Thrombotic risk assessment in patients with systemic lupus erythematosus: Validation of the adjusted-Global Antiphospholipid Syndrome Score (aGAPSS) in Thai patients

Abstract

Background: The adjusted-Global Antiphospholipid Syndrome Score (aGAPSS) has been validated and used to predict antiphospholipid antibodies (aPL) related to vascular thrombosis (VT). Objective: To validate aGAPSS for predicted aPL-related VT and pregnancy complications (PC) in Thai systemic lupus erythematosus (SLE) patients. Methods: A cross-sectional study was performed among Thai SLE patients with clinical manifestations; history of VT and PC, cardiovascular risk factors, and aPL profiles were collected. The aGAPSS was calculated from the sum of the risk factors (hyperlipidemia = 3.0, arterial hypertension = 1.0, anti-cardiolipin antibody = 5.0, anti-b2 glycoprotein I antibody = 4.0, and lupus anticoagulant = 4.0). Results: Of 132 SLE patients, 12 (9.1%) had VT and 5 (4.1%) had PC. When comparing the aGAPSS (median; interquartile range [IQR]) of patients with events (VT and/or PC) (6.5; IQR 3.3-9.0), VT (8.0; IQR 4.0-9.0), arterial thrombosis (3.5; IQR 1.0-5.8), and PC (9.0; IQR 8.0-11.5), and the aGAPSS of patients without an event (3.0; IQR 0-4.0), aGAPSS of patients with events was significantly higher, except in patients with arterial thrombosis. An aGAPSS of 4.5 or more was associated with risk of aPL-related VT (sensitivity 71.4%, specificity 76.7%), and an aGAPSS of 6.0 or more was associated with risk of aPL-PC (sensitivity 100%, specificity 84.0%). Conclusion: The aGAPSS could predict the risk of aPL-PC and aPL-related VT in Thai SLE patients.