28 APS antibodies: managing patients when laboratory scenarios don’t fit guidelines

Some patients with positive antiphospholipid antibodies (aPL) have not been included in randomised clinical trials or observational registries and, therefore, information on their risk of thrombotic or obstetric recurrence and optimal treatment is scarce.

In this session, the existing evidence regarding the management of two laboratory scenarios not covered by the guidelines is presented: (1) patients with antiphospholipid syndrome (APS) clinical manifestations and anti-phospholipid (aPL) positivity not fulfilling APS laboratory criteria, and (2) the possibility of discontinuing anticoagulation in APS patients whose aPLs become persistently negative.

Growing evidence suggests a role for low titres and ‘non-criteria’ aPL, especially in obstetric APS. Treatment is not formally recommended but might be considered according to the individual’s risk profile. Regarding the question of whether or not to discontinue anticoagulants after the ‘spontaneous’ disappearance of aPL, there is no definite answer. Retrospective studies seem to suggest that withdrawal of anticoagulation could be safe in certain patients with APS, especially in those with a first provoked venous thrombosis and whose aPL became persistently negative during follow-up.^{1 2} Still, before the withdrawal can be recommended in routine clinical practice, multicentre and prospective studies are required to validate this hypothesis.

References

1. Tektonidou MG, et al. EULAR recommendations for the management of antiphospholipid syndrome in adults. Ann Rheum Dis 2019;78:1296–1304.

2. Pires Da Rosa G, et al. Management of patients with antiphospholipid antibodies: what to do in laboratory scenarios that do not fit the guidelines. Expert Rev Hematol 2021;14:457–466.

Learning Objectives

• Explain the main challenges in managing patients with antiphospholipid antibodies when laboratory scenarios don’t fit guidelines

• Describe the options for the treatment of patients in these scenarios

• Discuss new trends in research on new markers for the diagnosis of the antiphospholipid syndrome