Test Code CHEM18 Alpha-2 Plasmin Inhibitor, Plasma
Additional Codes
A2AP
Specimen Required
Specimen Type: Platelet-poor plasma
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
2. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
3. Aliquot plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.
4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Useful For
Diagnosing congenital alpha-2 plasmin inhibitor deficiencies (rare)
Providing a complete assessment of disseminated intravascular coagulation, intravascular coagulation and fibrinolysis, or hyperfibrinolysis (primary fibrinolysis), when measured in conjunction with fibrinogen, fibrin D-dimer, fibrin degradation products, soluble fibrin monomer complex, and plasminogen
Evaluating liver disease
Evaluating the effects of fibrinolytic or antifibrinolytic therapy
Special Instructions
Method Name
Chromogenic
Reporting Name
Alpha-2 Plasmin Inhibitor, PSpecimen Type
Plasma Na CitSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Clinical Information
Alpha-2 plasmin inhibitor (antiplasmin) is synthesized in the liver with a biological half-life of approximately 3 days. It inactivates plasmin, the primary fibrinolytic enzyme responsible for remodeling the fibrin thrombus, and binds fibrin together with factor XIIIa making the clot more difficult to lyse. Absence of alpha-2 plasmin inhibitor results in uncontrolled plasmin-mediated breakdown of the fibrin clot and is associated with increased risk of bleeding.
Reference Values
Adults: 80-140%
Normal, full-term, and premature infants may have mildly decreased levels (≥50%) that reach adult levels within 90 days postnatal.*
*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing.
Interpretation
Patients with congenital homozygous deficiency (with levels of <10%) are clinically affected (bleeding). Heterozygous individuals having levels of 30% to 60% of mean normal activity are usually asymptomatic.
Lower than normal levels may be suggestive of consumption due to activation of plasminogen and its inhibition by alpha-2 plasmin inhibitor.
The clinical significance of high levels of alpha-2 plasmin inhibitor is unknown.
Cautions
Alpha-2 plasmin inhibitor results are potentially affected by the following:
-Heparin, unfractionated or low-molecular-weight >4 U/mL
-Alpha-2-macroglobulin >7 mg/mL; potentially leading to a falsely increased result
-Hemoglobin >200 mg/dL
-Bilirubin >20 mg/dL
-Triglycerides >1000 mg/dL
Method Description
This assay is performed using the HemosIL Plasmin Inhibitor Kit on the Instrumentation Laboratory ACL TOP Family. Patient plasma, containing alpha-2 plasmin inhibitor, is mixed with reagent containing excess plasmin. Plasmin activity in the reagent is rapidly inhibited by alpha-2 plasmin inhibitor. Residual plasmin activity is then measured using an amidolytic activity assay, in which residual plasmin lyses a synthetic chromogenic substrate and subsequently releases para-nitroanline (detected at 405 nm) to a level that is inversely proportional to the amount of alpha-2 plasmin inhibitor in the sample.(Teger-Nilsson AC, Friberger P, Gyzander E. Determination of a new rapid plasmin inhibitor in human blood by means of a plasmin specific tripeptide substrate. Scand J Clin Lab Invest. 1977;37(5):403-409; package insert: HemosIL Plasmin Inhibitor. Instrumentation Laboratory; 11/2019)
Day(s) Performed
Monday through Friday
Report Available
3 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
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
85410
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
A2PI | Alpha-2 Plasmin Inhibitor, P | 27810-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
A2PI | Alpha-2 Plasmin Inhibitor, P | 27810-1 |
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.