Kim Ki-Jo, Kim Ji-Young, Baek In-Woon, Kim Wan-Uk, Cho Chul-Soo
From the Division of Rheumatology, The Catholic University of Korea, Seoul, Republic of Korea.K-J. Kim, MD, Division of Rheumatology, St. Vincent Hospital, The Catholic University of Korea; J-Y. Kim, PhD, Institute of Bone and Joint Diseases, Catholic Research Institutes of Medical Sciences, The Catholic University of Korea; I-W. Baek, MD, Division of Rheumatology, Yeouido St. Mary's Hospital, The Catholic University of Korea; W-U. Kim, MD, PhD, Division of Rheumatology, Seoul St. Mary's Hospital, The Catholic University of Korea; C-S. Cho, MD, PhD, Division of Rheumatology, Yeouido St. Mary's Hospital, The Catholic University of Korea.
J Rheumatol. 2015 Feb;42(2):202-9. doi: 10.3899/jrheum.140568. Epub 2014 Dec 15.
Syndecan-1 (SDC-1) is a major constituent of the endothelial glycocalyx, which plays a role in maintaining vascular homeostasis and functions as a glomerular filtration barrier. SDC-1 is readily shed into the blood under various conditions, but the clinical implication of circulating SDC-1 in patients with systemic lupus erythematosus (SLE) remains unclear. We aimed to investigate the association of serum SDC-1 level with certain clinical manifestations of SLE.
We measured serum SDC-1 levels by ELISA in 111 patients with SLE, 18 with rheumatoid arthritis (RA), and 20 healthy subjects, and investigated its association with clinical manifestations and laboratory variables.
Serum SDC-1 levels were higher in patients with SLE than in those with RA and healthy controls (both p < 0.001) and were positively correlated with SLE Disease Activity Index (SLEDAI; r = 0.367, p < 0.001) and anti-dsDNA antibody level (r = 0.259, p = 0.007), but inversely correlated with serum C3 and CH50 levels (r = -0.305, p = 0.001 and r = -0.244, p = 0.012). Patients with active nephritis had higher serum SDC-1 levels than patients with inactive nephritis and those without nephritis (both p < 0.001). In addition, serum SDC-1 levels were correlated with renal SLEDAI score (r = 0.540, p < 0.001) and excretion of proteinuria as measured by spot urine protein/creatinine ratio (r = 0.538, p < 0.001). In 14 patients with lupus nephritis (LN) whose serum samples were obtained at the time of renal biopsy, there was a positive correlation between serum SDC-1 levels and activity index (r = 0.632, p = 0.015).
Serum SDC-1 levels are increased in SLE patients with nephritis, indicating that SDC-1 might be a useful serum biomarker for active LN.
Syndecan-1（SDC-1）是内皮糖萼的主要成分，在维持血管稳态中起作用，并作为肾小球滤过屏障发挥功能。在各种情况下，SDC-1很容易释放入血，但循环中的SDC-1在系统性红斑狼疮（SLE）患者中的临床意义仍不清楚。我们旨在研究血清SDC-1水平与SLE某些临床表现之间的关联。
我们通过酶联免疫吸附测定（ELISA）法测量了111例SLE患者、18例类风湿关节炎（RA）患者和20名健康受试者的血清SDC-1水平，并研究了其与临床表现和实验室指标的关联。
SLE患者的血清SDC-1水平高于RA患者和健康对照者（两者p均<0.001），且与SLE疾病活动指数（SLEDAI；r = 0.367，p <0.001）和抗双链DNA抗体水平呈正相关（r = 0.259，p = 0.007），但与血清C3和CH50水平呈负相关（r = -0.305，p = 0.001和r = -0.244，p = 0.012）。活动性肾炎患者的血清SDC-1水平高于非活动性肾炎患者和无肾炎患者（两者p均<0.001）。此外，血清SDC-1水平与肾脏SLEDAI评分（r = 0.540，p <0.001）以及通过随机尿蛋白/肌酐比值测量的蛋白尿排泄量相关（r = 0.538，p <0.001）。在14例肾活检时采集血清样本的狼疮性肾炎（LN）患者中，血清SDC-1水平与活动指数呈正相关（r = 0.632，p = 0.015）。
肾炎SLE患者的血清SDC-1水平升高，表明SDC-1可能是活动性LN的一种有用的血清生物标志物。
