Obstructive nephropathy

Obstructive uropathy (OU) is a common condition in the elderly, particularly in men due to prostate disease. Besides the reversible effects of acute urinary tract obstruction on kidney function, with reduction of renal blood flow (RBF), glomerular filtration rate (GFR) and a tubular dysfunction, chronic obstruction can additionally cause permanent kidney injury. In this context, prolonged and untreated OU results in obstructive nephropathy (ON). ON is a nonspecific tubulointerstitial nephropathy, which can lead to chronic kidney disease (CKD) and to end-stage renal disease (ESRD). ON is one of the leading causes of ESRD in the elderly. Experimental ON models ureteral obstruction-mediated kidney injury and helps unravel key processes of the CKD pathogenesis. Apart from reversing obstruction, treatment strategies of ON consist of selective targeting on molecular mechanisms implicated in apoptosis, inflammation, and renal fibrosis. © 2019 Elsevier Inc. All rights reserved

Pathogenesis and management of intradialytic hypertension

Hypertension is common in chronic kidney disease patients especially in those undergoing hemodialysis (HD). Usually, blood pressure falls after the HD session but in some patients a paradoxical increase has been observed during or immediately after HD. This phenomenon is referred as intradialytic hypertension. HD patients with intradialytic hypertension or increased blood pressure during HD present higher cardiovascular (CV) morbidity and mortality rates. The underlying mechanism of intradialytic hypertension is multifactorial. Activation both of renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system, volume and sodium overload with concomitant increase in cardiac output, and endothelial dysfunction have been implicated in the pathogenesis of intradialytic hypertension. Given the lack of clinical trials regarding the pathophysiology and management of intradialytic hypertension, current treatment strategies are based mainly on experts’ opinion. The purpose of this review is to describe the pathophysiology of intradialytic hypertension and discuss current strategies in order to improve intradialytic blood pressure management and concomitant HD patients’ outcomes. © 2014 Bentham Science Publishers

Alterations in gut immunological barrier in SARS-CoV-2 infection and their prognostic potential

Although coronavirus disease 2019 (COVID-19) is primarily associated with mild respiratory symptoms, a subset of patients may develop more complicated disease with systemic complications and multiple organ injury. The gastrointestinal tract may be directly infected by SARS-CoV-2 or secondarily affected by viremia and the release of inflammatory mediators that cause viral entry from the respiratory epithelium. Impaired intestinal barrier function in SARS-CoV-2 infection is a key factor leading to excessive microbial and endotoxin translocation, which triggers a strong systemic immune response and leads to the development of viral sepsis syndrome with severe sequelae. Multiple components of the gut immune system are affected, resulting in a diminished or dysfunctional gut immunological barrier. Antiviral peptides, inflammatory mediators, immune cell chemotaxis, and secretory immunoglobulins are important parameters that are negatively affected in SARS-CoV-2 infection. Mucosal CD4+ and CD8+ T cells, Th17 cells, neutrophils, dendritic cells, and macrophages are activated, and the number of regulatory T cells decreases, promoting an overactivated immune response with increased expression of type I and III interferons and other proinflammatory cytokines. The changes in the immunologic barrier could be promoted in part by a dysbiotic gut microbiota, through commensal-derived signals and metabolites. On the other hand, the proinflammatory intestinal environment could further compromise the integrity of the intestinal epithelium by promoting enterocyte apoptosis and disruption of tight junctions. This review summarizes the changes in the gut immunological barrier during SARS-CoV-2 infection and their prognostic potential