Multifaceted relationship between diabetes and kidney diseases: Beyond diabetes.

Diabetes mellitus is one of the most common causes of chronic kidney disease. Kidney involvement in patients with diabetes has a wide spectrum of clinical presentations ranging from asymptomatic to overt proteinuria and kidney failure. The development of kidney disease in diabetes is associated with structural changes in multiple kidney compartments, such as the vascular system and glomeruli. Glomerular alterations include thickening of the glomerular basement membrane, loss of podocytes, and segmental mesangiolysis, which may lead to microaneurysms and the development of pathognomonic Kimmelstiel-Wilson nodules. Beyond lesions directly related to diabetes, awareness of the possible coexistence of nondiabetic kidney disease in patients with diabetes is increasing. These nondiabetic lesions include focal segmental glomerulosclerosis, IgA nephropathy, and other primary or secondary renal disorders. Differential diagnosis of these conditions is crucial in guiding clinical management and therapeutic approaches. However, the relationship between diabetes and the kidney is bidirectional; thus, new-onset diabetes may also occur as a complication of the treatment in patients with renal diseases. Here, we review the complex and multifaceted correlation between diabetes and kidney diseases and discuss clinical presentation and course, differential diagnosis, and therapeutic oppor-tunities offered by novel drugs.

Biopsy-proven acute tubulointerstitial nephritis in patients treated with immune checkpoint inhibitors: a pooled analysis of case reports.

Introduction: Acute kidney injury (AKI) in cancer patients receiving immune checkpoint inhibitors (ICIs) may recognize multiple causes. Here, we reviewed cases of biopsy-proven acute tubulointerstitial nephritis (ATIN) to describe the clinical characteristics and outcomes of this condition. Method: We conducted a pooled analysis of clinical cases of ICI-related biopsy-proven ATIN up to 1 May 2022. We collected data on clinical characteristics, AKI, biopsy findings, laboratory examinations, and renal outcomes. Results: Eighty-five patients (61.4 ± 19 years, 56 male) were evaluated. Melanoma was the most prevalent diagnosis (51%), followed by non-small cell lung cancer (30%). ICI treatment consisted of PD-1, PDL-1 (nivolumab, pembrolizumab, atezolizumab), and CTLA-4 inhibitors (i) (ipilimumab) or combination PD-1i+CTLA4i. Renal toxicity developed after a median of four cycles of therapy. Fifty-one patients (65.5%) developed the most severe form of AKI- stage 3, including five patients requiring dialysis. All the 19 patients treated with dual ICI blockade developed AKI-stage 3, compared with 29 patients out of the 60 receiving a single agent (p<0.001). Most events were managed with corticosteroids associated with ICI withdrawal. In 15 patients ICI was restarted, but in six (40%) AKI recurred. Overall, 32 patients (40%) presented a complete renal recovery, which chance was inversely associated with dual ICI blockade (OR 0.15, 95CI 0.03-0.7, p=0.01). Conclusion: ICI-related ATIN may develop late after the therapy initiation, presenting as severe AKI, particularly in patients with dual ICI blockade. Although this complication may be partially reversible, concerns remain about the renal function sequelae and the possibility of restarting ICI treatment.

Combined extracorporeal CO2 removal and renal replacement therapy in a pregnant patient with COVID-19: a case report.

Background. Pregnant women are at high risk of Coronavirus disease 2019 (COVID-19) complications, including acute respiratory distress syndrome. Currently, one of the cornerstones in the treatment of this condition is lung-protective ventilation (LPV) with low tidal volumes. However, the occurrence of hypercapnia may limit this ventilatory strategy. So, different extracorporeal CO2 removal (ECCO2R) procedures have been developed. ECCO2R comprises a variety of techniques, including low-flow and high-flow systems, that may be performed with dedicated devices or combined with continuous renal replacement therapy (CRRT). Case description. Here, we report a unique case of a pregnant patient affected by COVID-19 who required extracorporeal support for multiorgan failure. While on LPV, because of the concomitant hypercapnia and acute kidney injury, the patient was treated with an ECCO2R membrane inserted in series after a hemofilter in a CRRT platform. This combined treatment reducing hypercapnia allowed LPV maintenance at the same time while providing kidney replacement and ensuring maternal and fetal hemodynamic stability. Adverse effects consisted of minor bleeding episodes due to the anticoagulation required to maintain the extracorporeal circuit patency. The patient's pulmonary and kidney function progressively recovered, permitting the withdrawal of any extracorporeal treatment. At the 25th gestational week, the patient underwent spontaneous premature vaginal delivery because of placental abruption. She gave birth to an 800-gram female baby, who three days later died because of multiorgan failure related to extreme prematurity. Conclusions. This case supports using ECCO2R-CRRT combined treatment as a suitable approach in the management of complex conditions, such as pregnancy, even in the case of severe COVID-19.

Extracorporeal Carbon Dioxide Removal: From Pathophysiology to Clinical Applications; Focus on Combined Continuous Renal Replacement Therapy.

Lung-protective ventilation (LPV) with low tidal volumes can significantly increase the survival of patients with acute respiratory distress syndrome (ARDS) by limiting ventilator-induced lung injuries. However, one of the main concerns regarding the use of LPV is the risk of developing hypercapnia and respiratory acidosis, which may limit the clinical application of this strategy. This is the reason why different extracorporeal CO2 removal (ECCO2R) techniques and devices have been developed. They include low-flow or high-flow systems that may be performed with dedicated platforms or, alternatively, combined with continuous renal replacement therapy (CRRT). ECCO2R has demonstrated effectiveness in controlling PaCO2 levels, thus allowing LPV in patients with ARDS from different causes, including those affected by Coronavirus disease 2019 (COVID-19). Similarly, the suitability and safety of combined ECCO2R and CRRT (ECCO2R-CRRT), which provides CO2 removal and kidney support simultaneously, have been reported in both retrospective and prospective studies. However, due to the complexity of ARDS patients and the limitations of current evidence, the actual impact of ECCO2R on patient outcome still remains to be defined. In this review, we discuss the main principles of ECCO2R and its clinical application in ARDS patients, in particular looking at clinical experiences of combined ECCO2R-CRRT treatments.

Successful Extracorporeal Blood Purification Therapy using Double Haemoadsorption Device in Severe Endotoxin Septic Shock: A Case Report.

Introduction: In patients admitted to the Intensive Care Unit (ICU), sepsis can lead to acute kidney injury (AKI), which may require the initiation of continuous renal replacement therapy (CRRT) in 15-20% of cases. There is no consensus about the best extracorporeal treatment to choose in septic patients with AKI. Case presentation: We describe the case of a 70-year-old woman admitted to the ICU with a severe endotoxin septic shock due to Neisseria meningitidis serogroup C. Despite prompt medical intervention, including fluid resuscitation, high dose vasopressor, inotrope support, and broad-spectrum antimicrobial treatment, in a few hours patient's haemodynamic worsened and she developed multi-organ failure, including severe AKI, requiring CRRT. So, continuous veno-venous haemodiafiltration was started, using an oXiris® haemodiafilter set, in series with an adsorber device (CytoSorb®). After 48 hours of this combined extracorporeal treatment, haemodynamic parameters improved, allowing a significant reduction of the vasoactive therapy, with a concomitant decrease in endotoxin and inflammatory markers serum levels. In the following days patient's conditions still improved and renal function recovered. Conclusions: Timely extracorporeal blood purification therapy, using a double haemoadsorption device, may be effective in the management of severe septic shock.

The Evolving Scenario of COVID-19 in Hemodialysis Patients.

Coronavirus disease 2019 (COVID-19) is a rapidly changing disease. Therefore, in this study, to evaluate the evolution of COVID-19 in hemodialysis patients, we retrospectively compared patients affected by COVID-19 during the first pandemic waves of 2020 (from March to December 2020-Group 1) with patients with COVID-19 from September 2021 to February 2022 (Group 2) after the full completion of vaccination. Group 1 was constituted of 44 patients (69.3 ± 14.6 years), and Group 2 of 55 patients (67.4 ± 15.3 years). Among Group 2, 52 patients (95%) were vaccinated. Patients of Group 2, compared with Group 1, were more often asymptomatic (38 vs. 10%, p = 0.002) and reported less frequent fever and pulmonary involvement. At diagnosis, Group 2 showed a significantly higher number of lymphocytes and lower levels of circulating IL-6 (16 ± 13.3 vs. 41 ± 39.4 pg/mL, p = 0.002). Moreover, in Group 2, inflammatory parameters significantly improved after a few days from diagnosis. Patients of Group 2 presented a lower hospitalization rate (12.7 vs. 38%, p = 0.004), illness duration (18.8 ± 7.7 vs. 29.2 ± 19.5 days, p = 0.005), and mortality rate (5.4 vs. 25%, p = 0.008). Finally, responders to the vaccination (80% of vaccinated patients) compared with nonresponders showed a reduction in infection duration and hospitalization (5 vs. 40%, p = 0.018). In conclusion, we found that COVID-19 presentation and course in hemodialysis patients have improved over time after the implementation of vaccine campaigns. However, due to the evolving nature of the disease, active surveillance is necessary.

Uric acid lowering for slowing CKD progression after the CKD-FIX trial: a solved question or still a dilemma?

Hyperuricemia has been associated with several cardiovascular risk factors and is a well-known predictor of kidney disease. In vitro studies as well as animal models highlighted a role for uric acid in the development and progression of haemodynamic and tissue damage at the renal level leading to glomerular and tubulointerstitial abnormalities. Urate-lowering treatment, especially by xanthine oxidase inhibitors, has been proposed in order to improve kidney outcomes. However, recent randomized controlled trials failed to demonstrate a beneficial effect of allopurinol or febuxostat on renal disease, casting doubts on the role of this therapeutical approach to improve nephroprotection. We provide a critical overview of current literature on this topic and offer a possible interpretation of results from recent intervention trials with urate-lowering treatment on renal outcomes.

Changes of Acute Kidney Injury Epidemiology during the COVID-19 Pandemic: A Retrospective Cohort Study.

To evaluate the impact of the Coronavirus Disease-19 (COVID-19) pandemic on the epidemiology of acute kidney injury (AKI) in hospitalized patients, we performed a retrospective cohort study comparing data of patients hospitalized from January 2016 to December 2019 (pre-COVID-19 period) and from January to December 2020 (COVID-19 period, including both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-negative and positive patients). AKI was classified by evaluating the kinetics of creatinine levels. A total of 51,681 patients during the pre-COVID-19 period and 10,062 during the COVID-19 period (9026 SARS-CoV-2-negative and 1036 SARS-CoV-2-positive) were analyzed. Patients admitted in the COVID-19 period were significantly older, with a higher prevalence of males. In-hospital AKI incidence was 31.7% during the COVID-19 period (30.5% in SARS-CoV-2-negative patients and 42.2% in SARS-CoV-2-positive ones) as compared to 25.9% during the pre-COVID-19 period (p < 0.0001). In the multivariate analysis, AKI development was independently associated with both SARS-CoV-2 infection and admission period. Moreover, evaluating the pre-admission estimated glomerular filtration rate (eGFR) we found that during the COVID-19 period, there was an increase in AKI stage 2−3 incidence both in patients with pre-admission eGFR < 60 mL/min/1.73 m2 and in those with eGFR ≥ 60 mL/min/1.73 m2 ("de novo" AKI). Similarly, clinical outcomes evaluated as intensive care unit admission, length of hospital stay, and mortality were significantly worse in patients admitted in the COVID-19 period. Additionally, in this case, the mortality was independently correlated with the admission during the COVID-19 period and SARS-CoV-2 infection. In conclusion, we found that during the COVID-19 pandemic, in-hospital AKI epidemiology has changed, not only for patients affected by COVID-19. These modifications underline the necessity to rethink AKI management during health emergencies.

Impact of eGFR rate on 1-year all-cause mortality in patients with stable coronary artery disease.

BACKGROUND: Coronary artery disease (CAD) is a leading cause of mortality and is often complicated by chronic kidney disease. We sought to investigate the prevalence of different degree of estimated glomerular filtration rate (eGFR) reduction, the clinical and bio-humoral correlates, its relationship with therapeutic management, and its predictive role on 1-year all-cause mortality, in patients with stable CAD. METHODS: We studied 4,130 patients with stable CAD recruited in a prospective, observational, nationwide study (START, STable coronary Artery diseases RegisTry) in Italy. Baseline clinical characteristics, pharmacological treatment, and all-cause 1-year mortality were evaluated according to groups of eGFR (<30; 30-59; 60-89; ≥90 ml/min/1.73 m2) at baseline. RESULTS: The presence and the degree of chronic kidney disease entailed an unfavorable risk profile, since it was gradually associated with more comorbidities. Furthermore, progressively lower eGFR values were associated to lower diastolic blood pressure and hemoglobin values. As eGFR lowers, optimal medical treatment and its persistence overtime is reduced. Multivariate analysis showed that progressively lower eGFR significantly correlated with all-cause 1-year mortality [hazard ratio (HR): 1.02; 95% confidence intervals (CI): 1.01-1-03; p = 0.0001]. CONCLUSIONS: Low eGFR is associated with an increasing risk of all-cause mortality in patients with stable CAD. Chronic kidney disease may hamper the optimization of treatment limiting the use of drugs which may favorably impact cardiovascular and renal outcomes.

Treating Hyperuricemia: The Last Word Hasn't Been Said Yet.

Gout as well as asymptomatic hyperuricemia have been associated with several traditional cardiovascular risk factors and chronic kidney disease. Both in vitro studies and animal models support a role for uric acid mediating both hemodynamic and tissue toxicity leading to glomerular and tubule-interstitial damage, respectively. Nevertheless, two recent well designed and carried out trials failed to show the benefit of allopurinol treatment on kidney outcomes, casting doubts on expectations of renal protection by the use of urate lowering treatment. With the aim of providing possible explanations for the lack of effect of urate lowering treatment on chronic kidney disease progression, we will critically review results from all available randomized controlled trials comparing a urate-lowering agent with placebo or no study medication for at least 12 months and report renal clinical outcomes.

Two-Day ABPM-Derived Indices and Mortality in Hemodialysis Patients.

BACKGROUND: Blood pressure (BP) and arterial stiffness are known cardiovascular risk factors in hemodialysis (HD) patients. This study examines the prognostic significance of 44-hour BP circadian rhythm and ambulatory arterial stiffness index (AASI) in this population. METHODS: A total of 80 HD patients underwent 44-hour ambulatory BP monitoring (ABPM) with a TM-2430 monitor during a standard midweek interdialytic interval and followed up for 4.5 ± 1.7 years. The end point was all-cause mortality. RESULTS: About 76% of participants were hypertensive (40% uncontrolled), 62% were nondippers, and 23% risers during the first interdialytic day, whereas 73% and 44% in the second day, respectively. During follow-up, 31 patients (40%) died. These showed higher pulse pressure (PP) and AASI44 and AASI of the second interdialytic period. The incidence of all-cause mortality was higher in HD patients with AASI44 > median, i.e. >0.54 (interquartile range = 14) (54% vs. 28%, χ 2 = 5.3, P = 0.021) when compared with those with lower AASI44. Second, but not first-day ABPM-derived parameters, namely nondipping (log-rank χ 2 = 6.10, P = 0.0134) or reverse dipping status (log-rank χ 2 = 5.32, P = 0.210) and arterial stiffness index (log-rank χ 2 = 6.61, P = 0.0101) were significantly related to greater mortality. CONCLUSIONS: These findings indicate a strong relationship between arterial stiffness and cardiovascular risk and support a wider use of 44-hour ABPM recording for risk stratification in HD patients.

Uric acid and angiotensin II additively promote inflammation and oxidative stress in human proximal tubule cells by activation of toll-like receptor 4.

Renal proximal tubular cells (PTECs) participate in several mechanisms of innate immunity, express toll-like receptors (TLRs), and proinflammatory cytokines. Hyperuricemia may be a promoter of inflammation and renal damage. Angiotensin II (Ang II) modulate immune and inflammatory responses in renal tubular cells. With the aim to evaluate the effect of uric acid (UA) and Ang II on oxidative stress and inflammation mediated by toll-like receptor 4 (TLR4) activation in human PTECs, human kidney 2 (HK2) were incubated for 24 hr with UA (12 mg/dl) and Ang II (10 -7 M). HK2 were pretreated with an antagonist of TLR4 (TAK 242), valsartan or losartan. The genic expression of TLR4, monocyte chemoattractant protein-1 (MCP1), and Nox4 was quantified with reverse transcription polymerase chain reaction, proteins were evaluated with Western blot. The incubation of HK2 either with UA or with Ang II determines an increased expression of TLR4, production of proinflammatory cytokines as MCP1 and pro-oxidants as Nox4 ( p < 0.05). TAK 242 attenuates the expression of MCP1 induced both by UA and Ang II. Valsartan attenuated all the effects we described after exposure to Ang II but not those observed after UA exposure. At variance, pretreatment with losartan, which inhibits UA internalization, attenuates the expression of TLR4, MCP1, and Nox4 in cells previously treated with UA, Ang II, and UA plus Ang II. Proinflammatory pathways are induced in an additive manner by UA and Ang II ( p < 0.05) and might be mediated by TLR4 in PTECs. Renin-angiotensin-aldosterone system (RAAS) activation, hyperuricemia, and innate immunity interplay in the development of chronic tubular damage and the interaction of several nephrotoxic mechanisms blunt the protective effect of RAAS inhibition.

Hypertensive Versus HIV-infected Patients: Who Has the Greatest Target Organ Damage? Comparison of Carotid Plaque Prevalence, Intima Media Thickness and Renal Resistive Index in the Two Groups of Patients.

OBJECTIVES: to compare the prevalence of target-organ damage (TOD), defined as carotid plaque, or intima media thickness, cIMT, >0.9 mm, and that of increased renal resistive index (RRI), among HIV-1-infected patients and uninfected hypertensive patients (HT-non HIV). METHODS: HIV-infected patients aged ≥ 18 years and virologically suppressed were matched with pair-age, sex and BMI HT-non HIV. Patients on antihypertensive treatment were excluded. All patients' cIMT and RRI were evaluated with ultrasonography. Data were analysed throughout Χ2 test, analysis of variance and logistic regression. RESULTS: Fifty-nine HIV-infected patients were enrolled (71% men) and matched with 59 HT-non HIV. No differences were found in cIMT values (p=0.827) and in the prevalence of TOD between HIV-infected patients and HT-non HIV (36% vs 38%, p= 0.79). Among HIV-infected patients, those hypertensive had significantly higher prevalence of TOD (46% vs 21%, P< 0.05) and higher cIMT (0.747 ± 0.104 vs 0.654 ±0.100 mm, p = 0.0185). Patients with TOD were older (p= 0.004) and more frequently current smokers (p= 0.022). At the logistic regression analysis, TOD was significantly related to age (p=0.04, 95%CI 1.0-1.1) and smoke, current (p=0.178, 95%CI1.2-12.8) or previous (p=0.04, 95%CI 1.0-7.2). Mean RRI were identical for both HIV-1 infected and uninfected patients (0.60, SD± 0.05 and 0.60, SD± 0.04, respectively, p=0.996). CONCLUSIONS: In our study TOD was associated to hypertension, older age and smoke, but not to HIV serostatus itself, confirming the major importance of traditional risk factors and the need of risk assessment and cardiovascular prevention measures in HIV-infected patients.

[The uric acid cardio-nephropathy].

Uric acid is a product of purine catabolism formed by the activity of xanthine-oxidase and prevalently excreted by the kidney. In vivo, urate is known to have both an anti- or pro-oxidant role depending on several biological conditions. New evidence suggests that chronic hyperuricemia can contribute to hypertension development, kidney disease and cardiovascular risk. The pathophysiologic mechanisms are various, such as endothelial dysfunction and oxidative stress, vasoconstriction and stimulation of renin angiotensin system. These processes act at the kidney level, within arterioles and tubular cells, as well as at the systemic vasculature and tissue level causing hypertension, atherosclerosis and myocardial dysfunction. In recent years evidence has grown that asymptomatic hyperuricemia is a possible risk factor for the development of hypertension, diabetes as well as renal and cardiovascular events. Preliminary clinical evidence suggests that lowering uric acid levels by the use of xanthine-oxidase inhibitors may improve cardiovascular and renal risk. Several ongoing trials, both with allopurinol and febuxostat, will clarify this issue in the upcoming years.

Peripheral artery disease and blood pressure profile abnormalities in hemodialysis patients.

BACKGROUND: Patients undergoing chronic hemodialysis (HD) are at increased risk for peripheral artery disease (PAD). Both ankle-brachial index (ABI) and ambulatory blood pressure monitoring (ABPM) in the interdialytic period have been shown to be strong predictors of all-cause mortality. METHODS: This cross-sectional study investigated the relationship between ABPM profile and ABI in 81 HD patients. ABPM was measured throughout a 44-h midweek interdialytic period. Pre-dialysis ABI was evaluated with a BOSO ABI device. An ABI value <0.9 or ≥1.3 was defined as abnormal. RESULTS: In the whole study group (72 % males, mean age 67 ± 14 years), there was an increase in BP (p < 0.05) and in systolic BP night/day ratio (n/dSR, p = 0.01) during the interdialytic period. Patients with abnormal ABI (n = 29) more frequently had a positive history for cerebrovascular accident and PAD and higher proBNP values than those with normal ABI (n = 52). No difference was detected among ABPM-derived components except for the n/dSR (p = 0.02). Patients with abnormal ABI showed a significantly increased n/dSR (p = 0.02) and ambulatory arterial stiffness index (AASI) (p = 0.006) on the second day compared to the first. Patients with n/dSR >1 during day 2 (n = 34) were older, showed significantly higher proBNP and AASI and were more likely to reveal abnormal ABI compared to those with a lower n/dSR (p = 0.006). CONCLUSIONS: Abnormal ABI in HD patients is associated to changes in interdialytic ABPM pattern, namely higher n/dSR on day 2. These data may indicate the pathophysiological mechanisms underlying the worse outcome observed in HD patients.

Microalbuminuria in primary hypertension: a guide to optimal patient management?

Accurate assessment of the global risk profile is considered a prerequisite for the optimal management of hypertensive patients. In particular, the evaluation of subclinical organ damage, namely left ventricular hypertrophy, peripheral atherosclerosis and renal function, plays a key role in optimizing therapeutic targets and strategy in individual patients. Urine albumin excretion is a low-cost, easy-to-use test and a powerful predictor of cardiovascular diseases. The search for albuminuria has, therefore, become routine in the evaluation of hypertensive patients. Moreover, albuminuria has been shown to be associated with early signs of extra-renal organ damage such as left ventricular hypertrophy, and carotid atherosclerosis. Under effective antihypertensive treatment, changes in subclinical organ damage over time, especially regression of left ventricular hypertrophy, are paralleled by modification of risk status and may serve as intermediate endpoints for treatment. More recently, changes in albuminuria have also been proposed to reflect changes in the risk of cardiovascular events. If this is confirmed by large well-designed studies, microalbuminuria may not simply be regarded as a risk predictor but become itself an independent target for treatment.

Renin-angiotensin-aldosterone system blockade in chronic kidney disease: current strategies and a look ahead.

The Renin-Angiotensin-Aldosterone System (RAAS) is profoundly involved in the pathogenesis of renal and cardiovascular organ damage, and has been the preferred therapeutic target for renal protection for over 30 years. Monotherapy with either an Angiotensin Converting Enzime Inhibitor (ACE-I) or an Angiotensin Receptor Blocker (ARB), together with optimal blood pressure control, remains the mainstay treatment for retarding the progression toward end-stage renal disease. Combining ACE-Is and ARBs, or either one with an Aldosterone Receptor Antagonist (ARA), has been shown to provide greater albuminuria reduction, and to possibly improve renal outcome, but at an increased risk of potentially severe side effects. Moreover, combination therapy has failed to provide additional cardiovascular protection, and large prospective trials on hard renal endpoints are lacking. Therefore this treatment should, at present, be limited to selected patients with residual proteinuria and high renal risk. Future studies with novel agents, which directly act on the RAAS at multiple levels or have a more favourable side effect profile, are greatly needed to further explore and define the potential for and the limitations of profound pharmacologic RAAS inhibition.