Urinary Post-Translationally Modified Fetuin-A (uPTM-FetA) in Chronic Kidney Disease Patients with and without Diabetic Kidney Disease.

Background and Objectives: A novel post-translational modification (PTM) fragment derived from the cleavage of Fetuin-A (PTM-FetA) has recently emerged as a sensitive biomarker for kidney damage in diabetic patients, but evidence in other chronic renal diseases is lacking. In this pilot study, we aimed at evaluating the clinical significance of urinary PTM-FetA (uPTM-FetA) in a mixed cohort of patients with non-advanced chronic kidney disease (CKD) secondary to diabetic kidney disease (DKD) or other causes. Materials and Methods: We enrolled 47 adult patients with CKD (mean CKD-Epi 40.10 ± 16.5 mL/min/1.73 m2) due to DKD (n = 34) or other etiology (n = 13). uPTM-FetA was measured in the urine using a commercially available ELISA kit. Fifteen healthy individuals served as controls. Results: Collectively, all CKD patients displayed remarkably higher levels of uPTM-FetA than controls (0.84 [0.10-1.15] vs. 29.68 [2.50-55.16] ng/mL p = 0.0005), but values were lower in non-DKD than in DKD patients (1.66 [0.09-4.19] vs. 13.9 [0.01-45.02] ng/mL; p = 0.01). uPTM-FetA showed a great diagnostic capacity at ROC analyses to identify the presence of CKD (AUC 0.776; p < 0.001) and, within CKD patients, to discriminate the diabetic and non-diabetic etiology (AUC 0.673; p = 0.02). At multivariate correlation analyses, proteinuria (ß = 0.442; p = 0.02) and BMI (ß = -0.334; p = 0.04) were the sole independent predictors of uPTM-FetA in this study population. Conclusions: uPTM-FetA could be a novel sensitive biomarker at the crossroad of chronic renal damage and metabolic dysfunction. Additionally, this biomarker could also represent a non-invasive, complementary tool for discriminating among different CKD etiologies (DKD vs. non-DKD) in difficult cases or when renal biopsy is not available.

Self-Reported Physical Inactivity and Mood Disturbances in End-Stage Kidney Disease (ESKD) Patients on Chronic Dialysis Treatment.

BACKGROUND: Physical inactivity and mood disturbances are key issues in individuals with end-stage kidney disease (ESKD) and may lead to poor clinical outcomes. METHODS: We performed a pilot, observational study to explore the possible relationships between the self-reported level of physical activity (IPAQ) and the severity of mood disturbances (BDI score) in a cohort of 58 ESKD patients undergoing chronic hemodialysis (HD; n = 30) or peritoneal dialysis (PD; n = 28). RESULTS: Overall, ESKD patients were severely inactive (median METs: 590 [460-1850]) and the intensity of overall and walking physical activity was mostly low to moderate. HD individuals appeared less active than PD (METs 550 [250-1600] vs. 1080 [750-1730]; p = 0.003) and were also less prone to walking (METs 180 ± 90 vs. 320 ± 100; p = 0.01), while a barely statistical difference was noticed for the time spent sitting. ESKD individuals displayed a median BDI score of 17 [12-21], which indicated, on average, the presence of borderline depression, which was apparently more evident among HD individuals. A strong, inverse correlation was found between self-reported METs and BDI scores (R = -0.78; p < 0.0001), while such scores paralleled the time spent sitting during a weekday (R = 0.45; p = 0.0004) and a weekend day (R = 0.40; p = 0.002). CONCLUSIONS: In ESKD patients on chronic dialysis, physical inactivity and mood disturbances might be significantly inter-connected, thereby amplifying their relative impact on quality of life, dysautonomia and long-term outcomes. Future studies on larger populations are recommended to confirm these preliminary observations. Promoting strategies to improve fitness, along with greater attention to physiological aspects, should be incorporated into the clinical management of ESKD patients.

Urinary Marinobufagenin in Patients with Non-Advanced Chronic Kidney Disease: A Cross-Sectional Study.

Background and Objectives: The global prevalence of chronic kidney disease (CKD) is on the rise, posing important challenges for healthcare systems. Thus, the search for new factors potentially involved in the pathogenesis, progression and complications of early CKD remains urgent. Marinobufagenin (MBG) is a natriuretic endogenous cardiotonic steroid, and increased circulating levels of it may accelerate kidney damage. In this study, we explored the possible clinical significance of measuring urinary marinobufagenin (uMBG) in patients with non-advanced CKD. Materials and Methods: One hundred and eight adult CKD patients (mean age 71.6 ± 10 years, 70.4% male; mean eGFR 40.54 ± 17 mL/min/1.73 m2) were enrolled in this cross-sectional study. uMBG was measured together with a series of clinical, anthropometric, laboratory and instrumental analyses. Twenty-five healthy matched subjects served as controls for the uMBG measurement. Results: The uMBG values were lower in the patients with CKD as compared to those of the controls (0.37 [IQR: 0.25-0.45] vs. 0.64 [0.46-0.78] nmol/L. p = 0.004), and a significant trend in eGFR levels was noticed across the decreasing uMBG tertiles (p = 0.03). Regarding the correlation analyses, the uMBG values remained robustly associated with the eGFR in multivariate models employing either uMBG or eGFR as the dependent variable (ß = 0.248; p = 0.01 and ß = 0.139; p = 0.04, respectively). Besides the eGFR, the independent predictors of uMBG values in this population were the use of statins (ß = -0.326; p = 0.001), the presence of diabetes (ß = 0.243; p = 0.009) and urine sodium (ß = 0.204; p = 0.01). Conclusions: Reduced uMBG excretion may reflect impaired renal clearance, which may contribute to the detrimental effects attributed to this hormone due to systemic accumulation. Future studies are needed to clarify the biological mechanisms placing uMBG at the crossroad of sodium intake and the presence of diabetes in CKD-suffering individuals and to verify whether a statin treatment may somewhat limit the detrimental effects of MBG in the presence of impaired renal function.

Marinobufagenin, left ventricular geometry and cardiac dysfunction in end-stage kidney disease patients.

PURPOSE: Left ventricular hypertrophy (LVH) is remarkably prevalent among end-stage kidney disease (ESKD) on chronic dialysis and has a strong prognostic value for adverse outcomes. In experimental models, the endogenous cardiotonic steroid Marinobufagenin (MBG) promotes cardiac hypertrophy and accelerates uremic cardiomyopathy. In this study, we investigated the possible relationships between MBG, LV geometry and cardiac dysfunction in a clinical setting of ESKD. METHODS: Plasmatic MBG was measured in 46 prevalent ESKD patients (n = 30 HD, n = 16 PD) together with a thorough laboratory, clinical, bioimpedance and echocardiography assessment. Different patterns of LV geometry were defined by left ventricular mass index (LVMi) and ventricular morphology. Diastolic dysfunction was diagnosed by the ASE/EACVI criteria. RESULTS: MBG levels were significantly higher in ESKD patients than in healthy controls (p = 0.001) and more elevated in PD than in HD (p = 0.02). At multivariate analyses, E/e' (ß = 0.38; p = 0.009) and LVMi (ß = 0.42; p = 0.02) remained the sole independent predictors of MBG. A statistically significant trend in MBG levels (p = 0.01) was noticed across different patterns of LV geometry, with the highest values found in eccentric LVH. MBG levels were higher in the presence of diastolic dysfunction (p = 0.01) and this substance displayed a remarkable diagnostic capacity in distinguish patients with normal LV geometry, LV hypertrophy and, particularly, eccentric LVH (AUC 0.888; p < 0.0001) and diastolic dysfunction (AUC 0.79; p = 0.001). CONCLUSIONS: Deranged plasma MBG levels in ESKD patients on chronic dialysis reflect alterations in LV structure and function. MBG may, thus, candidate as a novel biomarker for improving cardiac assessment in this high-risk population.

[Malnutrition and dialytic adequacy in patients on peritoneal dialysis: two sides of the same coin?]

Dialysis adequacy and a state of "eunutrition" are two essential elements to consider in the evaluation of patient undergoing dialysis treatment. Dialysis inadequacy is often associated with malnutrition, and the combination of these two factors significantly worsens the prognosis. In the following monocentric and prospective study, the correlation between nutritional markers and dialytic adequacy was tested in a cohort of patients permanently followed by the peritoneal dialysis clinic, followed consistently for two years. It was therefore evaluated if modification of dialysis therapy, aimed to reach adequacy parameters, could simultaneously improve metabolic parameters. Although there were no frankly malnourished patients, the group of "inadequate" patients had a significantly lower nPCR value. In this same group, after about 6 months, therapeutic measures adopted allowed an overall improvement in Kt/V and nPCR, with other nutritional parameters (such as body weight, albumin, pre-albumin, total cholesterolemia) remaining stable. At the end of the follow-up period the Kt/V of the "inadequate" (<1.7) was higher ​​than the baseline, reaching statistical significance at the 12th and 24th months. Early identification of a dialysis inadequacy, therefore, allowed the execution of therapeutic changes necessary to achieve a lasting improvement in "adequate" replacement therapy, and a temporary improvement in the patient's nutritional status. Suddenly, despite the persistent improvement of the Kt/V there was a new reduction of the nPCR.

Nephrosclerosis impacts time trajectory of renal function and outcomes in elderly individuals with chronic kidney disease.

Despite hypertension ranks among the leading causes of chronic kidney disease (CKD), the impact of chronic hypertensive nephropathy, the so-called 'nephrosclerosis' (NS), on CKD progression is often unpredictable, particularly in elderly population. We have conducted a prospective, observational study to define renal function patterns and outcomes in elderly CKD individuals with or without NS. Three hundred four individuals with an already established CKD were categorized according to the etiology of CKD. NS was defined as the presence of CKD associated with long-term essential hypertension, hypertensive retinopathy, left ventricular hypertrophy and minimal proteinuria. Time trajectories in estimated glomerular filtration rate (eGFR) (CKD-Epi) were computed over a 4-year follow-up. In addition, we analyzed the occurrence of a composite outcome of doubling of serum creatinine levels, eGFR reduction ≥25% and/or the need of chronic renal replacement therapy. CKD was secondary to nephrosclerosis (CKD-NS) in 220 (72.3%). In the whole cohort, the average estimated annual GFR slope was 1.8 mL/min/1.73 m2 eGFR decline was slower in CKD-NS as compared with others (1.4 vs 3.4 mL/min/1.73 m2; p<0.001). The composite renal outcome during follow-up occurred less frequently among elderly with CKD-NS (16/204 vs 14/70; p=0.01, crude HR 0.43, 95% CI 0.22 to 0.85) and was associated at logistic analyses with the etiology of CKD, background cardiovascular disease, total and low density lipoproteins (LDL) cholesterol, and glycemia levels (p value was ranging from 0.01 to 0.05). Despite being highly prevalent in the elderly, NS is associated with a more favorable renal disease course as compared with other conditions.

An open-label, randomized, placebo-controlled study on the effectiveness of a novel probiotics administration protocol (ProbiotiCKD) in patients with mild renal insufficiency (stage 3a of CKD).

PURPOSE: Gut dysbiosis has been described in advanced, but not in initial stages of CKD. Considering the relevant impact of gut dysbiosis on renal and cardiovascular risk, its diagnosis and treatment are clinically relevant. METHODS: We designed, open-label, placebo-controlled intervention study (ProbiotiCKD) to evaluate gut microbiota metabolism in a cohort of KDIGO CKD patients (n = 28) at baseline and after a randomly assigned treatment with probiotics or placebo. Gut microbiota status was evaluated on:. RESULTS: Basal mean fecal Lactobacillales and Bifidobacteria concentrations were abnormally low in both groups, while urinary indican and 3-MI levels were, indicating a mixed (fermentative and putrefactive) dysbiosis. After treatment, mean fecal Lactobacillales and Bifidobacteria concentrations were increased, only in the probiotics group (p < 0.001). Conversely, mean urinary indican and 3-MI levels only in the group treated with probiotics (p < 0.001). Compared to placebo group, significant improvements of C-reactive protein (p < 0.001), iron (p < 0.001), ferritin (p < 0.001), transferrin saturation (p < 0.001), ß2-microglobulin (p < 0.001), serum iPTH and serum calcium were observed only in the probiotics group. CONCLUSIONS: ProbiotiCKD is the first intervention study demonstrating that an intestinal mixed dysbiosis is present even in early CKD stage and can be effectively corrected by the novel mode of administration of high-quality probiotics with improvement of inflammatory indices, iron status and iPTH stabilization.

Correction to: An open-label, randomized, placebo-controlled study on the effectiveness of a novel probiotics administration protocol (ProbiotiCKD) in patients with mild renal insufficiency (stage 3a of CKD).

In the original publication of the article, few of the authors were missed in the author group.

Effect of post-nephrectomy acute kidney injury on renal outcome: a retrospective long-term study.

PURPOSE: The effects on renal prognosis of acute kidney injury after elective unilateral nephrectomy are ill-defined. We evaluated as whether post-operative acute kidney injury modifies renal outcome over the long term. METHODS: This is a retrospective study examining all consecutive adult patients referred to three Nephrology Units and that had previously undergone elective unilateral nephrectomy. We evaluated the association of post-nephrectomy acute kidney injury with the combined renal outcome of chronic dialysis requirement, ≥ 40% decline in glomerular filtration rate or new-onset severe proteinuria (> 500 mg/24 h). Clinical correlates of acute kidney injury and renal outcome were also examined. RESULTS: 106 patients were enrolled. 52 patients had post-operative acute kidney injury with a median increment of serum creatinine of 0.67 [0.48-0.86] mg/dl; in these patients, serum creatinine and urea increased from the first day post-nephrectomy while contraction of urinary output was found in 7 patients. Older age [OR: 1.72; 95% CI 1.05-2.82; P = 0.030] associated with post-operative acute kidney injury. Over a median follow-up of 8.9 [95% CI 3.1-24.2] years, the combined renal outcome occurred, respectively, in 28 (53.8%) and 14 (25.9%) patients with and without acute kidney injury (P = 0.003). Logistic regression analysis showed that acute kidney injury (OR: 3.22; 95% CI 1.35-7.66; P = 0.008) and male gender (OR: 2.72; 95% CI 1.08-6.85; P = 0.034) were associated with poor renal outcome after adjustment for main comorbidities. CONCLUSIONS: In our population of referred patients, acute kidney injury after unilateral nephrectomy was common and associated with progressive chronic kidney disease, especially in older males.

How to improve duration and efficiency of the antiproteinuric response to Ramipril: RamiPROT-a prospective cohort study.

BACKGROUND: The antiproteinuric pharmacokinetics of Ramipril in response to different doses and modalities of administration has been poorly investigated so far. STUDY DESIGN: Prospective, open-label and not placebo controlled study. SETTING AND PARTICIPANTS: 40 Caucasian adult patients having GFR ≥ 50 mL/min, proteinuria 1-3 g/day; SBP/DBP ≤ 150/90 mmHg were recruited between June 2014 and November 2014. FACTOR AND OUTCOME: Impact on 24 h proteinuria and fractioned proteinuria of Ramipril given at different dosages (2.5 mg/day or Ramipril 5 mg/day or Ramipril 10 mg/day) and with different daily administration modalities (single or two divided doses) for cycles of 10 days. MEASUREMENTS: At the end of each cycle, 24 h and fractioned proteinuria on three timed urinary collections (morning, afternoon and night) were measured. RESULTS: Compared to baseline, Ramipril significantly reduced 24 h proteinuria at each dose and modality of administration. In particular, the greatest effects were evident with the higher and divided dose of the drug. The analysis of the fractioned proteinuria showed that the greatest reduction was obtained in the night urinary collection by administering Ramipril 10 mg/day in two divided doses. LIMITATIONS: Small sample size. CONCLUSIONS: Ramipril reduces proteinuria at any of the tested doses. Although the using of high and divided doses seems to maximize the antiproteinuric effect of the drug, possibly due to a better pharmacological coverage of the nocturnal period.

[Is it feasible to improve the duration and the efficiency of Ramipril anti-proteinuric response?]. / È possibile migliorare la durata e l'efficacia della risposta anti-proteinurica di Ramipril?

BACKGROUND: Ramipril administered once daily is characterized by an attenuation of its pharmacological activity in the following 24 hours, whose effects on antiproteinuric activity have not yet been investigated. METHODS: The antiproteinuric efficacy of Ramipril has been evaluated in a cross-over study in 20 patients with renal disease, proteinuria and hypertension (GFR50 mL / min, proteinuria <3 g / day; SBP/DBP 150/90 mmHg). Proteinuria was measured over 24 hours on three consecutive urine collections (morning, afternoon and night) in the absence of antiproteinuric drugs and after ten days of treatment with single morning administration of Ramipril 2.5 mg or Ramipril 10 mg. RESULTS: At baseline: mean proteinuria was not significantlychanged over the course of the three urinary collections (88 7.2 mg/h in the morning of 80 10.5 mg/h in the afternoon and 81 10.1 mg/hr during the night). After Ramipril 2.5 mg/day: slight reduction in mean proteinuria, with no significant differences between collections (80 11 mg/h in the morning, 69 7.4 mg/h in the afternoon and 75 9.1 mg/h during the night). After Ramipril 10 mg/day: afternoon and night values of proteinuria were significantly reduced compared to baseline; noctural proteinuria was significantly lower than morning value (51 7.5 mg/h vs. 81 10 mg/h, p <0.05). CONCLUSION: The antiproteinuric effectiveness of Ramipril tends to decrease significantly over the 24hours after a single daily administration. An increase and/or division of Ramipril dose might help to stabilize and to maximizeits antiproteinuric effectiveness.

Can renal sonography be a reliable diagnostic tool in the assessment of chronic kidney disease?

OBJECTIVES: Kidney size has been found to be correlated with anthropometric features and kidney function. Therefore, we postulate that if the conventionally measured renal sonographic parameters (pole-to-pole length, width, and parenchymal thickness) are taken according to standardized rules and corrected for body height, their association with kidney function could be strengthened, thus helping validate renal sonographic information for a better assessment of chronic kidney disease (CKD) status. METHODS: This cross-sectional study included 72 stable adult patients with stage 1 to 4 CKD. Sonographic parameters were obtained from both kidneys and averaged, and the measurements obtained were further corrected for patients' body height. The glomerular filtration rate (GFR) was estimated by the Chronic Kidney Disease Epidemiology Collaboration equation. RESULTS: Parenchymal thickness and renal length showed the highest correlation level with the GFR. This significant correlation, however, was greatly ameliorated by the correction for patients' body height (r = 0.537; P < .001; r = 0.510; P < .001, respectively). Of note, the product of these two parameters corrected for body height showed the best degree of correlation with the GFR (r = 0.560; P < .001), as confirmed by analysis of variance after subdivision of the population into CKD stage groups according to the GFR. Receiver operating characteristic curve analysis for discrimination of a GFR of less than 60 mL/min indentified the combined parameter as the one with the highest area under the curve (0.78; 95% confidence interval, 0.66-0.89), followed renal length corrected for height (area under the curve, 0.77; 95% confidence interval, 0.66-0.88). CONCLUSIONS: Correction of renal sonographic parameters for body height strengthens the degree of the correlation of renal sonography with the GFR. The improved correlation with the GFR makes renal sonography a reliable tool for a more complete assessment of patients with CKD.

An uncommon presentation of an uncommon nephropathy: the karyomegalic interstitial nephritis.

Karyomegalic interstitial nephritis (KIN) is a rare and certainly underdiagnosed nephropathy. It is characterized by a peculiar histological picture of interstitial nephritis associated with the presence of hyperchromatic, abnormally enlarged nuclei of tubular epithelial cells. KIN has an uncertain etiology, but should be suspected in young patients in the second or third decade of life presenting with progressive renal failure, proteinuria and/or hematuria and a history of recurrent respiratory infections. In these cases, the diagnosis should be suspected and confirmed by a renal biopsy. Herein, we report a case of KIN with atypical clinical presentation in a young patient with progressive kidney failure without proteinuria or hematuria or history of recurrent respiratory infections.

Early detection of progressive renal dysfunction in patients with coronary artery disease.

BACKGROUND: An association between renal hemodynamic dysfunction and coronary artery disease (CAD) has been documented in chronic renal failure; however, no information is available in CAD patients with normal glomerular filtration rate (GFR). This study was aimed at evaluating early abnormalities and outcome of renal function in CAD patients. METHODS: In 15 nondiabetic patients with normal renal function and no significant stenoses in renal arteries, and having undergone coronary arteriography, we studied systemic and renal hemodynamics before and after a vasodilating stimulus induced by aminoacid (AA) infusion. A control group (C) consisted of 15 sex- and age-matched kidney donors. The statistical adequacy of the sample size was preliminarily verified. Renal clearances were repeated after two years. RESULTS: At baseline, GFR (mL/min/1.73 m2) averaged 81.4 +/- 3.8 in CAD and 83.7 +/- 1.4 in C (P= NS); RPF (mL/min/1.73 m2) was 297 +/- 22 in CAD and 456 +/- 15 in C (P < 0.0001); filtration fraction was higher in CAD (P < 0.001). Plasma renin activity was higher in CAD (P < 0.005). The number of coronary stenoses was inversely correlated with RPF but not with GFR. In CAD, at variance with C, AA did not induce any increment of GFR, while RPF increased without achieving the unstimulated value of C. Blood pressure was comparable in CAD and C at baseline and not modified by AA. After two years, a significant decrease in GFR (-14%, P < 0.001) and RPF (-15%, P < 0.001) occurred only in CAD, and in either group, the response to AA did not differ from that detected at baseline. CONCLUSION: In CAD patients with normal GFR, reduction in renal perfusion and absence of renal functional reserve likely represent early markers of progressive renal dysfunction.

Can young adult patients with proteinuric IgA nephropathy perform physical exercise?

BACKGROUND: It is not known whether physical exercise increases daily proteinuria in patients with proteinuric nephropathies, thus accelerating progression of the renal lesion. This study evaluates the acute effects of physical exercise on proteinuria in young adults with immunoglobulin A (IgA) nephropathy. METHODS: Changes induced by intense physical exercise on quantitative and qualitative proteinuria were evaluated in basal conditions and after 10 days of ramipril therapy in 10 patients with IgA nephropathy, normal glomerular filtration rate (GFR), proteinuria between 0.8 and 1.49 g/24 h, and "glomerular" microhematuria before and after the end of a maximal treadmill Bruce test (B-test). The basal study also was performed in 10 age- and sex-matched healthy volunteers. RESULTS: At rest, GFR averaged 141 +/- 23 mL/min; it increased by 16.3% +/- 3.3% (P < 0.005) and 7.1% +/- 1.6% at 60 and 120 minutes after the B-test, respectively. At rest, GFR-corrected proteinuria averaged protein of 0.76 +/- 0.21 mg/min/100 mL GFR; it increased to 1.55 +/- 0.28 mg/min/100 mL GFR after 60 minutes (P < 0.001) and declined to 0.60 +/- 0.11 mg/min/100 mL GFR at 120 minutes after the end of the B-test. The pattern of urinary proteins remained unchanged, as did microhematuria. Daily proteinuria was not different from the basal value on the day of the B-test. After ramipril therapy, patients showed a reduction in GFR, but no change in daily GFR-corrected proteinuria, pattern of urinary proteins, or hematuria. CONCLUSION: The increase in proteinuria after exercise in our patients is significant and is not prevented by ramipril therapy, but lasts less than 120 minutes. Therefore, it cannot modify daily proteinuria. Thus, these data do not support the need to reduce acute physical activity in patients with nonnephrotic renal diseases.