Table 1.
Biomarkers and their functional status and pathophysiology
| Marker | Functional Status | Pathophysiology |
|---|---|---|
| IL-1α | Inflammation | Pro inflammatory cytokine involved in the malfunction, injury, and local inflammation of renal cells41,42 |
| IL-1β | Inflammation/Ischemia |
Pro inflammatory cytokine involved in the malfunction, injury, and local inflammation of renal cells25,41 IL-1β is generated by the injured epithelial proximal tubular cell and is an important mediator of endothelial ischemic injury43 |
| IL-2 | Inflammation | Pro inflammatory cytokine IL-2 is elevated in haemodialysis patients with uremic pruritus44 |
| IL-4 | Inflammation | Anti-inflammatory cytokine elevated in end stage renal disease45 |
| IL-6 | Inflammation/Ischemia |
Pro inflammatory cytokine involved in orchestration of the inflammatory response following acute renal insult46. Renal IL-6 expression in renal tubular epithelial cells is significantly increased in the pathogenesis of AKI47 IL-6 is generated by injured epithelial proximal tubular cells and is an important mediator of endothelial ischemic injury43 |
| IL-8 | Inflammation | IL-8 is generated by injured epithelial proximal tubular cells and is an important mediator of endothelial ischemic injury43 |
| IL-10 | Inflammation | IL-10 is an anti-inflammatory cytokine involved in the regulation and maintenance of normal renal function48 |
| VEGF | Inflammation | Pro inflammatory growth factor involved in angiogenesis42 |
| EGF | Mitogen | Intrarenal EGF expression is decreased in tubular injury; decreased urine EGF excretion is a marker for CKD progression49 |
| TNFα | Inflammation | Pro inflammatory cytokine associated with renal disease42 |
| IFNγ | Activator of macrophages | Cytokine involved in the pathophysiology of CKD50 |
| MCP-1 | Inflammation | Pro inflammatory cytokine involved in the pathogenesis of CKD42 |
| IGF-1 | Growth factor | Serum IGF-1 levels are positively associated with CKD51 |
| Eotaxin | Inflammation | Inflammatory marker, the chemokine eotaxin, is a predictor of the incidence of renal failure52. |
| IL-1Ra | Inflammation/Ischemia | Anti-inflammatory cytokine involved in renal ischemic reperfusion injury53 |
| PDGF-BB | Growth factor | Growth factor involved in driving renal fibrosis; independent of underlying kidney disease54 |
| IP-10 | Chemokine | Serum IP-10 is a marker for underlying renal disease55 |
| IL-12p40 | Inflammation | IL-12p40 is a key pro inflammatory cytokine involved in crescentic glomerulonephritis56 |
| sIL2Ra | Inflammation | Inflammatory modulator involved in the progression of interstitial fibrosis in CKD57 |
| sIL6R | Inflammation | Pro inflammatory cytokine which is elevated in patients with CKD58 |
| sTNFR1 | Inflammation | sTNFR1 is associated with kidney disease progression59 |
| sTNFR2 | Inflammation | sTNFR2 is a marker for kidney tissue damage60 |
| MMP9 | Inflammation | MMP9 increases the expression of TGF-β1 and promotes the occurrence of renal interstitial fibrosis61 |
| NGAL | Ischemia | NGAL is a non-invasive urinary biomarker for renal ischemia14 |
| CRP | Inflammation | Marker of inflammation in AKI62,63 |
| D-Dimer | Inflammation | D-Dimer levels are elevated in renal insufficiency64. |
| NSE | Enzyme | NSE is elevated in patients who present with kidney disease65 |
| H-FABP | Ischemia | H-FABP is a marker for detection of ischaemic injury33 |
| MK | Ischemia | After ischaemic reperfusion, MK is up-regulated in the proximal tubules. The absence of MK protects against renal ischaemic reperfusion injury by reducing the infiltration of leukocytes38 |
IL, interleukin; AKI, acute kidney disease; CKD, chronic kidney disease; VEGF, vascular endothelial growth factor; EGF, epidermal growth factor; TNFα, tumour necrosis factor alpha; IFNγ, interferon gamma; MCP, monocyte chemoattractant protein; IGF, insulin-like growth factor; IL-1Ra, interleukin-1 receptor antagonist; PDGF-BB, platelet-derived growth factor beta homodimer; IP-10, interferon gamma-induced protein 10; IL-12p40, interleukin-12 subunit p40; sIL2Ra, soluble interleukin-2 receptor alpha; sIL6R, soluble interleukin 6 receptor; sTNFR1, soluble tumour necrosis factor receptor-1; sTNFR2, soluble tumour necrosis factor receptor-2; MMP9, matrix metallopeptidase 9; TGFβ1, transforming growth factor beta 1; NGAL, neutrophil gelatinase-associated lipocalin; CRP, C-reactive protein; NSE, neuron-specific enolase; H-FABP, heart-type fatty acid-binding protein; MK, midkine.