Early Predictors of AKI in COVID-19 Patients

There is a high risk of acute kidney injury (AKI) in patients with COVID-19. Patients with COVID-19-related AKI commonly require renal replacement therapy (RRT). In several clinical settings, serum cystatin C (sCysC) and serum neutrophil gelatinase-associated lipocalin (sNGAL) have been observed to be superior to serum creatinine (sCr) as biomarkers for kidney injury. Further, elevated sCysC is associated with disease severity and mortality in COVID-19.

Naomi Pode Shakked, MD, PhD, and colleagues conducted an analysis to examine the utility of sCysC and sNGAL as predictors of COVID-19-associated AKI, the need for RRT, and the need for admission to the intensive care unit (ICU) when measured at presentation to the emergency department. Results were reported online in Clinical Biochemistry [doi.org/10.1016/j.clinbiochem.2022.01.006].

The study included 52 patients who presented to the ED with laboratory-confirmed COVID-19. The primary outcome of interest was development of COVID-19-associated AKI; secondary outcomes were the need for RRT and admission to the ICU.

Among the 52 patients, 42.3% (n=22) developed AKI and 36.4% (8/22) of those patients required RRT. Both sCr and sCysC demonstrated excellent performance for predicting AKI (area under the curve [AUC] 0.86 and 0.87, respectively), and the need for RRT (AUC, 0.94 and 0.95, respectively). Acceptable performance was seen with sNGAL for predicting AKI (AUC, 0.81) and need for RT (AUC, 0.87).

In summary, the authors said, “SCr and sCysC measured at ED presentation are both highly accurate predictors of AKI and need for RRT, whereas sNGAL demonstrated adequate diagnostic performance. While sCysC was previously shown to be superior to sCr as a diagnostic biomarker of kidney injury in certain etiologies, our findings demonstrate that sCr is comparable to sCysC in the context of predicting COVID-19-associated AKI. Given the high sensitivity of these biomarkers for predicting the need for RRT, and as sCysC is associated with mortality in COVID-19 patients, we recommend their measurement for enabling risk stratification and early intervention.”