MO384ERYTHROCYTURIAAT ADMISSION IS A PREDICTOR OF ACUTE KIDNEY INJURY AND IN-HOSPITAL MORTALITY IN HOSPITALIZED PATIENTS WITH COVID-19
Authors: Khruleva Yulia , Troitskaya Elena , Efremovtseva Marina , Mubayazvamba Tapiwa , Kobalava Zhanna 
Published: May 2021

Abstract

Background and Aims
Acute kidney injury (AKI) is common among patients with coronavirus disease (COVID-19) and a major risk factor associated with mortality in hospitalized patients. Previously abnormal urine tests were reported to have a high incidence in COVID-19. We aimed to investigate the prevalence of urine tests changes and their impact on the outcomes in patients hospitalized with COVID-19.

Method
A retrospective analysis of the register of patients with COVID-19 was performed. COVID-19 was defined as the laboratory-confirmed infection and/or presence of the typical computer tomography (CT) picture with typical clinical signs. We excluded patients with re-hospitalizations, urinary tract infection, and single serum creatinine (SCr) measurement during hospitalization. Urine tests were performed within the first 24 h after hospitalization. Erythrocyturia was defined as the presence of &gt;3 red blood cells (RBC) per high-power field. Definition of acute kidney injury (AKI) was based on KDIGO criteria. Patients were identified as having in-hospital AKI, if AKI developed during hospitalization. P value &lt;0.05 was considered statistically significant.

Results
In final analysis we included 495 patients. Mean age was 64 [53;74], 51% (244) were males, mean Charlson index 3 [1;3], 66% with hypertension, 48% with obesity, 24% with diabetes mellitus (DM) and 6% with chronic kidney disease (CKD). 25% of patients were hospitalized in the intensive care unit (ICU), 17.8% (88) were treated with mechanical ventilation at some point during hospitalization. Patients were hospitalized on the 6±4 day of illness at mean. The mean length of stay was 11 [9;14] days, in the ICU - 4 [2;7] days. 19.4% patients died in hospital. The incidence of AKI was 22%, 47% patients had the 1st stage of AKI, 41% - the 2nd and 20% - the 3rd. In-hospital AKI was observed in 8.3% (41) of patients. Among discharged patients AKI was registered in 13%, of those who died in 60% (p&lt;0.0001).
52% (256) of patients had erythrocyturia and/or proteinuria and/or leukocyturia in urine test and admission: 35% of patients had proteinuria, 17% - hematuria and 19% - leukocyturia. The most prognostically significant associations of urinalysis changes were identified for erythrocyturia, which was present in 82 patients at admission, their mean RBC count in urine was 18.5 [7;52]. The presence of еrythrocyturia at admission was independent of age, gender, presence of hypertension, DM, obesity, blood test changes, pre-admission drug intake, included oral anticoagulants. Patients with erythrocyturia at admission had higher level of SCr at admission (101[83;140] vs 88[74;109] µmol/l, p=0.003), were more likely to develop AKI compared to patients without AKI (31.2% vs 12.4%, p&lt;0.001, respectively), had higher prevalence of in-hospital AKI (17% vs 6.5%, p=0.002) and more severe course of AKI (the 1st stage – 31% vs 54%, the 2nd - 43% vs 32%, the 3rd – 26% vs 14%, p=0.02). They also more often had CKD (13,4% vs 4.4%, p=0.001), more severe lung injury by CT scan during hospitalization (15.6% vs 5.5% with 75-90% lung injury, p=0.005, for the trend), were more frequently hospitalized in ICU (39% vs 22%, p=0.001), and had higher level of in-hospital mortality (32% vs 17%, p=0.002).
Erythrocyturia at admission was predictor for development of in-hospital AKI (odds ratio (OR) 2.94 with a 95% confidence interval (CI) of 1.35 to 6.15, p=0.002) and in-hospital mortality (OR 2.28, 95% CI of 1.28 to 3.97, p=0.002).

Conclusion
Erythrocyturia at admission is a common finding in hospitalized patients with COVID-19, and is associated with severity of disease and adverse outcomes in this population.