Department of Rheumatology and Immunology, University of Szeged, Szeged, Hungary.
Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary.
Biomarkers. 2021 Jul;26(5):443-449. doi: 10.1080/1354750X.2021.1910343. Epub 2021 Apr 19.
There is a lack of non-invasive biomarkers to identify lupus nephritis (LN). Soluble urokinase plasminogen activator receptor (suPAR) is a sensitive biomarker of ongoing inflammation and a potential marker of podocyte dysfunction. The aim of this study was to assess urine and plasma suPAR in LN. 14 systemic lupus erythematosus (SLE) patients with newly diagnosed LN, 8 active SLE patients (SLEDAI >8) without LN and 31 healthy individuals were enrolled. Urine and plasma samples were taken before the initiation of LN induction therapy, and monthly thereafter. Global and renal disease activity were defined using the SLEDAI-2K and the SLEDAI-2K renal domain score, respectively. suPAR concentrations were measured with the suPARnostic Flex ELISA assay. Urine and plasma suPAR levels were elevated in SLE patients with active LN compared with resolved LN and healthy controls. Urine suPAR levels were comparable to healthy controls in active SLE without LN. Urine and plasma suPAR levels were higher before than after the initiation of LN induction therapy. Prospective follow-up measurements also suggested that urine suPAR levels raised again in patients with a relapse of LN according to SLEDAI-2K renal domain score, whereas plasma suPAR levels did not correlate with renal disease activity. Urine suPAR is a promising LN activity biomarker, given its isolated elevation in urine in active LN and pronounced decrease with LN improvement.
目前缺乏用于识别狼疮肾炎 (LN) 的非侵入性生物标志物。可溶性尿激酶型纤溶酶原激活物受体 (suPAR) 是一种敏感的炎症标志物，也是足细胞功能障碍的潜在标志物。本研究旨在评估 LN 中的尿液和血浆 suPAR。纳入了 14 名新诊断为 LN 的系统性红斑狼疮 (SLE) 患者、8 名无 LN 的活动期 SLE 患者（SLEDAI>8）和 31 名健康个体。在开始 LN 诱导治疗之前和之后每月采集尿液和血浆样本。使用 SLEDAI-2K 和 SLEDAI-2K 肾脏域评分分别定义整体和肾脏疾病活动度。使用 suPARnostic Flex ELISA 测定法测量 suPAR 浓度。与缓解期 LN 和健康对照组相比，活动期 LN 的 SLE 患者尿液和血浆 suPAR 水平升高。无 LN 的活动期 SLE 患者的尿液 suPAR 水平与健康对照组相当。与开始 LN 诱导治疗前相比，治疗后尿液和血浆 suPAR 水平降低。前瞻性随访测量还表明，根据 SLEDAI-2K 肾脏域评分，LN 复发的患者尿液 suPAR 水平再次升高，而血浆 suPAR 水平与肾脏疾病活动度无关。尿液 suPAR 是一种有前途的 LN 活动生物标志物，因为它在活动期 LN 中单独在尿液中升高，并且随着 LN 改善而明显降低。
