Test Directory

Test Code
PTSAB
Test Name
Phosphatidylserine Autoantibody Profile
CPT Codes
86148 X 3
Included Tests
  • Antiphosphatidylserine IgM
  • Antiphosphatidylserine IgG
  • Antiphosphatidylserine IgA
Expected Turnaround Time
3 - 5 days
Clinical Utility

As an aid in the diagnosis of certain autoimmune thrombotic disorders, such as antiphospholipid syndrome (aPS). Antibodies to PS/PT correlate with the presence of lupus anticoagulants (LA) and this test may be useful in cases with difficult LA test interpretation. This assay may also assist in the determination of risk for thrombosis as well as obstetric complications in patients with antiphospholipid antibodies.

Specimen and Container Info

Specimen Type: Serum

Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 1 mL

Collection Instructions
  1. Collect a gold top, serum separator tube via venipuncture.
Processing and Submission Instructions
  1. Separate serum from cells after clot formation.
  2. Transfer 1 mL of serum to a clear aliquot tube (screw cap).
Transport Instructions

Transport to the laboratory refrigerated. 

Stability Requirements

Room Temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/Thaw Cycles

 Stable x3

Causes for Rejection
  • Gross hemolysis
  • Bacterial contamination
  • Lipemia
Methodology
ELISA
Reference Intervals

 See patient report.

Limitations

•The pathogenic mechanism of aPS-PT antibody morbidity is substantially undefined, although under investigation. To date, aPS/PT antibodies are not included among the formal laboratory classification criteria for APS but are suggested as supplemental assays.

• The clinical significance of PS/PT IgG or IgM antibodies in diseases other than SLE or APS is currently under investigation.

• When negative PS/PT IgG or IgM titers are found in the presence of clinical indications, a lupus anticoagulant, anticardiolipin, anti-β2 or other additional testing is indicated.

• Diagnosis cannot be made on the basis of PS/PT IgG or IgM results alone. These results must be interpreted in conjunction with physical findings.

• Treatment must not be initiated on the basis of a positive PS/PT IgG or IgM titer alone. Supportive clinical indications must also be present.

• It is to be expected that some samples can be anticardiolipin positive and/or anti-β2 GPI positive yet PS/PT IgG or IgM negative. The anti-β2 GPI test is a specific marker of thrombotic risk.

• Patients with APS can be PS/PT positive yet lupus anticoagulant, anticardiolipin or anti-β2 negative.

Alternate Names
  • Antiphosphatidylserine, IgA, IgG, IgM
Reference Lab
Labcorp Of America Holdings
Testing Schedule
Routine, 2 times per week