Cardiolipin Antibody, IgM
Ordering Recommendation

Acceptable initial test when antiphospholipid syndrome (APS) is highly suspected. Order with lupus anticoagulant (LA) (0030181) and anti-beta-2-glycoprotein 1 (anti-beta[2]GP1) IgG and IgM (0050321) assays. Combined IgG and IgM cardiolipin (aCL) antibody test is preferred (0099344).

Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Within 24 hours
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
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
0-12 MPL: Negative
13-19 MPL: Indeterminate
20-80 MPL: Low to Moderately Positive
81 MPL 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.

MPL = IgM phospholipid units
CPT Code(s)
Component Test Code*Component Chart NameLOINC
0050902Cardiolipin Antibody IgM3182-3
* 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 IgM
  • Anti-Cardiolipin
  • Anticardiolipin
  • Anticardiolipin Antibodies
  • Cardiolip