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

Significance Statement Some cases of COVID-19 pneumonia have presented with kidney injury, and autopsy findings for patients with COVID-19 have revealed renal involvement. In this retrospective, single-center study of Chinese patients with COVID-19 pneumonia, 251 of 333 patients (75.4%) presented with renal complications, including proteinuria, hematuria, and AKI. After the median duration of 12 days of follow-up, nearly half of patients with AKI recovered from AKI within 3 weeks of onset of infection. However, patients with renal involvement had higher overall mortality (11.2%) compared with patients without renal involvement (1.2%). Adverse short-term outcomes of renal involvement were associated with severity of COVID-19 pneumonia. These findings indicate that although early renal abnormalities often resolve in such patients, intensive support and careful monitoring of severe or critical illness is appropriate for COVID-19 pneumonia with renal complications. Background Some patients with COVID-19 pneumonia also present with kidney injury, and autopsy findings of patients who died from the illness sometimes show renal damage. However, little is known about the clinical characteristics of kidney-related complications, including hematuria, proteinuria, and AKI. Methods In this retrospective, single-center study in China, we analyzed data from electronic medical records of 333 hospitalized patients with COVID-19 pneumonia, including information about clinical, laboratory, radiologic, and other characteristics, as well as information about renal outcomes. Results We found that 251 of the 333 patients (75.4%) had abnormal urine dipstick tests or AKI. Of 198 patients with renal involvement for the median duration of 12 days, 118 (59.6%) experienced remission of pneumonia during this period, and 111 of 162 (68.5%) patients experienced remission of proteinuria. Among 35 patients who developed AKI (with AKI identified by criteria expanded somewhat beyond the 2012 Kidney Disease: Improving Global Outcomes definition), 16 (45.7%) experienced complete recovery of kidney function. We suspect that most AKI cases were intrinsic AKI. Patients with renal involvement had higher overall mortality compared with those without renal involvement (28 of 251 [11.2%] versus one of 82 [1.2%], respectively). Stepwise multivariate binary logistic regression analyses showed that severity of pneumonia was the risk factor most commonly associated with lower odds of proteinuric or hematuric remission and recovery from AKI. Conclusions Renal abnormalities occurred in the majority of patients with COVID-19 pneumonia. Although proteinuria, hematuria, and AKI often resolved in such patients within 3 weeks after the onset of symptoms, renal complications in COVID-19 were associated with higher mortality.