When are antiphospholipid-antibody assays indicated?

Note: Measurement of antiphospholipid antibodies is only indicated in specific clinical scenarios that may be associated with antiphospholipid syndrome.
Measurement of aPL antibodies is only indicated in specific clinical scenarios that may be associated with antiphospholipid syndrome; see Clinical scenarios that warrant screening for antiphospholipid antibodies for the scenarios.
Figure 1. Clinical scenarios that warrant screening for antiphospholipid antibodies.

Barbhaiya 2023

The decision to screen patients for antiphospholipid antibodies is usually made in hospital or by a specialist. Two clinical scenarios exist that warrant screening:

  • suspected thrombotic antiphospholipid syndrome, associated with arterial or venous thromboembolism or other specific features, especially at a young age (under 50 years), such as
    • unprovoked venous thromboembolism (eg deep vein thrombosis, pulmonary embolism)
    • nonatherosclerotic stroke or acute myocardial infarctionVaarala, 1998
    • cardiac valve thickening, immune thrombocytopenia, or microvascular features (eg skin lesions, kidney impairment, pulmonary hypertension), in the absence of an alternative explanation
  • suspected obstetric antiphospholipid syndrome, associated with complications, such asSchreiber, 2019
    • recurrent early miscarriage (before 10 weeks’ gestation)—consider screening after 2 early miscarriages; categorically screen after 3 early miscarriages
    • one or more unexplained fetal deaths (of a morphologically normal fetus [ie no chromosomal abnormality or alternative cause of death detected]) at or beyond 10 weeks’ gestation
    • late-pregnancy complications—a history of premature delivery (before 34 weeks’ gestation) due to eclampsia, severe pre-eclampsia, or severe placental insufficiency.