UCSD Musculoskeletal Radiology


Coagulation reference




<>The Special Coagulation laboratory is pleased to announce the completion of the migration of all routine and special coagulation tests to the new Beckman ACL TOP Coagulation Analyzers.  This will significantly improve the turnaround times for many assays and allow us to accommodate stat requests that had not been possible with the old methodologies.

As we have gained experience with the new analyzers, minor adjustments to the current normal ranges for PT and APTT have become necessary.  While all new or adjusted normal ranges and cut off points are available in PCIS, it is worthwhile to point out the new normal ranges and cut off points as follows:


Routine Coagulation tests normal ranges

PT                               7-10 sec

APTT                          25-34 sec

D-Dimer HS                240 ng/ml or less is a negative test

Fibrinogen                   200-450 mg/dl


Special Coagulation tests normal ranges

Clotting factor activities:

            Factor II                      80-140%

            Factor V                      50-145%

            Factor VII                    65-125%

            Factor X                      70-150%

            Factor VIII                   55-140%

            Factor IX                     65-135%

            Factor XI                     75-165%

            Factor XII                    60-140%


Von Willebrand antigen          60-160%

Von Willebrand activity          55-150%


Protein C activity                    70-160%

Free protein S antigen             65-145%

Antithrombin activity              80-140%


Dilute Russell Viper Venom test

DRVVT Ratio                                     <1.20  is normal

DRVVT-confirm Test Ratio*              >1.12  confirms the presence of a lupus anticoagulant


*Note that the DRVVT-confirm Test Ratio is a new parameter with a new cut off value.  The Test Ratio replaces the previous DRVV-confirm ratio, which had a cut off value of 1.20.  Please refer to the PCIS Results Detail screens for more information and clinical interpretation.