Acute kidney injury (AKI) is common in patients hospitalized with COVID-19 and urinary biomarkers at admission may predict its development and prognosis, according to an ongoing, prospective single-center study.

At a median 4 days after hospital admission, stage 1 AKI developed in 12 (52.2%) of 23 patients included in the study, Faeq Husain-Syed, MD, of University Hospital Giessen and Marburg in Germany, and colleagues reported in Nephrology Dialysis Transplantation. Ten of the 12 cases received treatment in an intensive care unit.

At a median of 10 days post-admission, 1 of the 5 patients whose AKI did not resolve progressed from stage 1 to stage 2, and 4 progressed from stage 1 to stage 3. Three patients required renal replacement therapy (RRT) but died, according to the investigators.

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Patients in whom AKI developed had lower renal function compared with those who did not experience AKI. Of the 23 patients, 19 (82.6%) had increased proteinuria independent of subsequent AKI. Proteinuria was greater in AKI compared with non-AKI patients (442.0 vs 142.0 mg/g creatinine). All patients had an elevated renal resistance index on admission.

The study revealed that proteinuria and ɑ1-microglobulin excretion at admission were greater among patients who experienced AKI compared with those who did not. The median ɑ1-microglobulin excretion was higher among AKI patients who experienced progression of AKI stage compared with those who did not (87.2 vs 34.1 mg/g creatinine). Median proteinuria levels, however, did not differ between AKI progressors and AKI non-progressors (442.3 vs 459.9 mg/g creatinine).

Among the patients with AKI, those who progressed from stage 1 to stage 2 or 3 had higher levels of urinary tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7), which have been identified as novel biomarkers for predicting moderate to severe AKI.

According to the investigators, ɑ1-microglobulin excretion and TIMP-2 and IGFBP7 on admission appear to improve risk stratification for severe outcomes (stage 3 AKI, RRT, and death). They pointed out, however, that the number of patients who reached those outcomes was quite small.


Husain-Syed F, Wilhem J, Kassoumeh S, et al. Acute kidney injury and urinary biomarkers in hospitalized patients with coronavirus disease 2019 [published online July 20, 2020]. Nephrol Dial Transplant. doi: 10.1093/ndt/gfaa162