When are antiphospholipid-antibody assays not indicated?

Some people have aPL antibodies assayed for undefined indications and are incidentally found to have asymptomatic aPL antibodies. Requesting assays in asymptomatic people is discouraged because aPL antibodies are rare in the general population (in approximately 1 to 5%)Petri, 2000. Testing can cause unwarranted anxiety and trigger unnecessary treatment, resulting in adverse drug effects for an uncertain benefit. Likewise, screening for aPL antibodies is not indicated in the general obstetric population because aPL antibodies are rare in this population.

Approximately 40% of people with SLE have asymptomatic aPL antibodiesPons-Estel, 2017. Screening for aPL antibodies may be considered for people with SLE; however, the decision to screen should only be made by a specialist. In the absence of any clinical manifestations, the presence of aPL antibodies does not constitute a diagnosis of antiphospholipid syndrome. The person may have an increased risk of thromboembolic manifestations or obstetric complications, depending on which aPL antibodies are present and whether they have any other risk factors for thrombosis (eg taking estrogen-containing contraceptives or menopausal hormone therapy).