Detecting the presence of a specific factor inhibitor directed against coagulation factor V
Only orderable as part of a profile. For more information see:
5INHE / Factor V Inhibitor Evaluation, Plasma
ALUPP / Lupus Anticoagulant Profile, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
Optical Clot-Based
Plasma Na Cit
Only orderable as part of a profile. For more information see:
5INHE / Factor V Inhibitor Evaluation, Plasma
ALUPP / Lupus Anticoagulant Profile, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
For more information see Coagulation Guidelines for Specimen Handling and Processing.
2 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Detecting the presence of a specific factor inhibitor directed against coagulation factor V
Patient plasma, normal pooled plasma (NPP), and a mixture of patient plasma and NPP are each tested for a specific factor, incubated at 37 degrees C for 1 hour, and then retested for the same factor. In addition, a new mixture of patient plasma and NPP is prepared using the incubated plasmas and tested after the 1 hour incubation. The percentage of the recovered factor for each individual plasma and mixture being tested is calculated and compared. The procedure demonstrates the effect of a specific coagulation factor inhibitor on that factor present in normal pooled plasma over a specific period of time.
An inhibitor directed against a coagulation factor may arise due to multiple exposures from transfusions in a patient deficient in that factor (as in the case of hemophiliacs), in response to certain disease states, or be drug-induced. Nonspecific inhibitors may also be present in patients that will prolong screening tests (eg, prothrombin time and activated partial thromboplastin time). This test is used to qualitatively identify an inhibitor to a specific coagulation factor.
Only orderable as part of a profile. For more information see:
5INHE / Factor V Inhibitor Evaluation, Plasma
ALUPP / Lupus Anticoagulant Profile, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
Negative
When testing is complete, if factor activity results fall within clinically normal ranges, an interpretive comment will be provided noting that inhibitor testing was not indicated and, therefore, not performed. If factor activity indicates the performance of inhibitor screen testing, an interpretive comment will be provided noting the presence or absence of a factor V inhibitor.
Occasionally, a potent lupus-like anticoagulant may cause false-positive testing for a specific factor inhibitor (eg, factor VIII or IX).
1. Bowie EJW, Thompson JH Jr, Didisheim P, Owen CA Jr. Mayo Clinic Laboratory Manual of Hemostasis. WB Saunders Company; 1971:111-115
2. Laboratory Hematology Practice. In: Kottke-Marchant K, ed. Wiley Blackwell Publishing; 2012
3. Hematology: Basic Principles and Practice. In: Hoffman R, Benz EJ Jr, Silberstein LE, eds. Elsevier; 2018
The factor V inhibitor screen is performed on the Instrumentation Laboratory ACL TOP. The assay consists of measuring the factor V activity (prothrombin time based assay) before and after incubation of a mixture of normal plasma and patient's plasma for 1 hour at 37 degrees C. Interpretation of the presence or absence of the indication of a factor V inhibitor is determined by comparing the factor V activity results and the calculated expected values.(Owen CA Jr, Bowie EJW, Thompson JH Jr. The Diagnosis of Bleeding Disorders. 2nd ed. Little Brown and Company; 1975:14-144; Meijer P, Verbruggen HW Spannagi M. Chapter 33: Clotting factors and inhibitors: Assays and Interpretation. In: Kottke-Marchant K, ed. Laboratory Hematology Practice. Wiley Blackwell Publishing; 2012:435-446)
Monday through Friday
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
85335
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
F5_IS | Factor V Inhib Scrn | 81124-0 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
7808 | Factor V Inhib Scrn | 81124-0 |