INTRODUCTION AND OBJECTIVE: The COVID-19 pandemic has resulted in 2.5 million deaths globally. Previous studies have suggested the virus may affect the kidneys, resulting in hematuria, proteinuria and acute kidney injury;however, the studies did not differentiate microscopic hematuria (MH) from gross hematuria (GH). In this study, we investigated the clinical outcomes and risk factors associated with GH compared to MH in COVID patients. METHODS: Following IRB approval, 250 consecutive medical records of COVID patients admitted to a tertiary care university hospital from 3/15/20 were analyzed. Patients without a urinalysis during the admission were excluded, the remaining 157 patients were included in the analysis. Patients were divided into three categories based on the presence of hematuria during the admission: none, microscopic hematuria (MH) and gross hematuria (GH). Outcomes including length of hospitalization, ICU admission, intubation, and lab values were compared amongst the categories. Chi-square test was used to compare the categorical variables, while ANOVA and t-test were used for the parametric variables. RESULTS: Of the 157 patients, 66 (42%) did not have hematuria, 36 (22.9%) had MH and 55 (35%) had GH. As seen in Fig.1, GH was associated with worse clinical outcomes such as higher intubation rate at 49.1%, compared to 27.8% in MH (p <0.05). In those with no hematuria, the intubation rate was 7.6%, significantly lower than patients with GH and MH (p <0.05). Mortality rate was also higher in those with GH compared to MH, at 30.9% and 22.2% respectively (p <0.05). Regarding kidney function, patients with GH, MH and no hematuria had acute kidney injury (AKI) at a rate of 67.3%, 58.3% and 39.4%, respectively (p <0.05). Peak C-reactive protein (CRP) values were higher in patients with GH and MH compared to those with no hematuria, at 24.04, 18.07 and 15.36, respectively (p <0.005). CONCLUSIONS: Gross hematuria was associated with poor kidney function, higher intubation rate and mortality compared to those with microscopic or no hematuria. Gross hematuria was linked to elevated biomarkers linked to inflammation and disease severity, such CRP and D-dimer, indicating possible direct effect of the virus on the kidneys. More studies are needed to further delineate the etiology behind hematuria in COVID patients.
Gross hematuria is associated with more severe disease and poorer clinical outcomes in covid-19 patients