Table 4.

Renal biomarkers of diabetic kidney injury[21,43]

Biomarkers
Traditional biomarkers	Traditional biomarkers of glomerular injury	Albumin/creatinine ratio eGFR	Lack of specificity and sensitivity	(1) Predict the late stages of DKD; (2) Daily variation in urine albumin/creatinine ratio; and (3) eGFR values may be affected by the patient’s hemodynamics, diet and hydration status
Novel biomarkers	Glomerular biomarkers	NF-α, transferrin, Type IV collagen, L-PGDS, IgG, ceruloplasmin, laminin, GAGs, fibronectin, podocalyxin, VEGF	Appear before microalbuminuria	Early predictor of DKD
	Tubular biomarkers	α-1-microglobulin CysC; KIM-1; NGAL; nephrin; NAG; L-FABP; VDBP; CypA; s-Klotho	Appear before/precede microalbuminuria	(1) Are more sensitive vs new glomerular biomarkers; (2) Early predictors of DKD; and (3) Predictor of DKD progression
	Biomarkers of inflammation	Cytokines: TNF-α, IL-1β, IL-18, interferon gamma-IP-10, MCP-1, adiponectin, G-CSF, eotaxins, RANTES or CCL-5, orosomucoid	(1) Precede a significantly increased albuminuria; (2) Correlate positively with albumin excretion rate and intima-media thickness; and (3) May trigger direct renal injury	Predictor of DKD progression
	Biomarkers of oxidative stress	Urinary 8oHdG Pentosidine		Predict the development of DKD

L-PGDS: Lipocalin-type prostaglandin D synthase; IgG: Immunoglobulin G; GAGs: Glycosaminoglycans; CysC: Cystatin C; KIM-1: Kidney injury molecule 1; 8oHdG: 8-oxo-7,8-dihydro-2-deoxyguanosine; RANTES: Regulated on activation, normal T cell expressed and secreted; G-CSF: Granulocyte colony-stimulating factor; MCP-1: Monocyte chemoattractant protein 1; IP-10: Induced protein-10; TNF-α: Tumor necrosis factor α; IL: Interleukin; CypA: Cyclophilin A; VDBP: Vitamin D-binding protein; L-FABP: Liver-type fatty-acid binding protein; NAG: N-acetyl-β-D-glucosaminidase; NGAL: Neutrophil gelatinase-associated lipocalin; DKD: Diabetic kidney disease; eGFR: Estimated glomerular filtration rate; VEGF: Vascular endothelial growth factor; CCL-5: Chemokine ligand 5T.