Background/Purpose: To identify independent clinical and laboratory risk factors associated with antiphospholipid syndrome-associated nephropathy (APSN) and highlight the clinical importance of early screening in high-risk patients.

Methods: This retrospective cohort study included patients with antiphospholipid syndrome (APS) consecutively enrolled in the APS-Shanghai database between January 2021 and March 2025. All patients were classified based on the 2023 ACR/EULAR criteria. Biopsy-confirmed APSN was used as the diagnostic endpoint. Clinical and laboratory data were extracted from the electronic medical record system. Differences between APSN and non-APSN groups were analyzed, and multivariate logistic regression was performed to identify independent risk factors. All statistical analyses were conducted using SPSS version 29.0.

Results: Among 208 APS patients included, 32 (15.4%) were diagnosed with biopsy-confirmed APSN. Compared with patients without renal involvement, those with APSN had a significantly higher prevalence of hypertension, valvular heart disease, thrombocytopenia, ischemic stroke, and cerebrovascular stenosis. Laboratory differences included higher serum creatinine, lower estimated glomerular filtration rate (eGFR), reduced complement C3 levels, and a higher positivity rate for IgA anti-cardiolipin antibodies. Multivariate logistic regression identified three independent clinical predictors of APSN: valvular heart disease (OR = 2.720, 95% CI: 1.049–7.055, P = 0.04), thrombocytopenia (OR = 3.664, 95% CI: 1.601–8.386, P = 0.002), and stroke (OR = 3.948, 95% CI: 1.673–9.313, P = 0.002). These findings suggested that APS patients with these features are at increased risk of developing APSN and may benefit from early screening, including renal function monitoring and consideration for renal biopsy, even in the absence of overt renal symptoms.

Conclusion: This study identified valvular heart disease, thrombocytopenia, and stroke as independent risk factors for APSN. These findings underscore the importance of vigilant renal evaluation in APS patients with systemic vascular involvement and support the role of renal biopsy in clarifying occult nephropathy in high-risk individuals.

Figure 1. Study flowchart.

Table 1 Demographic and clinical characteristics at baseline in Antiphospholipid Syndrome (APS) patients

Table 2 Possible risk factors for developing APSN among APS patients.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/risk-factors-for-antiphospholipid-syndrome-associated-nephropathy-a-retrospective-cohort-analysis/