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Renal Involvement and Early Prognosis in Patients with COVID-19 Pneumonia

Our take —

This study showed that renal injury was common among patients hospitalized for COVID-19 in hospital in Wuhan, China, particularly for those with severe or critical pneumonia, and was associated with mortality. The fact that the majority of patients developed AKI during hospitalization is evidence of worsening kidney function over time, and warrants close renal monitoring of hospitalized COVID-19 patients. Both mechanistic studies and multi-center prospective cohort studies with longer follow-up times are needed to better understand renal involvement in COVID-19 disease.

Study design

Case Series; Retrospective Cohort

Study population and setting

This study included 333 of 467 patients admitted at Tongji Hospital in Wuhan, China from January 28 to February 9, 2020 for COVID-19 pneumonia. Patients were included if they had at least one urine dipstick measurement on the morning after admission or a diagnosis of Acute Kidney Injury (AKI) during hospitalization. Those with a history of chronic kidney disease in the 3 months prior to admission were excluded. Patients were followed up to February 23, 2020.

Summary of Main Findings

The median age of the patients was 56 years; 55% were male. Overall, 75% had renal involvement on admission, including 66% and 42% with proteinuria and hematuria, respectively. Based on KIDGO criteria, 4.7% (22/467) of the total number of patients had AKI. Only 3 patients had AKI at admission; the majority (19/22) developed during the course of hospitalization, and a high proportion 19/22 (86.4%) died. Four of these 22 patients (18%) completely recovered from AKI with a mean recovery time of 6 days.

Study Strengths

The study collected important clinical and laboratory variables for the majority of patients and renal measurements were repeated over time.

Limitations

The study was conducted in one referral hospital in China among patients with moderate to critical COVID-19 pneumonia, potentially limiting the generalizability of its findings. Additionally, not all patients had renal measurements performed on admission, suggesting differential assessment of patients which might have led to selection bias and an overestimation of renal injury. Interpretation of the results should consider the multiple statistical comparisons and the extremely wide confidence intervals in the regression results.

Value added

This study was among the first to assess renal involvement among patients hospitalized for COVID-19 pneumonia. It provided limited evidence of a high burden of renal injury and its correlation with COVID-19 severity and mortality.

This review was posted on: 22 July 2020