PHILADELPHIA – A draft update of criteria for classifying antiphospholipid syndrome (APS) incorporates a much broader spectrum of disease signs and symptoms, such as kidney disease and more variables for pregnancy, and meets a higher level of specificity than the existing Sapporo criteria, although at the expense of lower sensitivity.
Richard Mark Kirkner/MDedge News
Members of the ACR/EULAR core planning group, (left to right) Dr. Doruk Erkan, Dr. Medha Barbhaiya, and Dr. Stéphane Zuily, presented updated APS criteria at ACR 2022.
Three members of the core planning group that wrote the update, jointly commissioned by the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR), reviewed the proposed criteria at the annual meeting of the ACR.
If ACR and EULAR adopt the new criteria, it would be an update to the Sapporo classification criteria for APS, which was last updated in 2006. The pending criteria consist of the following eight domains encompassing clinical findings and laboratory test results:
- Macrovascular – venous thromboembolism (VTE) with and without high VTE risk profile.
- Macrovascular – arterial thrombosis with and without a high cardiovascular disease risk profile.
- Microvascular – additional categories for kidney disease, pulmonary embolism, and other conditions for both suspected and established APS.
- Obstetric – expanded definitions to account for the absence or presence of preeclampsia or premature birth with or without fetal death.
- Cardiac valve – accounts for thickening and vegetation.
- Hematologic – includes thrombocytopenia (defined as the lowest platelet count, 20-130 x 109/L).
- Antiphospholipid (aPL) test – coagulation-based functional assay, assigning greater weight to persistent over one-time positive test results.
- aPL test by solid-phase assay – includes anticardiolipin enzyme-linked immunosorbent assay (aCL ELISA), and aCL/anti-beta 2 glycoprotein-I (aCL/anti-beta 2 GPI) tests, with greater weight assigned for moderate-to-high positive results depending on isotype, whether immunoglobulin G or M.
Changes from Sapporo criteria
The existing Sapporo criteria include two clinical categories, vascular thrombosis and pregnancy morbidity; and three laboratory categories, positive lupus anticoagulant, medium or high antibody titers, and high aCL/anti-beta 2 GPI measured by ELISA. All of these are included in the draft criteria under two domains.
“These novel clinical features will help us better stratify patients according to the risk factor profile,” Stéphane Zuily, MD, PhD, a vascular specialist and European co-principal investigator of the planning group, said in explaining the proposed updated domains.
“We well-defined the microvascular domain items further than the aPL nephropathy; we redefined pregnancy morbidities; we added cardiac valve disease and thrombocytopenia; and, through gathering novel laboratory features, we were able to quantify single, double, and triple aPL positivity based on different domains and weights,” said Dr. Zuily, professor of medicine at Lorraine University in Nancy, France.
Also noteworthy is the separation of aCL/anti-beta 2 GPI testing by IgG and IgM isotypes. “And we were also able to identify different thresholds in terms of aPL positivity,” Dr. Zuily said.