Table 1.

The potential use of different biomarkers on FSGS diagnosis.

Biomarker	Species	Activity	Reference
Soluble urokinase-type plasminogen  activator receptor (SuPAR)	Human	Elevated levels in the plasma of primary FSGS patients and in plasma and urine of transplanted patients with recurrent FSGS	[23–25]
		Still inconclusive for primary FSGS diagnosis in children	[26]
	Mice	Causes foot process effacement, proteinuria, and FSGS-like glomerulopathy by direct activation of podocyte integrins	[16, 27]
Cardiotrophin-like cytokine  factor 1 (CLC-1 )	Human	Elevated plasma levels in patients with recurrent FSGS, mimicking the effects of FSGS plasma on Palb. Anti-CLC-1- specific monoclonal antibody blocks the Palb effect of active FSGS sera	[4, 13]
Transforming growth factor-beta  (TGF-β)	Human	Circulating plasma levels correlated with other biomarkers in patients with diverse glomerulopathies	[28]
		Increased renal expression in children with FSGS	[29]
		Increased expression of the protein, its receptor, and associated signalling proteins in podocytes of FSGS patients	[30]
		In situ expression is associated with changes in extracellular matrix and podocyte apoptosis	[31]
	Mice	Induces podocyte apoptosis	[32]
Malondialdehyde	Human	Potent marker of oxidative stress-induced lipid peroxidation used in several acute and chronic kidney diseases in adults and children	[33–35]
		Elevated urine and serum levels associated with glomerular overexpression in patients with FSGS	[36, 37]
	Mice	Associated with reactive oxygen species overproduction in animal glomeruli mimicking human FSGS	[38]
Dystroglycan	Human	Differential expression between MCD and FSGS patients	[39]
		Increased expression in FSGS compared to MDC renal biopsies	[40]
	Rat	Serves as matrix anchor to the glomerular filtration membrane	[41]
Transient receptor potential cation  channel 6 (TRP6)	Human	Fundamental component of the glomerular basement membrane. Gene mutations cause inherited glomerular diseases such as FSGS	[42, 43]
MicroRNAs  (miR-192 and miR-205)	Human	Higher serum levels in primary FSGS than MCD patients. They correlate with the degree of interstitial fibrosis in FSGS	[44]
	Rat	They are mainly expressed in the renal cortex	[45]
Metalloproteinases (MMP-2 and MMP-9) and Tissue inhibitors of metalloproteinases  (TIMPs)	Human	Elevated plasma levels associated with kidney allograft survival	[46]
		Circulating plasma levels correlated with other biomarkers in patients with diverse glomerulopathies	[28]
	Mice	Decreased expression in the kidneys of mice presenting glomerulonephritis	[47]
	Rat	Reduced expression was associated with fibronectin deposition in FSGS injured glomeruli	[48]
Human neutrophil gelatinase-associated  lipocalin (NGAL)	Human	Increase in urine and kidney cortical tubules of patients with acute renal failure	[49–51]
		Elevated levels in the urine from children with FSGS, presenting positive correlation with urinary protein excretion but negative correlation with estimated creatinine clearance at disease diagnosis	[52]