title: Serum Renalase Levels Correlate with Disease Activity in Lupus Nephritis.
abstract: BACKGROUND
  Lupus nephritis (LN) is among the most serious complications of systemic lupus erythematosus (SLE), which causes significant morbidity and mortality. Renalase is a novel, kidney-secreted cytokine-like protein that promotes cell survival. Here, we aimed to investigate the relationship of serum renalase levels with LN and its role in the disease progression of LN.
  
  
  METHODS
  For this cross-sectional study, 67 LN patients and 35 healthy controls were enrolled. Seventeen active LN patients who received standard therapies were followed up for six months. Disease activity was determined by the SLE Disease Activity-2000 (SLEDAI-2K) scoring system and serum renalase amounts were determined by ELISA. Predictive value of renalase for disease activity was assessed. Furthermore, the expression of renalase in the kidneys of patients and macrophage infiltration was assessed by immunohistochemistry.
  
  
  RESULTS
  Serum renalase amounts were significantly higher in LN patients than in healthy controls. Moreover, patients with proliferative LN had more elevated serum renalase levels than Class V LN patients. In proliferative LN patients, serum renalase levels were significantly higher in patients with active LN than those with inactive LN. Serum renalase levels were positively correlated with SLEDAI-2K, 24-h urine protein excretion, ds-DNA and ESR but inversely correlated with serum albumin and C3. Renalase amounts decreased significantly after six-months of standard therapy. The performance of renalase as a marker for diagnosis of active LN was 0.906 with a cutoff value of 66.67 μg/ml. We also observed that the amount of renalase was significantly higher in glomerular of proliferative LN along with the co-expression of macrophages.
  
  
  CONCLUSIONS
  Serum renalase levels were correlated with disease activity in LN. Serum renalase might serve as a potential indicator for disease activity in LN. The marked increase of glomerular renalase and its association with macrophages suggest that it might play an important role in disease progression of LN.
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Chaojun
authors.initials: C
authors.lastname: Qi
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Minfang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Xinghua
authors.initials: X
authors.lastname: Shao
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Xinbei
authors.initials: X
authors.lastname: Chang
authors.affiliation: Health Care Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Zhuping
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Health Care Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Cao
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Mou
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Medicine, Veterans Affairs Connecticut Healthcare System, Yale University, New Haven, Connecticut, United States of America.
authors.forename: Gary
authors.initials: G
authors.lastname: Desir
authors.affiliation: Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Ni
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000097:blood*
chemical_list: D015415:Biomarkers; D008995:Monoamine Oxidase; C521557:renalase