Altered kidney function and acute kidney damage markers predict survival outcomes of COVID-19 patients: A prospective pilot study

Abstract

BackgroundThe central role in the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), called as coronavirus disease 2019 (COVID-19), infection is attributed to angiotensin-converting enzyme 2 (ACE-2). ACE-2 expressing respiratory system involvement is the main clinical manifestation of the infection. However, literature about the association between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and higher ACE-2 expressing kidney is very limited. In this study, we primarily aimed to investigate whether there is a kidney injury during the course of SARS-CoV-2 infection. The predictive value of kidney injury for survival was also determined.MethodsA total of 47 participants who met the inclusion criteria were included in the study. The participants were classified as ‘‘COVID-19 patients before treatment’’ ‘‘COVID-19 patients after treatment’’, ‘‘COVID-19 patients under treatment in ICU’’ and ‘‘controls’’. The parameters comorbidity, serum creatinine and cystatin C levels, CKD-EPI eGFR levels, KIM-1 and NGAL levels, urine KIM-1/creatinine and NGAL/creatinine ratios were statistically compared between the groups. The associations between covariates including kidney disease indicators and death from COVID-19 were examined using Cox proportional hazard regression analysis.ResultsSerum creatinine and cystatin C levels, urine KIM-1/creatinine levels, and CKD-EPI, CKD-EPI cystatin C and CKD-EPI creatinine-cystatin C eGFR levels exhibited significant difference in the groups. The causes of the difference were more altered kidney function and increased acute kidney damage in COVID-19 patients before treatment and under treatment in ICU. Additionally, incidences of comorbidity and proteinuria in the urine analysis were higher in the COVID-19 patients under treatment in ICU group. Urine KIM-1/creatinine ratio and proteinuria were associated with COVID-19 specific death.ConclusionsWe found that COVID-19 patients under treatment in ICU exhibited extremely higher levels of serum cystatin C, and urine KIM-1/creatinine and urine NGAL/creatinine ratios. These results clearly described the acute kidney damage by COVID-19 using molecular kidney damage markers for the first time in the literature. Lowered CKD-EPI, CKD-EPI cystatin C and CKD-EPI creatinine-cystatin C eGFR levels were determined in them, as well. Urine KIM-1/creatinine ratio and proteinuria were associated with COVID-19 specific death. In this regard, considering kidney function and kidney damage markers must not be ignored in the COVID-19 patients, and serial monitoring of them should be considered.