Test Code PSPT Phosphatidylserine/Prothrombin Antibody, IgG and IgM, Serum
Reporting Name
PS/PT Ab, IgG/IgM, SUseful For
May be useful for the evaluation of patients with prior positive lupus anticoagulant results who are on direct oral anticoagulant therapy
May be useful as a risk marker for thrombosis in antiphospholipid antibody carriers
Performing Laboratory

Specimen Type
SerumOrdering Guidance
Cardiolipin and beta-2 glycoprotein testing are the first-tier test options for most patients. Phosphatidylserine/prothrombin antibodies are considered part of the second-tier workup.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 21 days | |
Frozen | 21 days |
Reference Values
Negative ≤30.0 U
Borderline 30.1-40.0 U
Positive ≥40.1 U
Day(s) Performed
Wednesday
Test 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
86148 x 2
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PSPT | PS/PT Ab, IgG/IgM, S | 97026-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
PSPTM | PS/PT Ab, IgM, S | 85358-0 |
PSPTG | PS/PT Ab, IgG, S | 85359-8 |
Clinical Reference
1. Miyakis S, Lockshin MD, Atsumi T, et al: International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost. 2006 Feb;4(2):295-306. doi: 10.1111/j.1538-7836.2006.01753.x
2. Pengo V, Bison E, Denas G, Jose SP, Zoppellaro G, Banzato A: Laboratory diagnostics of antiphospholipid syndrome. Semin Thromb Hemost. 2018 Jul;44(5):439-444. doi: 10.1055/s-0037-1601331
3. Tebo AE: Laboratory evaluation of antiphospholipid syndrome: An update on autoantibody testing. Clin Lab Med. 2019 Dec;39(4):553-565. doi: 10.1016/j.cll.2019.07.004
4. Sciascia S, Sanna G, Murru V, Roccatello D, Khamashta MA, Bertolaccini ML: Anti-prothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies and the risk of thrombosis in the antiphospholipid syndrome: A systematic review. Thromb Haemost. 2014 Feb;111(2):354-364. doi: 10.1160/TH13-06-0509
5. Amengual O, Forastiero R, Sugiura-Ogasawara M, et al: Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study. Lupus. 2017 Mar;26(3):266-276. doi: 10.1177/0961203316660203
6. Heikal NM, Jaskowski TD, Malmberg E, Lakos G, Branch DW, Tebo AE: Laboratory evaluation of anti-phospholipid syndrome: A preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at-risk patient cohort. Clin Exp Immunol. 2015 May;180(2):218-226. doi: 10.1111/cei.12573
7. Nakamura H, Oku K, Amengual O, et al: First-line, non-criterial antiphospholipid antibody testing for the diagnosis of antiphospholipid syndrome in clinical practice: A combination of anti-beta 2 -glycoprotein I domain I and anti-phosphatidylserine/prothrombin complex antibodies tests. Arthritis Care Res (Hoboken). 2018 Apr;70(4):627-634
8. Radin M, Foddai SG, Cecchi I, et al: Antiphosphatidylserine/prothrombin antibodies: An update on their association with clinical manifestations of antiphospholipid syndrome. Thromb Haemost. 2020 Apr;120(4):592-598. doi: 10.1055/s-0040-1705115
9. Nunez-Alvarez CA, Hernandez-Molina G, Bermudez-Bermejo P, et al: Prevalence and associations of anti-phosphatidylserine/prothrombin antibodies with clinical phenotypes in patients with primary antiphospholipid syndrome: aPS/PT antibodies in primary antiphospholipid syndrome. Thromb Res. 2019 Feb;174:141-147. doi: 10.1016/j.thromres.2018.12.023
10. Tonello M, Mattia E, Favaro M, et al: IgG phosphatidylserine/prothrombin antibodies as a risk factor of thrombosis in antiphospholipid antibody carriers. Thromb Res. 2019 May;177:157-160. doi: 10.1016/j.thromres.2019.03.006
Method Description
The QUANTA Lite sPS/PT assay is an enzyme-linked immunosorbent assay. Briefly, purified phosphatidylserine/prothrombin (PS/PT) complex is coated onto a 96-well plate. Calibrators, controls, and diluted patient samples are added to the wells of the plate. If present, IgG antibodies or IgM antibodies to the PSPT complex will bind during an incubation step. After a wash step, an antihuman IgG or IgM horseradish peroxidase-labelled conjugate is added. After another incubation and wash step, a peroxidase substrate solution is added, which will change color in the presence of the conjugated enzyme. Lastly, the reaction is stopped by the addition of 0.44 M sulfuric acid. The absorbance of the colored produced is proportional to the amount of IgG or IgM PS/PT antibodies in the sample. Control and patient results are calculated based on a curve generated from the kit calibrators.(Packet inserts: QUANTA Lite aPS/PT, IgG ELISA kit. INOVA Diagnostics; Rev. 2, 1/2016; QUANTA Lite aPS/PT, IgM ELISA kit. INOVA Diagnostics; Rev. 4, 09/2018)
Report Available
2 to 8 daysReject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | OK |
Method Name
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
PSPTG | PS/PT Ab, IgG, S | Yes | Yes |
PSPTM | PS/PT Ab, IgM, S | Yes | Yes |