Large cohort studies suggest that high convective volumes associated with online hemodiafiltration may reduce the risk of mortality/morbidity compared to optimal high-flux hemodialysis. By contrast, intradialytic tolerance is not well studied. The aim of the FRENCHIE (French Convective versus Hemodialysis in Elderly) study was to compare high-flux hemodialysis and online hemodiafiltration in terms of intradialytic tolerance. In this prospective, open-label randomized controlled trial, 381 elderly chronic hemodialysis patients (over age 65) were randomly assigned in a one-to-one ratio to either high-flux hemodialysis or online hemodiafiltration. The primary outcome was intradialytic tolerance (day 30-day 120). Secondary outcomes included health-related quality of life, cardiovascular risk biomarkers, morbidity, and mortality. During the observational period for intradialytic tolerance, 85% and 84% of patients in high-flux hemodialysis and online hemodiafiltration arms, respectively, experienced at least one adverse event without significant difference between groups. As exploratory analysis, intradialytic tolerance was also studied, considering the sessions as a statistical unit according to treatment actually received. Over a total of 11,981 sessions, 2,935 were complicated by the occurrence of at least one adverse event, with a significantly lower occurrence in online hemodiafiltration with fewer episodes of intradialytic symptomatic hypotension and muscle cramps. By contrast, health-related quality of life, morbidity, and mortality were not different in both groups. An improvement in the control of metabolic bone disease biomarkers and β2-microglobulin level without change in serum albumin concentration was observed with online hemodiafiltration. Thus, overall outcomes favor online hemodiafiltration over high-flux hemodialysis in the elderly.

The aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed.

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in the medullary thick ascending limb of Henle (MTALH) contributes to NaCl balance and is also responsible for the creation of medullary interstitial hypertonicity. Despite the presence of angiotensin II subtype 1 (AT1) receptors in both the luminal and the basolateral plasma membranes of MTALH cells, no information is available on the effect of angiotensin II on NaCl reabsorption in MTALH and, furthermore, on angiotensin II-dependent medullary interstitial osmolality. MTALHs from male Sprague-Dawley rats were isolated and microperfused in vitro; transepithelial net chloride absorption (JCl) as well as transepithelial voltage (V te) were measured. Luminal or peritubular 10 Ϫ11 and 10 Ϫ10 M angiotensin II had no effect on JCl or V te. However, 10 Ϫ8 M luminal or peritubular angiotensin II reversibly decreased both J Cl and Vte. The effect of both luminal and peritubular angiotensin II was prevented by the presence of losartan (10 Ϫ6 M). By contrast, PD-23319, an AT 2-receptor antagonist, did not alter the inhibitory effect of 10 Ϫ8 M angiotensin II. Finally, no additive effect of luminal and peritubular angiotensin II was observed. We conclude that both luminal and peritubular angiotensin II inhibit NaCl absorption in the MTALH via AT1 receptors. Because of intrarenal angiotensin II synthesis, angiotensin II concentration in medullary tubular and interstitial fluids may be similar in vivo to the concentration that displays an inhibitory effect on NaCl reabsorption under the present experimental conditions. in vitro microperfusion; renal tubule; NaCl transport; angiotensin II subtype 1; losartan ANGIOTENSIN II IS A POTENT regulator of extracellular fluid volume, mainly through its direct effects on renal tubular sodium reabsorption, as well as on aldosterone synthesis. Acute systemic infusion of low-dose angiotensin II stimulates overall tubular sodium reabsorption and decreases urine sodium excretion, independently of changes in renal or systemic hemodynamics (5, 15). In rat experiments using in vivo superficial tubule microperfusion, systemic angiotensin II infusion at 20 ng⅐kg Ϫ1 ⅐min Ϫ1 , which achieves a subpressor, physiological plasma concentration (picomolar range), stimulates proximal water and NaCl reabsorption (24). Conversely, saralazin infusion, which suppresses endogenous angiotensin II activity, inhibits proximal tubule absorption (24). In addition, endogenously produced angiotensin II is responsible for a nanomolar intratubular angiotensin II concentration that stimulates proximal sodium reabsorption (33). In the more distal part of the nephron, angiotensin II also directly stimulates sodium reabsorption by activating Na ϩ /H ϩ exchange and the amiloridesensitive Na ϩ channel (2, 23, 37). Finally, angiotensin II stimulates aldosterone synthesis and thereby indirectly enhances sodium reabsorption via the epithelial sodium channel in the cortical collecting duct (26) and likely via the thiazidesensitive sodium-chloride cotransporter in the distal convoluted tubule (21).In the loop of Henle, available...

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