The Coagulation Conundrum: Mixing Studies in Detecting Factor Deficiencies
Explore the evolution, methods, and limitations of mixing studies in coagulation testing.
Introduction to Mixing Studies
Mixing studies have traditionally been used to differentiate factor deficiencies from other coagulation disorders.
Historical Overview
Mixing studies were instrumental in the discovery of coagulation factors and have been used for centuries.
Limitations of Mixing Studies
The test lacks standardization due to variable sensitivity of PT and APTT reagents for factor deficiencies and non-specific inhibitors, such as drugs and lupus anticoagulants (LA).
Advantages and disadvantages of recommended methods to interpret mixing studies will be discussed, including:
- Correction into the reference range
- Percentage correction
- The Rosner index
- Estimated factor correction
Comparing the accuracy of these cut-off methods will provide insights into single factor deficiency vs. other coagulation disorders.
Author's summary: Evolution and limitations of mixing studies in coagulation testing.