Table 1.
Review of the described studies
| Ref. | Event | Urinary markers | n | Endpoints |
| Li et al[21] | AR | Perforin, GRB | n = 151 | Potential to predict AR |
| Yannaraki et al[22] | AR | Perforin, GRB and Fas-L | n = 162 | Levels are increased in different clinical settings (AR, UTI, CMVi or CMVd, CAN, DGF) |
| Heng et al[23] | AR | GRB and Perforin | n = 680 | Combined use of GRB and Perforin may lead to a better prediction of AR |
| Muthukumar et al[31] | AR | FOX-3mRNA | n = 83 | Reversal of acute AR and lower risk of graft failure with high levels of FOXP3 mRNA |
| Aquino-Dias et al[35] | AR with DGF | Perforin, GRB, PI-9, Fas-L and Foxp-3 mRNA | n = 48 | Urinary Foxp-3 with 100% sensitivity and 100% specificity for AR |
| Schaub et al[39] | Subclinical tubulitis | CXCL9/CXCL10, a-microglobulin/Cr, NGAL/Cr | n = 88 | CXCL9/CXCL10 potential noninvasive biomarkers for subclinical tubulitis |
| Matz et al[40] | AR and prediction of short and long-term graft function | IP-10 mRNA and protein | n = 76 for IP-10 mRNA | Incidence of AR: Urinary IP-10 protein observed 2/3 d prior to biopsy with 71% sensitivity and 95% specificity |
| n = 100 for IP-10 protein | Long term graft function: Urinary IP-10 predictive of GFR at 6 mo post-transplant | |||
| Ho et al[41] | Subclinical and clinical tubulitis | CXCL10:Cr | n = 102 | CXCL10:Cr sensitivity of 73.3% and specificity of 72.7% |
| Jackson et al[42] | AR | CXCL9/CXCL10 | n = 110 adults and 46 children | Elevated CXCL9/CXCL10 identified AR and BKI |
| Hricik et al[43] | CTOT-1: AR | Urinary protein and mRNACXCL9/CXCL10, GRB mRNA | n = 2095 | CXCL9 protein with high NPV 92% |
| CXCL9 detects subclinical tubulitis | ||||
| Stratification of patients with low vs high risk for future injury | ||||
| Utility of CXCL9 for ruling out acute rejection | ||||
| Suthanthiran et al[44] | AR | Urinary mRNA based signatures | n = 4300 | Three-gene signature of CXCL10 mRNA, 18S ribosomal RNA, CD3ε mRNA distinguish ACR from AMR and even from other etiologies of graft dysfunction |
| Matignon et al[45] | ACR vs AMR | Urinary mRNA based signatures | n = 84 | mRNAs for CD3ε, CD105, CD14, CD46 and 18S rRNA may be able to differentiate between ACR and AMR |
| Lorenzen et al[48] | AR | miRNAs: miR-10a, -10b, -210 | n = 88 | Low Urinary miR-210 during AR |
| Urinary miR-210 predict outcome of renal transplant | ||||
| Urinary miR-210 novel biomarker of AR |
GRB: Granzyme B; PI-9: Proteinase inhibitor-9; NGAL: Urine neutrophil gelatinase-associated lipocalin; Cr: Creatinine; DGF: Delayed graft function; AR: Acute rejection; UTI: Urinary tract infection; CAN: Chronic allograft nehropathy; CTOT-1: Clinical trial of transplantation-1; IP-10: Interferon-g–inducible protein-10; BKI: Polyomavirus BK infection; ACR: Acute cellular rejection; AMR: Antibody mediated rejection; Fas-L: Fas-Fas ligand lytic pathway.