Identifying diagnostic testing gaps for antiphospholipid syndrome within a single healthcare system

Antiphospholipid antibody syndrome (APS) is a rare disease with significant morbidity and the possibility of mortality. While there are no established diagnostic criteria for use in clinical settings, there is a large body of global research organized by the American College of Rheumatology and European Alliance of Associations for Rheumatology (ACR/EULAR) into accepted research guidelines, developed for identifying probable APS cases. The research guidelines were used in this study as a surrogate approach for evaluating diagnostic testing patterns, with the aim of identifying potential gaps in patient evaluation for APS in clinical settings. For this study, suggested testing for APS characterization included IgG (Immunoglobulin G) and IgM (Immunoglobulin M) anti-cardiolipin antibodies; IgG and IgM anti-beta-2 glycoprotein I antibodies; and Lupus Anticoagulant. This retrospective cross-sectional study identified patients from the electronic medical records of a regional health system with International Classification of Diseases (ICD) diagnostic codes for APS-associated conditions, signs, symptoms, and/or testing collected for antiphospholipid antibodies in selected medical and surgical specialty locations, from 01/01/2011 to 12/31/2020. These data were used to assess how closely the clinical testing patterns followed the 2023 ACR/EULAR criteria for laboratory evaluation. The data showed that 80.70% of 16679 patients with antiphospholipid antibody tests collected did not include all antiphospholipid antibody testing described in 2023 ACR/EULAR research criteria guidelines. These findings may represent common suboptimal ordering practices in evaluations for APS, highlighting the need for peer comparison and the development of future clinical laboratory guidance to support more complete assessment for APS.