PB0959 - Adjusted Global Antiphospholipid Syndrome Score (aGAPSS) Loses its Predictive Accuracy for Thrombosis Recurrence During Follow-up in Thrombotic Primary Antiphospholipid Syndrome

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

PG

Pedro Gaspar, MD

Internal Medicine Department, Hospital Santa Maria, ULS Santa Maria, Lisbon, Portugal
Póvoa De Santa Iria, Lisboa, Portugal

Co-Author(s)

AC

Ana Rita Cruz-Machado

MD
Rheumatology and Metabolic Bone Diseases Department, ULS Santa Maria, Lisbon, Portugal
Lisboa, Lisboa, Portugal
FR

Filipa Ribeiro

PhD
Instituto de Medicina Molecular João Lobo Antunes, Centro Académico de Medicina de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
Lisbon, Lisboa, Portugal
VR

Válter R. Fonseca

MD, PhD
Instituto de Medicina Molecular João Lobo Antunes, Centro Académico de Medicina de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
Lisbon, Lisboa, Portugal
SS

Savino Sciascia

Physician
University Center of Excellence on Nephrologic, Rheumatologic and Rare Diseases (ERK-Net, ERN-ReConnect and RITA-ERN Member) with Nephrology and Dialysis Unit and Center of Immuno-Rheumatology and Rare Diseases (CMID), Department of Clinical and Biological Sciences, ASL Città Di Torino and University of Turin, Turin, Italy
Turin, Piemonte, Italy
LG

Luis Graca

Professor
Instituto de Medicina Molecular João Lobo Antunes, Centro Académico de Medicina de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
Lisbon, Lisboa, Portugal
VC

Vasco C. Romão

MD, PhD
Rheumatology and Metabolic Bone Diseases Department, ULS Santa Maria, Lisbon, Portugal
Lisbon, Lisboa, Portugal

Background: How changes in the adjusted Global Antiphospholipid Syndrome Score (aGAPSS) over time influences its ability to predict recurrent thrombosis is poorly studied in primary APS (pAPS).

Aims: To assess the accuracy of the aGAPSS at diagnosis vs. follow-up in predicting thrombotic recurrence.

Methods: Retrospective study including 92 patients with thrombotic pAPS. Data were collected at diagnosis and until the last visit, and the aGAPSS was calculated. Recurrent events occurred during antithrombotic therapy. Using receiver operating characteristic (ROC) curves and areas under the curve (AUC), we calculated the optimal cut-off of aGAPSS-diagnosis that predicted recurrence risk and explored the risk factors for thrombosis recurrence.

Results: Most were women (57.6%; mean [SD]: age, 50.4 [12.1] years; disease duration, 8.9 [7.0] years; type of presenting event: arterial, 51.3%). Recurrence affected 23 (25.0%) patients after a mean of 4.7 (4.8) years. Comparing disease onset to the last visit, lupus anticoagulant (LA) (p < 0.001) and anticardiolipin (ACL) (p=0.033) positivity decreased, unlike ß2-glycoprotein (ß2GPI) (p=0.216) and triple antiphospholipid antibody (aPL) positivity (p=0.848). Disease duration, presenting thrombosis (arterial), and persistent ß2GPI, ACL and triple positivity were associated with recurrence (Table 1). Triple positivity remained associated with recurrence in multivariate analysis (p=0.009). The aGAPSS decreased over time (Fig. 1A) and was higher in patients with recurrent thrombosis at diagnosis and follow-up (Fig. 1B-C). The AUC showed that aGAPSS-diagnosis had a better diagnostic accuracy compared to aGAPSS-follow-up (Fig. 1D). Using ROC analysis, aGAPSS-diagnosis ≥7 showed the maximal AUC and was strongly associated with recurrence (p=0.001), even after adjusting (p=0.001). The same cut-off for aGAPSS-follow-up underperformed (Fig. 1E) and was not independently associated with recurrent thrombosis (p=0.072) (Table 1).

Conclusion(s): aGAPSS-diagnosis ≥7 predicts recurrence in thrombotic pAPS with good accuracy. The loss of predictive power of aGAPSS-follow-up relies on aPL seronegativization. aPL persistence may serve as a more reliable predictor of recurrent thrombosis.