Urinary Neutrophil Gelatinase-Associated Lipocalin Does Not Distinguish Acute Rejection from Other Causes of Acute Kidney Injury in Pediatric Renal Transplant Recipients

The use of diagnostic tools for pediatric AKI: applying the current evidence to the bedside

Given the known deleterious consequences of acute kidney injury (AKI), exciting recent research efforts have focused on developing strategies for the earlier recognition of AKI in the pediatric population. Recognizing the limitations of serum creatinine, investigators have focused on the study of novel biomarkers and practical bedside tools for identifying patients at risk for AKI prior to a rise in serum creatinine. In PubMed, there are presently over 30 original research papers exploring the use of pediatric AKI risk prediction tools in just the last 2 years. The following review highlights the most recent advances in the literature regarding opportunities to refine our ability to detect AKI early. Importantly, this review discusses how prediction tools including novel urine and serum biomarkers, practical risk stratification tests, renal functional reserve, and electronic medical record alerts may ultimately be applied to routine clinical practice.

Investigation of new biomarkers of kidney injury in renal transplant recipients undergoing graft biopsy

AIM

Urinary and blood kidney biomarkers (BM) remain insufficient for early kidney injury detection. We aimed to compare new kidney BM with histopathological data in kidney allograft recipients.

METHODS

Blood and urine samples were collected from consecutive adult patients just before graft biopsy. All kidney samples were classified according to the Banff 2007 classification. The diagnostic performance of 16 new BM was compared to those of urinary proteins, blood urea nitrogen, eGFR, and serum creatinine to identify histopathological groups.

RESULTS

Two hundred and twenty-three patients were analyzed. Microalbuminuria and urinary proteins performed well to discriminate glomerular injury from slightly modified renal parenchyma (SMRP). Urinary neutrophil gelatinase-associated lipocalin (NGAL) had the best performance relative to SMRP (AUROC .93) for acute tubular necrosis (ATN) diagnosis. Other BM had a slightly lower AUROC (.89). For the comparison of ATN to acute rejection, several new urinary BM (NGAL, cystatin C, MCP1) and classical BM (eGFR, serum creatinine) gave similar AUROC values (from .80 to .85). Urinary NGAL values in patients with ATN were 10-time higher than those with acute rejection (P=.0004).

CONCLUSION

The new BM did not outperform classical BM in the context of renal transplantation. Urinary NGAL may be useful for distinguishing between ATN and acute rejection.

Urinary Biomarkers for Diagnosis and Prediction of Acute Kidney Allograft Rejection: A Systematic Review

Noninvasive tools for diagnosis or prediction of acute kidney allograft rejection have been extensively investigated in recent years. Biochemical and molecular analyses of blood and urine provide a liquid biopsy that could offer new possibilities for rejection prevention, monitoring, and therefore, treatment. Nevertheless, these tools are not yet available for routine use in clinical practice. In this systematic review, MEDLINE was searched for articles assessing urinary biomarkers for diagnosis or prediction of kidney allograft acute rejection published in the last five years (from 1 January 2015 to 31 May 2020). This review follows the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Articles providing targeted or unbiased urine sample analysis for the diagnosis or prediction of both acute cellular and antibody-mediated kidney allograft rejection were included, analyzed, and graded for methodological quality with a particular focus on study design and diagnostic test accuracy measures. Urinary C-X-C motif chemokine ligands were the most promising and frequently studied biomarkers. The combination of precise diagnostic reference in training sets with accurate validation in real-life cohorts provided the most relevant results and exciting groundwork for future studies.