Acute kidney injury (AKI) and Chronic Kidney Disease (CKD) are global health problems. The pathophysiology of acute-on-chronic kidney disease (AoCKD) is not well understood. We aimed to study clinical outcomes in patients with previous normal (pure acute kidney injury; P-AKI) or impaired kidney function (AoCKD) across the 2012 Kidney Disease Improving Global Outcomes (KDIGO) AKI classification. We performed a retrospective study of patients with AKI, divided into P-AKI and AoCKD groups, evaluating clinical and epidemiological features, distribution across KDIGO-2012 criteria, in-hospital mortality and need for dialysis. One thousand, two hundred and sixty-nine subjects were included. AoCKD individuals were older and had higher comorbidity. P-AKI individuals fulfilled more often the serum creatinine (SCr) ≥ 3.0× criterion in AKI-Stage3, AoCKD subjects reached SCr ≥ 4.0 mg/dL criterion more frequently. AKI severity was associated with in-hospital mortality independently of baseline renal function. AoCKD subjects presented higher mortality when fulfilling AKI-Stage1 criteria or SCr ≥ 3.0× criterion within AKI-Stage3. The relationship between mortality and associated risk factors, such as the net increase of SCr or AoCKD status, fluctuated depending on AKI stage and stage criteria sub-strata. AoCKD patients that fulfil SCr increment rate criteria may be exposed to more severe insults, possibly explaining the higher mortality. AoCKD may constitute a unique clinical syndrome. Adequate staging criteria may help prompt diagnosis and administration of appropriate therapy.

Membranoproliferative glomerulonephritis (MPGN) represents a histologic pattern of glomerular injury that may be due to several aetiologies. Few studies have comprehensively analysed the recurrence of MPGN according to the current classification system. We collected a multicentre, retrospective cohort of 220 kidney graft recipients with biopsy-proven native kidney disease due to MPGN between 1981 and 2021 in 11 hospitals. Demographic, clinical and histologic parameters of prognostic interest were collected. The main outcomes were time to kidney failure, time to recurrence of MPGN and disease remission after recurrence. The study group included 34 complement-mediated and 186 immune complex–mediated MPGN. A total of 81 patients (37%) reached kidney failure in a median follow-up of 79 months. The main predictors of this event were the development of rejection episodes and disease recurrence. In all, 54 patients (25%) had a disease recurrence in a median of 16 months after kidney transplantation. The incidence of recurrence was higher in patients with dysproteinaemia (67%) and complement-mediated MPGN (62%). In the multivariable model, complement-mediated MPGN emerged as a predictor of recurrence. A total of 33 patients reached kidney failure after recurrence. The main determinants of no remission were early time to recurrence (<15 months), estimated glomerular filtration rate <30 mL/min/1.73 m² and serum albumin <3.5 g/dL at the time of recurrence. One-fourth of the patients with native kidney disease due to MPGN developed clinical recurrence in the allograft, especially in cases with complement-mediated disease or in those associated with dysproteinaemia. The kidney outcomes of disease recurrence with currently available therapies are heterogeneous and thus more effective and individualized therapies are needed.

Hypoglycemia is a serious complication following the administration of insulin for hyperkalemia. We determined the incidence of hypoglycemia and severe hypoglycemia (blood glucose <70 or ≤40 mg/dl, respectively) in a cohort of AKI and non-dialysis dependent CKD patients who received an intravenous infusion of insulin plus glucose to treat hyperkalemia. We retrospectively reviewed charts of all AKI and non-dialysis dependent CKD patients who received 10 U of insulin plus 50 g glucose to treat hyperkalemia from December 1, 2013 to May 31, 2015 at our Department. One hundred sixty four episodes of hyperkalemia were treated with insulin plus glucose and were eligible for analysis. Serum potassium levels dropped by 1.18 ± 1.01 mmol/l. Eleven treatments (6.1%) resulted in hypoglycemia and two (1.2%) in severe hypoglycemia. A lower pretreatment blood glucose tended to associate with a higher subsequent risk of hypoglycemia. Age, sex, renal function, an established diagnosis of diabetes or previous treatment were not associated with the development of this complication. We did not register any significant adverse events. Our intravenous regimen combining an infusion of insulin plus glucose effectively reduced serum potassium levels compared to previous studies and associated a low risk of symptomatic hypoglycemia and other complications.

Background:Coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome-Corona Virus 2 has generated significant impact on global health worldwide. COVID-19 can cause pneumonia and organ injury. Chronic kidney disease (CKD) has been associated with increased mortality in previous epidemics, but there is a paucity of data regarding actual risks for non-dialysis CKD patients with COVID-19.Methods:Multicenter, observational cohort study including 136 non-dialysis CKD patients and 136 age- and sex-matched controls that required hospitalization due to COVID-19. Patients with end-stage renal disease, a kidney transplant or without registered baseline glomerular filtration rate prior to COVID-19 infection were excluded. CKD and acute kidney injury (AKI) were defined according to KDIGO criteria.Results:CKD patients had higher white blood cell count and D-dimer and lower lymphocyte percentage. No differences were found regarding symptoms on admission. CKD was associated with higher rate of AKI (61 vs. 24.3%) and mortality (40.4 vs. 24.3%). Patients with AKI had the highest hazard for death (AKI/non-CKD HR:7.04, 95% CI:2.87–17.29; AKI/CKD HR:5.25, 95% CI: 2.29–12.02), followed by CKD subjects without AKI (HR:3.39, 95% CI:1.36–8.46). CKD status did not condition ICU admission or length of in-hospital stay.Conclusions:CKD patients that require hospitalization due to COVID-19 are exposed to higher risk of death and AKI.

Risk stratification and accurate patient prognosis are pending issues in the management of patients with kidney disease. The furosemide stress test (FST) has been proposed as a low-cost, fast, safe, and easy-to-perform test to assess tubular integrity, especially when compared to novel plasma and urinary biomarkers. However, the findings regarding its clinical use published so far provide insufficient evidence to recommend the generalized application of the test in daily clinical routine. Dosage, timing, and clinical outcomes of the FST proposed thus far have been significantly different, which further accentuates the need for standardization in the application of the test in order to facilitate the comparison of results between series. This review will summarize published research regarding the usefulness of the FST in different settings, providing the reader some insights about the possible implications of FST in clinical decision-making in patients with kidney disease and the challenges that research will have to address in the near future before widely applying the FST.

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication in patients undergoing cardiac surgery with extracorporeal circulation (ECC) that increases postoperative complications and mortality. CSA-AKI develops due to a combination of patient- and surgery-related risk factors that enhance renal ischemia–reperfusion injury. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin reduce renal glucose reabsorption, improving tubulo-glomerular feedback, reducing inflammation and decreasing intraglomerular pressure. Preclinical studies have observed that SGLT2i may provide significant protection against renal ischemia–reperfusion injury due to their effects on inadequate mitochondrial function, reactive oxygen species activity or renal peritubular capillary congestion, all hallmarks of CSA-AKI. The VERTIGO (EValuating the Effect of periopeRaTIve empaGliflOzin) trial is a Phase 3, investigator-initiated, randomized, double-blind, placebo-controlled, multicenter study that aims to explore whether empagliflozin can reduce the incidence of adverse renal outcomes in cardiac surgery patients. Methods: The VERTIGO study (EudraCT: 2021-004938-11) will enroll 608 patients that require elective cardiac surgery with ECC. Patients will be randomly assigned in a 1:1 ratio to receive either empagliflozin 10 mg orally daily or placebo. Study treatment will start 5 days before surgery and will continue during the first 7 days postoperatively. All participants will receive standard care according to local practice guidelines. The primary endpoint of the study will be the proportion of patients that develop major adverse kidney events during the first 90 days after surgery, defined as ≥25% renal function decline, renal replacement therapy initiation or death. Secondary, tertiary and safety endpoints will include rates of AKI during index hospitalization, postoperative complications and observed adverse events. Conclusions: The VERTIGO trial will describe the efficacy and safety of empagliflozin in preventing CSA-AKI. Patient recruitment is expected to start in May 2024.