AUTHOR=Rostami Zohreh , Mastrangelo Giuseppe , Einollahi Behzad , Nemati Eghlim , Shafiee Sepehr , Ebrahimi Mehrdad , Javanbakht Mohammad , Saadat Seyed Hassan , Amini Manouchehr , Einollahi Zahra , Beyram Bentolhoda , Cegolon Luca 

TITLE=A Prospective Study on Risk Factors for Acute Kidney Injury and All-Cause Mortality in Hospitalized COVID-19 Patients From Tehran (Iran)

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.874426

DOI=10.3389/fimmu.2022.874426

ISSN=1664-3224

ABSTRACT=Background. Several reports suggested that acute kidney injury (AKI) is a relatively common occurrence in hospitalized COVID-19 patients but its prevalence is inconsistently reported across different populations. Moreover, it is unknown whether AKI results from a direct infection of the kidney by SARS-CoV-2 or it is a consequence of the physiologic disturbances and therapies used to treat COVID-19. We aimed to estimate the prevalence of acute kidney injury (AKI) since it varies by geographical settings, time periods and populations studied; and to investigate whether clinical information and laboratory findings collected at hospital admission might influence AKI incidence (and mortality) in a particular point in time during hospitalization for COVID-19.
Methods. Herein we conducted a prospective longitudinal study investigating the prevalence of AKI and associated factors in 997 COVID-19 patients admitted to Baqiyatollah general hospital of Tehran (Iran), collecting both clinical information and several dates (of: birth; hospital admission; AKI onset; ICU admission; hospital discharge; death). In order to examine how the clinical factors influenced AKI incidence and all-cause mortality during hospitalization, survival analysis using the Cox proportional-hazards models was adopted. Two separate multiple Cox regression models were fitted for each outcome (AKI and death). 
Results. In this group of hospitalized COVID1-19 patients, prevalence of AKI was 28.5% and the mortality rate was 19.3%. AKI incidence was significantly enhanced by diabetes, hyper-kalemia, higher levels of WBC count and blood urea nitrogen (BUN). COVID-19 patients more likely to die over the course of their hospitalization were those presenting a joint association between ICU admission with either severe COVID-19 or even moderate COVID-19, hypo-kalemia, higher level of BUN, WBC and LDH measured at hospital admission. Diabetes and comorbidities did not increase the mortality risk among these hospitalized COVID-19 patients.
Conclusions. Since the majority of patients developed AKI after ICU referral and 40% of them were admitted to ICU within 2 days since hospital admission, these patients may have been already in critical clinical conditions at admission, even though affected by mild/moderate form of COVID-19, suggesting the need of early monitoring these patients for the onset of eventual systemic complications.