Test Id : F7_IS
Factor VII Inhibitor Screen, Plasma
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting the presence of a specific factor inhibitor directed against coagulation factor VII
Method Name
A short description of the method used to perform the test
Only orderable as part of a profile. For more information see:
7INHE / Factor VII Inhibitor Evaluation, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
Optical Clot-Based
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Specimen Type
Describes the specimen type validated for testing
Plasma Na Cit
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Only orderable as part of a profile. For more information see:
7INHE / Factor VII Inhibitor Evaluation, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
For more information see Coagulation Guidelines for Specimen Handling and Processing.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
2 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Cit | Frozen | 14 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting the presence of a specific factor inhibitor directed against coagulation factor VII
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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. Non-specific 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.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Only orderable as part of a profile. For more information see:
7INHE / Factor VII Inhibitor Evaluation, Plasma
ALBLD / Bleeding Diathesis Profile, Limited, Plasma
APROL / Prolonged Clot Time Profile, Plasma
Negative
Interpretation
Provides information to assist in interpretation of the test results
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 VII inhibitor.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Occasionally, a potent lupus-like anticoagulant may cause false-positive testing for a specific factor inhibitor (eg, factor VIII or IX).
Clinical Reference
Recommendations for in-depth reading of a clinical nature
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. 7th ed. Elsevier; 2018
Method Description
Describes how the test is performed and provides a method-specific reference
The factor VII inhibitor screen is performed on the Instrumentation Laboratory ACL TOP. The assay consists of measuring the factor VII 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 VII inhibitor is determined by comparing the factor VII activity results and the calculated expected values.(Owen CA Jr, Bowie EJW, Thompson JH Jr. 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)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
85335
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| F7_IS | Factor VII Inhib Scrn | 81123-2 |
| 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.
|
|---|---|---|
| 7810 | Factor VII Inhib Scrn | 81123-2 |