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Kidney Week

Abstract: PO0618

Serum Lysyl Oxidase Is a Potential Diagnostic Biomarker for Kidney Fibrosis

Session Information

  • CKD Mechanisms - 1
    October 22, 2020 | Location: On-Demand
    Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

  • 2103 CKD (Non-Dialysis): Mechanisms


  • Zhang, Xiaoqin, Department of Nephrology, Tongji Hospital, Tongji University, Shanghai, China, Shanghai, China
  • Yu, Chen, Department of Nephrology, Tongji Hospital, Tongji University, Shanghai, China, Shanghai, China

Kidney fibrosis is the ultimate consequence of advanced stages of chronic kidney disease (CKD); however, there are currently no reliable biomarkers or noninvasive diagnostic tests available for the detection of kidney fibrosis. Lysyl oxidase (LOX) promotes collagen crosslinking, and serum LOX levels have been shown to be elevated in patients with fibrosis of the heart, lungs and liver. However, serum LOX levels have not been reported in patients with kidney fibrosis. We explored whether serum LOX levels are associated with kidney fibrosis.


Overall, 202 patients with kidney disease underwent renal biopsy, scoring of kidney fibrosis and determination of the area of kidney fibrosis. LOX levels were measured in serum and in kidney tissues. We analyzed the association of circulating LOX and tissue LOX levels with the scores and areas of kidney fibrosis. LOX expression was also investigated with in vitro and in vivo kidney fibrosis models.


Serum LOX levels were higher in patients with kidney fibrosis than in those without kidney fibrosis (p<0.001) and higher in patients with moderate-severe kidney fibrosis than in patients with mild kidney fibrosis (p<0.001). Both serum LOX and renal tissue LOX levels correlated with the area of kidney fibrosis (r=0.748, p<0.001; r=0.899, p<0.001, respectively). ROC curve analysis of serum LOX levels showed an AUC of 0.80 (95% CI: 0.74 to 0.86). The optimal serum LOX level cutoff point was 253.34 ρg/ml for the prediction of kidney fibrosis and 306.56 ρg/ml for the prediction of moderate-severe renal fibrosis. LOX expression levels were significantly upregulated (2.3-2.6-fold and 6-fold, respectively) in in vitro and in vivo interstitial fibrosis models.


Both serum LOX and tissue LOX levels correlated with the presence and degree of kidney fibrosis in patients with CKD. These results suggest that serum LOX levels could potentially serve as a noninvasive diagnostic biomarker for kidney fibrosis and may further potentially serve as a stratified biomarker for the identification of mild and moderate-severe kidney fibrosis.


  • Government Support - Non-U.S.