Prevalence, risk factors and prognostic significance of acute renal injury in hospitalized patients with COVID-19: a retrospective cohort study

Aim

To evaluate the prevalence, risk factors and prognostic significance of acute kidney injury (AKI) in the Russian cohort of hospitalised patients with COVID-19.

Material and methods

We enrolled 1280 consecutive hospitalized patients with COVID-19 in a retrospective study. Diagnosis of COVID-19 was verified by PCR and/or typical CT findings. Changes in serum creatinine were evaluated during hospitalisation to diagnose AKI according to KDIGO criteria. Factors associated with development of AKI and its prognostic significance were studied using multiple regression models.

Results

Mild to moderate proteinuria (0.3 to 3 g/L) was found in 648 (50.6%) patients with COVID-19, hematuria in 77 (6.0%) patients, and leucocyturia in 282 (22.0%) patients. After admission, AKI occurred in 371 (28.9%) patients. Most of them presented with mild increase in serum creatinine, whereas only 10 (2.7%) patients required treatment with hemodialysis. Independent risk factors for AKI included age over 65 years, elevated inflammatory biomarkers (C-reactive protein and ferritin), D-dimer and ACTT. 162 (12.7%) of 1280 patients with COVID-19 died in the hospital. AKI was associated with a higher risk of death (hazards ratio of 3.96, 95% confidence interval 2.83-5.54).

Conclusion

AKI frequently occurred in hospitalized patients with COVID-19 and was associated with a higher risk of death. Inflammatory response and thrombosis contribute significantly to AKI in patients with COVID-19.

Key words

COVID-19, acute kidney injury, inflammatory biomarkers, D-dimer.