title: Elevated serum levels of syndecan-1 are associated with renal involvement in patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  Serum SDC-1 levels are increased in SLE patients with nephritis, indicating that SDC-1 might be a useful serum biomarker for active LN.
authors.affiliation: 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.
authors.forename: Ki-Jo
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: 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.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: 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.
authors.forename: In-Woon
authors.initials: IW
authors.lastname: Baek
authors.affiliation: 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.
authors.forename: Wan-Uk
authors.initials: WU
authors.lastname: Kim
authors.affiliation: 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. chocs@catholic.ac.kr.
authors.forename: Chul-Soo
authors.initials: CS
authors.lastname: Cho
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D053668:Syndecan-1 / Q000097:blood*
chemical_list: D015415:Biomarkers; D053668:Syndecan-1
keywords: LUPUS NEPHRITIS; SYNDECAN-1; SYSTEMIC LUPUS ERYTHEMATOSUS