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.

Regulated necrosis has been reported to exert an important role in the pathogenesis of various diseases, including renal ischemia-reperfusion (I/R) injury. Damage to renal tubular epithelial cells and subsequent cell death initiate the progression of acute kidney injury (AKI) and subsequent chronic kidney disease (CKD). We found that ferroptosis appeared in tubular epithelial cells (TECs) of various human kidney diseases and the upregulation of tubular proferroptotic gene ACSL4 was correlated with renal function in patients with acute kidney tubular injury. XJB-5-131, which showed high affinity for TECs, attenuated I/R-induced renal injury and inflammation in mice by specifically inhibiting ferroptosis rather than necroptosis and pyroptosis. Single-cell RNA sequencing (scRNA-seq) indicated that ferroptosis-related genes were mainly expressed in tubular epithelial cells after I/R injury, while few necroptosis- and pyroptosis-associated genes were identified to express in this cluster of cell. Taken together, ferroptosis plays an important role in renal tubular injury and the inhibition of ferroptosis by XJB-5-131 is a promising therapeutic strategy for protection against renal tubular cell injury in kidney diseases.

Background: Information on kidney impairment in patients with coronavirus disease 2019 (COVID-19) is limited. This study aims to assess the prevalence and impact of abnormal urine analysis and kidney dysfunction in hospitalized COVID-19 patients in Wuhan. Methods: We conducted a consecutive cohort study of COVID-19 patients admitted in a tertiary teaching hospital with 3 branches following a major outbreak in Wuhan in 2020. Hematuria, proteinuria, serum creatinine concentration and other clinical parameters were extracted from the electronic hospitalization databases and laboratory databases. Incidence rate for acute kidney injury (AKI) was examined during the study period. Association between kidney impairment and in-hospital death was analyzed. Results: We included 710 consecutive COVID-19 patients, 89 (12.3%) of whom died in hospital. The median age of the patients was 63 years (inter quartile range, 51-71), including 374 men and 336 women. On admission, 44% of patients have proteinuria hematuria and 26.9% have hematuria, and the prevalence of elevated serum creatinine and blood urea nitrogen were 15.5% and 14.1% respectively. During the study period, AKI occurred in 3.2% patients. Kaplan–Meier analysis demonstrated that patients with kidney impairment have higher risk for in-hospital death. Cox proportional hazard regression confirmed that elevated serum creatinine, elevated urea nitrogen, AKI, proteinuria and hematuria was an independent risk factor for in-hospital death after adjusting for age, sex, disease severity, leukocyte count and lymphocyte count. Conclusions: The prevalence of kidney impairment (hematuria, proteinuria and kidney dysfunction) in hospitalized COVID-19 patients was high. After adjustment for confounders, kidney impairment indicators were associated with higher risk of in-hospital death. Clinicians should increase their awareness of kidney impairment in hospitalized COVID-19 patients.

Adipose-derived mesenchymal stem cells employed exosomes to attenuate AKI-CKD transition through tubular epithelial cell dependent Sox9 activation Adipose-derived mesenchymal stem cells employed exosomes to attenuate AKI-CKD transition through tubular epithelial cell dependent Sox9 activation

Summary Background and objectives Previous studies have identified inflammatory features that enable the prediction of renal outcome of IgA nephropathy (IgAN); however, validation of these findings is still needed. This prospective study was performed to determine the characteristics of renal interstitial infiltration and tertiary lymphoid organ (TLO) neogenesis in a cohort of Chinese patients with IgAN. Design, setting, participants, & measurements Adult patients with IgAN were recruited into this study from June 2009 to June 2010. Inflammatory cells in renal biopsy tissues were detected by immunohistochemistry and immunofluorescence. Correlations between the density of interstitial inflammatory cells, grades of TLOs, and clinicopathologic features were evaluated. Of 152 eligible patients, 72 (47%) were successfully followed-up by telephone at 30 months after renal biopsy. Twelve patients were classified as the severe group and 60 patients were classified as the stable group, according to the progression of serum creatinine levels during the follow-up period. A comparison of the severity of interstitial infiltration and the frequency of TLO neogenesis between the two groups was performed. Results The accumulation of interstitial inflammatory cells was correlated with decreased renal function, heavy proteinuria, and severe glomerular, interstitial, and arterial lesions in patients with IgAN. TLOs, identified as nodular inflammatory infiltrates containing organized DC-SIGN⁺, CD4⁺, CD8⁺, and CD20⁺ cells, were observed in 37.5% of patients. Patients with high-grade TLOs exhibited a high percentage of mesangial hypercellularity and crescents as well as severe interstitial and arterial lesions. Patients in the severe group exhibited more severe interstitial infiltration and a higher percentage of TLO neogenesis (83.3% versus 33.3%; P=0.001) compared with patients in the stable group. Conclusions As contributors to an active local inflammatory response, the severity of interstitial infiltration and the frequency of TLO neogenesis are correlated with glomerular, interstitial, and arterial lesions as well as IgAN progression.