Ordering Recommendation

Preferred second-line test when seronegative antiphospholipid syndrome (APS) is strongly suspected. Order incrementally or concurrently with other noncriteria antiphospholipid antibody tests.

Mnemonic
PROTHROM G
Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Performed

Mon

Reported

1-8 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Serum separator tube or lt. blue (sodium citrate).

Specimen Preparation

Transport 0.5 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.3 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Hemolyzed or lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year

Reference Interval

Effective 5/21/2018
Less than 20 Units

Interpretive Data

IgG antibodies to prothrombin may be a risk factor for either venous or arterial thrombosis in antiphospholipid syndrome (APS). Strong clinical correlation is recommended in the absence of lupus anticoagulant, IgG and/or IgM cardiolipin and/or beta2 glycoprotein antibodies.

If results are positive, repeat testing with two or more specimens drawn at least 12 weeks apart to demonstrate persistence of antibodies.

Results should not be used alone for diagnosis and must be interpreted in light of APS-specific clinical manifestations and/or other criteria phospholipid antibody tests.

Compliance Category

FDA

Note
Hotline History
N/A
CPT Codes

86849

Components
Component Test Code* Component Chart Name LOINC
0051302 Prothrombin Antibody, IgG 40595-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Prothrombin IgG
Prothrombin Antibody, IgG