Antiphospholipid Antibody Testing in a General Population Sample from the USA: An Administrative Database Study

Area of Science:

• Clinical immunology
• Laboratory medicine
• Health services research

Background:

• Antiphospholipid antibodies (aPL) are associated with thrombosis and pregnancy morbidity.
• Standard diagnostic criteria often recommend testing for lupus anticoagulant (LA), anti-cardiolipin (aCL), and anti-beta2-glycoprotein I (aGP1).
• Patterns of aPL testing in large, general population samples are not well-characterized.

Purpose of the Study:

• To characterize the patterns of aPL testing, including the completeness of testing and confirmatory testing rates, in a large US general population.
• To identify potential gaps in current aPL diagnostic workflows.

Main Methods:

• Retrospective analysis of laboratory data from 2010-2015 using the Truven Health MarketScan database.
• Identification of 33,456 individuals with at least one aPL test (LA, aCL, or aGP1).
• Assessment of the proportion of individuals receiving all three tests and the rates of confirmatory testing (≥12 weeks after initial test).

Main Results:

• Only 19% of individuals (6,391/33,456) had all three aPL tests (LA, aCL, aGP1) performed.
• Confirmatory testing was performed in 77% of initially positive LA, 45% of aCL, and 41% of aGP1.
• Only 10.6% (255/2,404) of those re-tested after ≥12 weeks had a confirmatory positive aPL result.

Conclusions:

• aPL testing is frequently incomplete in routine clinical practice.
• The low rate of confirmatory positive aPL tests warrants further investigation into testing protocols and diagnostic yield.
• Optimizing aPL testing strategies may improve diagnostic accuracy and patient management.