PB1509 - Antiphosphatidylserine/prothrombin antibodies in obstetric antiphospholipid syndrome: a case-control study

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

AV

Arne Vandevelde, PharmD (he/him/his)

PhD Student
Coagulation Laboratory, Ghent University Hospital, Gent, Belgium
Gent, Oost-Vlaanderen, Belgium

Co-Author(s)

Jean-Christophe R. Gris, MD, PhD

Professor
Department of Hematology, CHU Nîmes, Univ Montpellier, Nîmes, France
Nimes, Languedoc-Roussillon, France
Gary W. Moore, DBMS

Professor
Department of Haematology, Specialist Haemostasis Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
London, England, United Kingdom
JM

Jacek Musiał

Professor
Department of Internal Medicine, Jagiellonian University Medical College, Kraków, Poland
Kraków, Malopolskie, Poland
Stéphane Zuily, MD

Professor
Université de Lorraine, Inserm, DCAC and Centre Hospitalier Regional Universitaire de Nancy, Vascular Medicine Division and Regional Competence Center for Rare Vascular and Systemic Autoimmune Diseases, Nancy, France
Nancy, Lorraine, France
DW

Denis Wahl

Professor
Université de Lorraine, Inserm, DCAC and Centre Hospitalier Regional Universitaire de Nancy, Vascular Medicine Division and Regional Competence Center for Rare Vascular and Systemic Autoimmune Diseases, Nancy, France
Nancy, Lorraine, France
Katrien M. J Devreese, MD, PhD (she/her/hers)

Professor
Coagulation Laboratory, Ghent University Hospital, Gent, Belgium
Ghent, Oost-Vlaanderen, Belgium

Background: The diagnostic value of antiphosphatidylserine/prothrombin antibodies (aPS/PT) for evaluation of obstetric antiphospholipid syndrome (OAPS) is unclear.

Aims: Evaluating the role of aPS/PT in OAPS.

Methods: A multicentric case-control study including OAPS patients and controls was performed. Lupus anticoagulant (LAC), anticardiolipin antibodies (aCL) IgG/IgM, anti-β2-glycoprotein I antibodies (aβ2GPI) IgG/IgM, and aPS/PT IgG/IgM were determined. Positivity rate, interval-specific likelihood ratios (LRs), and age-adjusted odds ratios (ORs) including 95% confidence interval (95%CI) were calculated with additional multivariable logistic regression analyses. Fisher’s exact and Mann-Whitney U test were applied (p < 0.05 significant). The study was approved by the medical ethics committee.

Results: 84 OAPS patients (without thrombosis) and 426 controls were included. Controls included non-APS women with autoimmune diseases (n=137), routine antiphospholipid antibody testing (n=168), and normal (n=98) or complicated (n=23) pregnancy history. The obstetric history of OAPS patients included prematurity < 34th week (n=5), ≥3 early ( < 10th week) pregnancy losses (PLs) (n=56), ≥1 late (≥10th week) PL (n=22), and both early and late PLs (n=1). aPS/PT IgG, IgM, and IgG and/or IgM were positive in 40.5%, 32.1%, and 53.6% of OAPS patients, and in 15.3%, 14.8%, and 25.6% of controls, respectively. ORs were 4.32 (95%CI: 2.54-7.36), 3.37 (95%CI: 1.93-5.89), and 4.22 (95%CI: 2.54-7.00), respectively. ORs for aPS/PT IgG, IgM, or IgG/IgM were not significantly higher than one when adjusting for LAC. Adjusting for aCL and aβ2GPI, only aPS/PT IgG remained significantly associated with OAPS (OR 2.04, 95%CI: 1.11-3.75). LRs did not increase with higher positive aPS/PT IgG/IgM values (Table 1). aPS/PT was more prevalent (p < 0.05) in patients with early compared to late PLs (39.3% and 86.4%, respectively) and with higher median titers (Figure 1).

Conclusion(s): aPS/PT IgG and IgM were associated with OAPS diagnosis, but without added value compared to LAC. Higher aPS/PT titers and positivity rate was found in OAPS patients with late PL.