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Test Code LAAPS2 LA/APS Level 2 Antigenic Package

Specimen and Container/Tube

Specimen Type: Serum

Preferred Specimen: Red Top Tube

Other Acceptable specimens: N/A

Specimen Handling and Transport Instructions

UCMC Onsite Instructions: 

Collect specimen per standard collection procedure and send to laboratory immediately. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

 

UCMC Offsite and UC MedLab Outreach Instructions: 

  • Collect specimen per standard collection procedure.
  • Once each red top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.
  • Specimen should be centrifuged at >2500 x g for 10 minutes.
  • Aliquot removed serum into 3 tubes containing minimum of 0.5 mL of specimen each.
  • Serum samples must then be frozen at -20oC.
  • Once solidly frozen, they must be shipped on dry ice. Samples that have thawed in transit will be rejected.

Rejection Criteria

  • Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits. 
  • Specimens that are clotted or grossly hemolyzed.

Reference Values

 

Test

Age

Sex

Reference Range

Anti-cardiolipin IgA

All

All

Negative: <12.0 APL

Borderline positive: 12.0 - 19.9 APL

Medium positive: 20.0 - 80.0 APL

High positive >80.0 APL

Anti- beta-2 GPI IgA

All

All

<20.1 U/mL

Antiphosphatidylserine/prothrombin IgG

All

All

<30.1 U/mL

Antiphosphatidylserine/prothrombin IgM

All

All

<30.1 CU

Critical Values

Analyte

Unit

Low

High

Age

N/A

 

 

 

 

CPT Codes

86147, 86146, 86148 X2, 85390

LOINC Codes

5076-5, 21108-6, 32032-5, 32033-3

Volume

Preferred Volume: 2 mL serum in 2 aliquots

 

Minimum Volume: 1 mL serum

Specimen Stability

Storage Temperature

Stability

Room temperature

8 hours

Refrigerated

72 hours

Frozen

30 days

Collection Instructions

Collect specimen per standard laboratory collection procedures. 

 

NOTE: Once each blue top tube is completely filled, gently invert the sample tube at least five times to ensure complete mixing of the contents.

Test Components

  • Anti-cardiolipin IgA

  • Anti- beta-2 GPI IgA

  • Anti-phosphatidylserine/prothrombin IgG

  • Anti-phosphatidylserine/prothrombin IgM

  • Pathology interpretation

 

Clinical Indications

The package includes antigenic testing for detection of antiphospholipid antibodies.

Methodology

ELISA

Additional Information

The package includes testing for the presence of IgA  antibodies directed against beta-2 glycoprotein I (beta-2 GPI) and IgG and IgM antibodies directed against phosphatidylserine/prothrombin (APS/PT) complexes .

 

Because the conformational presentation of beta-2 GPI determines whether or not a particular patient antibody will recognize it as an antigenic target, the beta-2 GPI is employed in two different forms. The first employs the beta-2 GPI directly attached to solid phase, and is termed the IgA anti- beta-2 GPI assay.

 

The second employs cardiolipin directly attached to the solid phase, with beta-2 GPI then secondarily being bound to the cardiolipin, and is termed the IgA anti-cardiolipin assay.

 

Turnaround Time

Turnaround times are relative to the time the specimen is received in the test laboratory. 

STAT Turnaround Time: N/A

 

Routine Turnaround Time: 7 days

 

Testing Schedule: Once a week, Wednesdays.

Synonyms/Keyword Search

Lupus; LA; APS; LA/APS; APS/LA, Level 2;
Anticardiolipin IgA Antibodies; Beta-2 Glycoprotein I IgA
Antibodies; Antiphosphatidylserine/prothrombin Antibodies;
LAAPS2

Last Review Date

05/28/2024