Biomarkers in acute kidney injury: On the cusp of a new era?
Mark Canney, … , Edward G. Clark, Swapnil Hiremath
Mark Canney, … , Edward G. Clark, Swapnil Hiremath
Published July 3, 2023
Citation Information: J Clin Invest. 2023;133(13):e171431. https://doi.org/10.1172/JCI171431.
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Commentary

Biomarkers in acute kidney injury: On the cusp of a new era?

Abstract

The field of nephrology has been slow in moving beyond the utilization of creatinine as an indicator for chronic kidney disease and acute kidney injury (AKI). Early diagnosis and establishment of etiology, in particular, are important for treatment of AKI. In the setting of hospital-acquired AKI, tubular injury is more common, but acute interstitial nephritis (AIN) has a more treatable etiology. However, it is likely that AIN is under- or misdiagnosed due to current strategies that largely rely on clinical gestalt. In this issue of the JCI, Moledina and colleagues made an elegant case for the chemokine called C-X-C motif ligand 9 (CXCL9) as a biomarker of AIN. The authors used urine proteomics and tissue transcriptomics in patients with and without AIN to identify CXCL9 as a promising, noninvasive, diagnostic biomarker of AIN. These results have clinical implications that should catalyze future research and clinical trials in this space.

Authors

Mark Canney, Edward G. Clark, Swapnil Hiremath

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Figure 1

A framework that incorporates testing for urinary CXCL9 may improve the accuracy of diagnosis and management of AKI.

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A framework that incorporates testing for urinary CXCL9 may improve the ...
Clinicians rely on kidney biopsies under the current approach to diagnose AIN. However, if the biopsy is contraindicated, the risk for over or under treatment remains high. If the biopsy is performed, accuracy of diagnosis is accompanied by a higher frequency of biopsy-related complications. Use of biomarker testing beyond biopsy may improve the accuracy of diagnosis while mitigating risk for complications. Analysis of urinary CXCL9 alongside creatinine could establish a diagnostic strategy that decreases the risk of false positive and false negative diagnosis. Moledina et al. (8) established cut points for urinary CXCL9-to-creatinine ratios, in which values above 58.9 ng/g ruled in AIN, while those below 14.2 ng/g suggested another cause for AKI. This approach may indicate causes of AKI at early time points when prevention of further kidney damage is possible.