Antiphospholipid Antibody Positivity and the Clinical Outcomes of Patients with Systemic Lupus Erythematosus

Objective To identify the prevalence of antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE) patients and determine the relationship between aPL and the clinical outcomes. Methods SLE patients with aPL test results within 2 years of enrollment were selected from Korean lupus network study. They were classified into two groups: aPL (+) group, patients positive for at least one aPL, and aPL (−) group, patients without an aPL. The clinical characteristics of the two groups were compared and the role of aPL in the risk of chronic kidney disease (CKD) in SLE patients was examined. Results Among the 469 SLE patients, 69 (14.7%) had at least one aPL. The prevalence of cerebrovascular disease and CKD was higher in the aPL (+) group than in the aPL (−) group (10.1% vs. 1.8% and 13.8% vs. 5.1%, p＜0.05). Multivariable regression analysis showed that the aPL positivity (odds ratio=3.93, 95% confidence interval=1.48∼10.47) was associated with the risk of CKD after adjusting for age, disease duration, and lupus nephritis history. Conclusion The prevalence of aPL in Korean SLE patients is 14.7%, and it is associated with a higher prevalence of cerebrovascular disease and CKD in SLE patients. The aPL positivity is independently associated with the risk of CKD in SLE patients.