Proteinuria is a frequent finding among patients hospitalized with COVID-19, with a urine protein-creatinine ratio (UPCR) of 1 g/g or higher significantly associated with an increased risk for adverse kidney and patient outcomes, according to investigators.
In a single-center retrospective study of 200 patients admitted with COVID-19 to a tertiary care hospital in France, a UPCR of 1 g/g or higher, compared with lower values, at admission was significantly associated with approximately 4.8-, 3.0-, and 3.7-fold increased odds of requiring kidney replacement therapy (KRT), death during hospitalization, and admission to the intensive care unit (ICU), respectively, on multivariable analysis, Alexandre Karras, MD, of Hôpital Européen Georges Pompidou in Paris, and colleagues reported online in the Clinical Journal of the American Society of Nephrology.
In an unadjusted analysis, a UPCR of 1 g/g or higher was significantly associated with 3.6-fold increased odds of acute kidney injury (AKI), but the association lost significance on multivariable analysis.
Of the 200 patients, 84 (42%) had a UPCR of 1 g/g or higher at admission, although most patients had normal kidney function (median serum creatinine level of 0.94 mg/dL). Patients with a UPCR of 1 g/g or higher were older and more likely to have hypertension, according to the investigators.
In addition, on multivariable analysis, a urine retinol-binding protein to creatinine ratio greater than 0.03 mg/mmol was significantly associated with 5.2-, 15.5-, and 21-fold increased odds of AKI, ICU admission, and death, respectively, Dr Karras’ team reported.
The study population, which included 143 men and 57 women, had a median age of 63 years. All patients had proven infection with SARS-CoV-2, the novel coronavirus that causes COVID-19 and available laboratory proteinuria testing within 48 hours following admission.
During hospitalization, 118 patients (59%) were admitted to the ICU for severe COVID-19-related pneumonia. AKI was diagnosed in 88 patients (44%). KRT was required for 27 patients (13%). The authors noted that the low levels of albuminuria found in the study population suggest a predominant tubular origin of proteinuria, which was confirmed by elevated levels of urine retinol-binding protein.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Karras A, Livrozet M, Lazareth H, et al. Proteinuria and clinical outcomes in hospitalized COVID-19 patients. Published online February 23, 2021. Clin J Am Soc Nephrol. doi:10.2215/CJN.09130620