Objective: The aim of the study was to analyze the clinical features of elderly patients with coronavirus disease 2019 (COVID-19) and to explore the relationship between COVID-19 patients and kidney injury. Methods: A total of 188 elderly patients with confirmed COVID-19 enrolled in this study were hospitalized for at least 1 week in the Central Theater Command General Hospital of Chinese People's Liberation Army from January 3, 2020 to March 14, 2020. The recorded information included clinical data and results of kidney-related laboratory tests. Retrospective analysis was performed. Results: The median age of the patients was 69 years (interquartile range 65–78, range: 60–97 years); 31.4% were 60–74 years old, and 68.6% were over 75 years old. A total of 12.8% and 18.6% of the patients were in critical and severe stages of COVID-19, respectively. The proportions of patients using mechanical ventilators and deaths were 9.5% and 8.5%, respectively. A total of 26.1% and 8.5% of the patients showed mild elevation of blood urea nitrogen (BUN) and serum creatinine (SCr) levels at admission. A total of 18.6% and 5.9% of the patients had elevated BUN and SCr 1 week after admission, respectively. A total of 3.1% of the patients were diagnosed with acute kidney injury, and 75% of those patients had chronic kidney disease before admission. Compared with the patients aged 60–74 years, those over 75 years exhibited significantly increased proportions of elevated BUN levels, critical illness, use of mechanical ventilated, and death. Multivariate logistic regression analysis revealed that an elevated BUN level at admission and 1 week after admission were independent risk factors for death in the elderly patients with COVID-19. Conclusion: There were more critical cases and a high mortality in elderly patients with COVID-19. An increased BUN level was an independent risk factor for death in elderly patients with COVID-19.

Cell death and inflammation are important mechanisms in the induction of acute kidney injury (AKI) and the progression of chronic kidney disease. This focused review examines how the JUN amino terminal kinase (JNK) enzyme contributes to these pathologies. The JNK enzyme is activated in response to cellular stress, being most sensitive to oxidative stress. Biopsy studies have shown that JNK signaling is activated in human AKI and chronic kidney injury. Genetic and pharmacologic strategies have demonstrated a key role for JNK signaling in tubular cell death, inflammation, and loss of renal function in various animal models of AKI. This has been directly attributed to JNK1 signaling in the proximal tubular epithelial cells. JNK inhibition also reduces cell death, inflammation, and fibrosis in several models of progressive kidney disease; however, not all models show benefit with JNK blockade. JNK inhibitors are currently in clinical trials which opens the way for testing JNK-based therapy in selected types of renal injury. Some of the outstanding questions in this field include identifying the JNK1 target(s) in the induction of tubular cell necroptosis, and determining whether the pro-inflammatory actions of JNK signalling depend solely upon activation of JUN/Activator Protein-1.

Diabetic kidney disease (DKD), a major microvascular complication of diabetes mellitus, has become the second cause of end-stage renal disease enhancing the mortality rate of diabetes. However, there are still few treatment approaches to combat it. Traditional Chinese medicine (TCM) has been applied for a long time to treat DKD. However, there is a lack of research on how does TCM plays the role in treating DKD due to the complex of composition of TCM. In recent decade, gut microbiota is increasingly recognized for its contributions to host health, and the occurrence of gut–kidney axis also attracts many interests about microbiota in kidney injury. Some of the studies have already revealed that TCM can alleviate the symptoms of DKD through regulating gut microbiota and ameliorate a vicious circle caused by imbalance of gut–kidney axis. However, the problems of which specific species mediates the efficacy of TCM and how gut microbiota influences the process of DKD are urgent to solve. Therefore, this review systematically summarized the application of TCM and the importance of gut microbiota in DKD. More importantly, the review provided a new insight to find biomarkers for diagnosis and treatment of DKD. In future study, targeted manipulation of the gut microbiota will be progressively recognized as a way to enhance human health.

Evidence has been furnished that immune cells, and immune-podocytes interactions have increasingly become the focus of proteinuric kidney diseases, which affect millions of patients worldwide. Podocytes are highly specialized, terminally differentiated epithelial cells that wrap around the glomerulus to maintain the integrity of the glomerular filtration barrier. More recent studies demonstrate that podocytes express many elements of the innate and adaptive immune system including the complement components and receptors, through which podocytes can be involved in immune-mediated glomerular injuries and as a therapeutic target to alleviate the podocyte injury and progression to chronic kidney disease. The present review will shed light on recent findings, which have furthered our understanding of the immune mechanisms involved in podocyte injury, as well as the therapeutic implications in the treatment of immune-mediated glomerular injury.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has resulted in an ongoing worldwide pandemic since it was first recognized in December 2019. The kidney is one of the organs most easily affected by COVID-19. The injury of the kidney by COVID-19 manifested as hematuria, proteinuria, serum creatinine fluctuations, and even acute kidney injury (AKI). Critically ill patients with COVID-19 are much more prone to suffer from AKI. Moreover, AKI is related to poor outcomes in the patients infected with SARS-CoV-2. Therefore, early detection and active prevention of kidney injury are very important. In this article, we reviewed the epidemiology, clinical characteristics, pathogenesis, pathological manifestations, treatment, and prognosis of kidney injury in patients with COVID-19. It is expected to provide valuable insights for disease prevention and control from the perspective of nephrologists.