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Comparison of Fibrinogen Concentrations Determined by the Clauss Method with Prothrombin-Derived Measurements on an
Berrak Guven1, Murat Can1, Abdulkadir Tekin1
1Department of Biochemistry, Faculty of Medicine, Zonguldak Bulent Ecevit University, Zonguldak, Turkey.
Insights
The PT-derived fibrinogen method on the Cobas t511 analyzer shows strong correlation with the Clauss method, particularly for patients with low international normalized ratio (INR). New reference ranges for the PT-derived method are proposed.
Area of Science:
- Clinical Chemistry
- Hematology
- Coagulation Diagnostics
Background:
- Fibrinogen is a critical coagulation factor.
- Assessing fibrinogen levels is essential for diagnosing and managing various diseases.
- Different analytical methods exist for fibrinogen determination, each with potential variations.
Purpose of the Study:
- To compare fibrinogen results from the Clauss and PT-derived methods on the Cobas t511 analyzer.
- To establish reference ranges for both fibrinogen assay methods.
- To evaluate method performance across diverse patient populations and clinical conditions.
Main Methods:
- Retrospective analysis of 914 patient samples.
- Comparison of fibrinogen concentrations using Clauss and PT-derived methods on a Cobas t511 analyzer.
- Data analysis included Passing-Bablok regression and Bland-Altman analysis.
- Reference ranges determined from a healthy outpatient cohort.
Main Results:
- Statistically significant positive correlations were observed between the two methods across most groups (P < 0.05).
- The highest correlation was found in patients with an international normalized ratio (INR) < 1.2.
- Low fibrinogen values showed no significant correlation (P = 0.96).
Conclusions:
- The PT-derived method is a viable alternative to the Clauss method on the Cobas t511, especially for patients with INR < 1.2.
- Established reference ranges for the PT-derived method can aid in clinical interpretation.
- Further research is needed to define specific clinical scenarios where the Clauss method remains preferred.
Background:
This research aims to compare fibrinogen results, obtained from the Clauss and PT-derived method on the Cobas t511 analyzer, in patients with specific categories of disease. A second aim was to determine the reference range for these 2 methods.
Methods:
We retrospectively compared fibrinogen concentrations of 914 patients obtained by the Clauss and PT-derived methods on the Cobas t511 coagulation analyzer from the laboratory information system. Fibrinogen data was segregated into a healthy outpatient population and those populations with possible fibrinogen abnormalities including pregnancy, chronic illness, liver disease, heart and vascular diseases, and clinical suspicion of COVID-19. All data were analyzed using Passing-Bablok regression and Bland-Altman analysis. Reference ranges were determined from fibrinogen results of the healthy outpatient population who presented for a clinic check-up.
Results:
All fibrinogen results were grouped and compared according to fibrinogen values (low, normal, and high), international normalized ratio (INR) values (<1.2, 1.2-2.0, and >2.0), and diagnosis. There were statistically significant positive correlations in all groups (P < 0.05), except for low fibrinogen values (P = 0.96). Results with INR value <1.2 had the highest correlation between 2 methods.
Conclusion:
The PT-derived method can be used alone in the Cobas t511 analyzer, especially in patients with an INR <1.2. Reported new reference ranges of the PT-derived method could help to determine and compare the clinical significance of fibrinogen methods. Further studies must be focused on the conditions in which PT-derived fibrinogen results should be directed to the Clauss test.
