Cardiolipin Antibody, IgG
Ordering Recommendation
Acceptable initial test for strong suspicion of antiphospholipid syndrome. Order with lupus anticoagulant (LA) (0030181) and anti-beta-2-glycoprotein 1 (anti-β2GP1) IgG and IgM (0050321) assays. Combined IgG and IgM cardiolipin (aCL) antibody test (0099344) is preferred.
Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Within 24 hours  
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
Patient Preparation
Serum separator tube.  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.3 mL)  
Storage/Transport Temperature
Unacceptable Conditions
Plasma or other body fluids. Contaminated, heat-inactivated, hemolyzed, or lipemic specimens.  
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year  
Reference Interval
Effective August 18, 2014
0-14 GPL: Negative
15-19 GPL: Indeterminate
20-80 GPL: Low to Moderately Positive
81 GPL or above: High Positive  
Interpretive Data
The persistent presence of IgG and/or IgM cardiolipin (CL) antibodies in moderate or high levels (greater than 40 GPL and/or greater than 40 MPL units or greater than 99th percentile) is a laboratory criterion for the diagnosis of antiphospholipid syndrome (APS). Persistence is defined as moderate or high levels of IgG and/or IgM CL antibodies detected in two or more specimens drawn at least 12 weeks apart (J Throm Haemost. 2006;4:295-306). Lower positive levels of IgG and/or IgM CL antibodies (above cutoff but less than 40 GPL and/or less than 40 MPL units) may occur in patients with the clinical symptoms of APS; therefore, the actual significance of these levels is undefined. 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.  
GPL = IgG phospholipid units
CPT Code(s)
Component Test Code*Component Chart NameLOINC
0050901Cardiolipin Antibody IgG3181-5
* 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.
  • ACA
  • aCL
  • aCL Antibody
  • aCL IgG
  • Anti-Cardiolipin
  • Anticardiolipin
  • Anticardiolipin Antibodies
  • Cardiolip