effects on the prothrombin time (PT), activated partial thromboplastin time (APTT), dilute Russell's viper venom time (DRVVT), thrombin time (TT), and protein C chromogenic activity (CFx) were evaluated on the ACL TOP 750 optical analyzer and STA-R Evolution mechanical analyzer (PT and APTT only) by spiking normal donor, patient, and commercial control samples with varying concentrations of hemolysate, bilirubin, or a lipid emulsion. The relative difference or bias compared to the original results was determined.

Results: Hemolysis (H) indices up to 900 mg/dL did not affect the APTT, PT, DRVVT Confirm, TT, and CFx; however, H indices above approximately 200 mg/dL resulted in a false-negative DRVVT screen and screen/confirm ratio in samples with a lupus anticoagulant. There was an artifactual prolongation of the PT and APTT when conjugated bilirubin was dissolved in aqueous solvents and not when it was dissolved in dimethyl sulfoxide. Icterus (I) indices up to 45 mg/dL did not result in significant (>15%) bias for all assays evaluated. The PT and APTT assays failed to produce a robust clot curve when the lipemia (L) index exceeded 6000 milliabsorbance units (mAbs), and the TT and DRVVT assays failed when the L index exceeded 3000 mAbs; the CFx assay was unaffected by lipemia.

Conclusions: Verification of the manufacturer's recommended interference thresholds is important since it may avoid inappropriate instrument flagging and/ or sample rejection.

Keywords: blood coagulation tests; hemolysis; icterus; lipemia; methods; spectral interference.

PubMed Disclaimer

References

REFERENCES

    1. Salvagno GL, Lippi G, Bassi A, Poli G, Guidi GC. Prevalence and type of pre-analytical problems for inpatients samples in coagulation laboratory. J Eval Clin Pract. 2008;14(2):351-353.
    1. Lippi G, Plebani M, Favaloro EJ. Interference in coagulation testing: focus on spurious hemolysis, icterus, and lipemia. Semin Thromb Hemost. 2013;39(3):258-266.
    1. Favaloro EJ, Lippi G, Adcock DM. Preanalytical and postanalytical variables: the leading causes of diagnostic error in hemostasis? Semin Thromb Hemost. 2008;34(7):612-634.
    1. Luksic AH, Nikolac Gabaj N, Miler M, Dukic L, Bakliza A, Simundic AM. Visual assessment of hemolysis affects patient safety. Clin Chem Lab Med. 2018;56(4):574-581.
    1. Storti S, Battipaglia E, Parri MS, Ripoli A, Lombardi S, Andreani G. Pre-analytical quality control in hemostasis laboratories: visual evaluation of hemolysis index alone may cause unnecessary sample rejection. J Lab Med. 2019;43(2):67-76.

LinkOut - more resources