PB0063 - Antiphospholipid syndrome nephropathy is associated with severe clinical subsets and triple aPL positivity. A single-center retrospective study

Sunday, June 23, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

Ariela Hoxha, PhD, MSc

Assistant Professor
Internal Medicine Unit, Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy

Co-Author(s)

Nicola Perin, MD

Resident
Internal Medicine Unit, Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
ML

Marco Lovisotto

Resident
Internal Medicine Unit, Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
AC

Antonia Calligaro

Consultant
Rheumatology Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
Td

Teresa del Ross

Consultant
Rheumatology Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
MF

Maria Favaro

Consultant
Rheumatology Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
MT

Marta Tonello

Biologist
Rheumatology Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
MZ

Martina Zerbinati

Resident
Internal Medicine Unit, Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
AD

Andrea Doria

Head of Rheumatology Unit
Rheumatology Unit, Department of Medicine, University of Padua
Padua, Veneto, Italy
Paolo Simioni, MD, PhD

Head of Department of Medicine
University of Padova, Padova University Hospital
Padova, Veneto, Italy

Background: The prevalence of renal involvement in antiphospholipid antibody syndrome (APS) and its clinical and autoantibody features are poorly understood.

Aims: We evaluate the association with different laboratory and clinical APS subsets to identify risk factors for APS nephropathy.

Methods: We conducted a retrospective single-center cohort study. The medical records of 274 patients, 231 (84.3%) females, with a mean (±SD) age at diagnosis of 37.8 (±11.5) years, followed from 1990 to 2021, were reviewed. All the patients fulfill Sydney APS classification criteria. Renal involvement was defined as the presence of renal insufficiency (serum creatinine 1.4 mg/dl) and/or of urinary abnormalities (proteinuria 0.3 g/d with or without microscopic hematuria on two separate occasions, in the absence of urinary infection and or the presence of renal biopsy showing histopathologic lesions compatible with APS.

Results: Following a mean (±SD) follow-up of 208.4 (±91.7) months, a total of 36 (13.1%) APS nephropathy was recorded. APS nephropathy was found in 36/274 (13.1%) of primary APS patients; in 18/36 (50%) residual chronic renal failure and in 4/36 (11.1%) need renal transplantation. The prevalence of APS nephropathy was significantly higher in thrombosis/obstetric APS (TOAPS) and thrombotic APS (TAPS) alone compared to obstetric APS (OAPS) alone, p=0.0002 and p=0.0012, respectively. At the same time, there was no difference between TOAPS and TAPS. Patients with microangiopathy involvement presented a significantly higher rate of APS nephropathy than those without microangiopathy manifestations (45.5% vs 2.9%, p< 0.0001). Triple aPL positivity was significantly associated with APS nephropathy compared to single and double aPL positivity, respectively p< 0.0001 and p< 0.001.

Conclusion(s): APS nephropathy was associated with high morbidity. Higher risk clinical and/or autoantibody APS profiles, such as thrombosis and triple aPL positivity, could predict APS nephropathy. These findings should be considered when counseling APS patients and help guide clinicians' therapeutic decisions.