The risks associated with percutaneous native kidney biopsies: a prospective study.

BACKGROUND: The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy. METHODS: The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression. RESULTS: Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08-1.17], liver disease (OR 2.27, 95% CI 1.21-4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07-1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92-0.99) were protective. CONCLUSIONS: This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

The genetic and clinical spectrum of a large cohort of patients with distal renal tubular acidosis.

Primary distal renal tubular acidosis is a rare genetic disease. Mutations in SLC4A1, ATP6V0A4, and ATP6V1B1 genes have been described as the cause of the disease, transmitted as either an autosomal dominant or recessive trait. Particular clinical features, such as sensorineural hearing loss, have been mainly described in association with mutations in one gene instead of the others. Nevertheless, the diagnosis of distal renal tubular acidosis is essentially based on clinical and laboratory findings, and the series of patients described so far are usually represented by small cohorts. Therefore, a strict genotype-phenotype correlation is still lacking, and questions about whether clinical and laboratory data should direct the genetic analysis remain open. Here, we applied next-generation sequencing in 89 patients with a clinical diagnosis of distal renal tubular acidosis, analyzing the prevalence of genetic defects in SLC4A1, ATP6V0A4, and ATP6V1B1 genes and the clinical phenotype. A genetic cause was determined in 71.9% of cases. In our group of sporadic cases, clinical features, including sensorineural hearing loss, are not specific indicators of the causal underlying gene. Mutations in the ATP6V0A4 gene are quite as frequent as mutations in ATP6V1B1 in patients with recessive disease. Chronic kidney disease was frequent in patients with a long history of the disease. Thus, our results suggest that when distal renal tubular acidosis is suspected, complete genetic testing could be considered, irrespective of the clinical phenotype of the patient.

Evaluation of the Impact of a New Synthetic Vitamin E-Bonded Membrane on the Hypo-Responsiveness to the Erythropoietin Therapy in Hemodialysis Patients: A Multicenter Study.

BACKGROUND: Oxidative stress has been related to hypo-response to erythropoiesis-stimulating agents (ESAs) in hemodialysis (HD) patients. The aim of this study was to verify whether vitamin E (ViE) on a synthetic polysulfone dialyzer can improve ESA responsiveness. METHODS: This controlled, multicenter study involved 93 HD patients on stable ESA therapy, who were randomized to either ViE-coated polysulfone dialyzer or to a low-flux synthetic dialyzer. The primary outcome measure was the change in ESA resistance index (ERI) from baseline. RESULTS: Mean ERI decreased in the ViE group by 1.45 IU/kg*g/dl and increased in the control group by 0.53 IU/kg*g/dl, with a mean difference of 1.98 IU/kg*g/dl (p = 0.001 after adjusting for baseline ERI, as foreseen by the study protocol). Baseline ERI was inversely related to its changes during follow-up only in the control group (R2 = 0.29). CONCLUSIONS: The ViE dialyzer can improve ESA response in HD patients. Changes in ERI during follow-up are independent from baseline ERI only in the ViE group. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=453442.

Early Change in Urine Protein as a Surrogate End Point in Studies of IgA Nephropathy: An Individual-Patient Meta-analysis.

BACKGROUND: The role of change in proteinuria as a surrogate end point for randomized trials in immunoglobulin A nephropathy (IgAN) has previously not been thoroughly evaluated. STUDY DESIGN: Individual patient-level meta-analysis. SETTING & POPULATION: Individual-patient data for 830 patients from 11 randomized trials evaluating 4 intervention types (renin-angiotensin system [RAS] blockade, fish oil, immunosuppression, and steroids) examining associations between changes in urine protein and clinical end points at the individual and trial levels. SELECTION CRITERIA FOR STUDIES: Randomized controlled trials of IgAN with measurements of proteinuria at baseline and a median of 9 (range, 5-12) months follow-up, with at least 1 further year of follow-up for the clinical outcome. PREDICTOR: 9-month change in proteinuria. OUTCOME: Doubling of serum creatinine level, end-stage renal disease, or death. RESULTS: Early decline in proteinuria at 9 months was associated with lower risk for the clinical outcome (HR per 50% reduction in proteinuria, 0.40; 95% CI, 0.32-0.48) and was consistent across studies. Proportions of treatment effect on the clinical outcome explained by early decline in proteinuria were estimated at 11% (95% CI, -19% to 41%) for RAS blockade and 29% (95% CI, 6% to 53%) for steroid therapy. The direction of the pooled treatment effect on early change in proteinuria was in accord with the direction of the treatment effect on the clinical outcome for steroids and RAS blockade. Trial-level analyses estimated that the slope for the regression line for the association of treatment effects on the clinical end points and for the treatment effect on proteinuria was 2.15 (95% Bayesian credible interval, 0.10-4.32). LIMITATIONS: Study population restricted to 11 trials, all having fewer than 200 patients each with a limited number of clinical events. CONCLUSIONS: Results of this analysis offer novel evidence supporting the use of an early reduction in proteinuria as a surrogate end point for clinical end points in IgAN in selected settings.

Phosphate levels in patients treated with low-flux haemodialysis, pre-dilution haemofiltration and haemodiafiltration: post hoc analysis of a multicentre, randomized and controlled trial.

BACKGROUND: Whether convective therapies allow better control of serum phosphate (P) is still undefined, and no data are available concerning on-line haemofiltration (HF). The objectives of the study are to evaluate the effect of convective treatments (CTs) on P levels in comparison with low-flux haemodialysis (HD) and to evaluate the correlates of serum phosphate in a post hoc analysis of a randomized clinical trial. METHODS: This analysis was performed in the database of a multicentre, open label and randomized controlled study in which 146 chronic HD patients from 27 Italian centres were randomly assigned to HD (70 patients) or CTs: on-line pre-dilution HF (36 patients) or on-line pre-dilution haemodiafiltration (40 patients). RESULTS: CTs did not affect P (P = 0.526), calcium (Ca) (P = 0.849) and parathyroid hormone levels (P = 0.622). P levels were associated with the use of phosphate binders including aluminium-based phosphate binders (P < 0.001) and sevelamer (P < 0.001), pre-dialysis bicarbonate levels (P < 0.001) and pre-dialysis blood K levels (P < 0.001). On multivariate analysis (generalized linear model), serum P was again largely unassociated with CTs (P = 0.631). Notably, participating centres were by far the strongest independent correlate of serum P, explaining 45.3% of the variance of serum P over the trial and this association was confirmed at multivariate analysis. Bicarbonate (P < 0.001) and, to a weaker extent, serum K (P = 0.032) were independently related to serum P. CONCLUSIONS: In comparison with low-flux HD, CTs did not significantly affect serum P levels. Participating centres were the main source of P variability during the trial followed by treatment with phosphate binders, serum bicarbonate and, to a weak extent, serum potassium levels (ClinicalTrials.gov Identifier: NCT011583309).

How histopathological diagnosis interacts with kidney ultrasound parameters and glomerular filtration rate.

The evaluation of estimated GFR (eGFR) is a pivotal staging step in patients with chronic kidney disease (CKD), and renal ultrasound plays an important role in diagnosis, prognosis and progression of CKD. The interaction between histopathological diagnosis and ultrasound parameters in eGFR determination has not been fully investigated yet. The study examined the results of native kidney biopsies performed in 48 Italian centers between 2012 and 2020. The primary goal was if and how the histopathological diagnosis influences the relationship between ultrasound parameters and eGFR. After exclusion of children, patients with acute kidney injury and patients without measure of kidney length or parenchymal thickness, 2795 patients have been selected for analysis. The median values were 52 years for patient age, 11 cm for bipolar kidney diameter, 16 mm for parenchymal thickness, 2.5 g/day for proteinuria and 70 ml/min/1.73 m2 for eGFR. The bipolar kidney diameter and the parenchymal thickness were directly related with eGFR values (R square 0.064). Diabetes and proteinuria were associated with a consistent reduction of eGFR, improving the adjusted R square up to 0.100. Addition of histopathological diagnosis in the model increased the adjusted R square to 0.216. There is a significant interaction between histopathological diagnosis and longitudinal kidney diameter (P 0.006). Renal bipolar length and parenchymal thickness are directly related with eGFR. The magnitude of proteinuria and histopathological kidney diagnosis are associated with eGFR. The relationship between kidney length and the level of eGFR depends on the nature of the kidney disease.

Central adrenal insufficiency in young adults with Prader-Willi syndrome.

OBJECTIVE: A high prevalence (60%) of central adrenal insufficiency (CAI) has been reported in Prader-Willi syndrome (PWS) using the metyrapone test. We have assessed CAI in adults with PWS using the low-dose short synacthen test (LDSST). DESIGN: Basal cortisol and ACTH, and 30-min cortisol after the administration of 1 µg synacthen, were determined in 53 PWS adults (33 females). A peak cortisol value of ≥500 nmol/l was taken as normal. Hormonal profiles were analysed in relation to gender, genotype and phenotype. Deficient patients were retested by high-dose short synachten test (HDSST) or a repeat LDSST. RESULTS: Mean ± SD basal cortisol and ACTH were 336·6 ± 140·7 nmol/l and 4·4 ± 3·7 pmol/l respectively. Cortisol rose to 615·4 ± 135·0 nmol/l after LDSST. Eight (15·1%) patients had a peak cortisol response <500 nmol/l, with a lower mean ± SD (range) basal cortisol of 184·9 ± 32·0 (138·0-231·7) compared with 364·1 ± 136·6 (149·0-744·5) in normal responders (P < 0·001). Seven of the eight patients underwent retesting, with 4 (7·5%) showing persistent suboptimal responses. Basal and peak cortisol correlated in females (r = 0·781, P < 0·001). Logistic regression revealed that only female gender and baseline cortisol were predictors of cortisol peaks (adjusted R square 0·505). CONCLUSIONS: Although CAI can be part of the adult PWS phenotype, it has a lower prevalence (7·5%) than previously reported. Clinicians are advised to test PWS patient for CAI. Our study also shows that basal cortisol is closely correlated with adrenal response to stimulation, indicating that its measurement may be helpful in selecting patients for LDSST.

Assessment of central adrenal insufficiency in children and adolescents with Prader-Willi syndrome.

OBJECTIVE: A recent study evidenced by metyrapone test a central adrenal insufficiency (CAI) in 60% of Prader-Willi syndrome (PWS) children. These results were not confirmed in investigations with low [Low-Dose Tetracosactrin Stimulation Test (LDTST), 1 µg] or standard-dose tetracosactrin stimulation tests. We extended the research by LDTST in paediatric patients with PWS. DESIGN: Cross-sectional evaluation of adrenal stress response to LDTST in a PWS cohort of a tertiary care referral centre. PATIENTS: Eighty-four children with PWS. MEASUREMENTS: Assessment of adrenal response by morning cortisol and ACTH dosage, and 1-µg tetracosactrin test. Response was considered appropriate when cortisol reached 500 nm; below this threshold, patients were submitted to a second test. Responses were correlated with the patients' clinical and molecular characteristics to assess genotype-phenotype correlation. RESULTS: Pathological cortisol peak responses to the LDTST were registered in 12 patients (14.3%) who had reduced basal (169.4 ± 83.3 nm) and stimulated (428.1 ± 69.6 nm) cortisol levels compared to patients with normal responses (367.1 ± 170.6 and 775.9 ± 191.3 nm, P < 0.001). Body mass index standard deviation score was negatively correlated with basal and peak cortisol levels (both P < 0.001), and the patients' ages (P < 0.001). In patients with deletion on chromosome 15, the cortisol peak was significantly lower than that in uniparental disomy (UPD) cases (P = 0.030). At multiple regression analysis, the predictors of peak response were basal cortisol, age, and UPD subclass (r(2) = 0.353, P < 0.001). Standard-dose (250 µg) tetracosactrin test confirmed CAI in 4/12 patients (4.8% of the cohort). CONCLUSIONS: Our results support the hypothesis that, albeit rare, CAI may be part of the PWS in childhood.

Predictors of haemoglobin levels and resistance to erythropoiesis-stimulating agents in patients treated with low-flux haemodialysis, haemofiltration and haemodiafiltration: results of a multicentre randomized and controlled trial.

BACKGROUND: Predictors of haemoglobin (Hb) levels and resistance to erythropoiesis-stimulating agents (ESAs) in dialysis patients have not yet been clearly defined. Some mainly uncontrolled studies suggest that online haemodiafiltration (HDF) may have a beneficial effect on Hb, whereas no data are available concerning online haemofiltration (HF). The objectives of this study were to evaluate the effects of convective treatments (CTs) on Hb levels and ESA resistance in comparison with low-flux haemodialysis (HD) and to evaluate the predictors of these outcomes. METHODS: Primary multivariate analysis was made of a pre-specified secondary outcome of a multicentre, open-label, randomized controlled study in which 146 chronic HD patients from 27 Italian centres were randomly assigned to HD (70 patients) or CTs: online pre-dilution HF (36 patients) or online pre-dilution HDF (40 patients). RESULTS: CTs did not affect Hb levels (P = 0.596) or ESA resistance (P = 0.984). Hb correlated with polycystic kidney disease (P = 0.001), C-reactive protein (P = 0.025), ferritin (P = 0.018), ESA dose (P < 0.001) and total cholesterol (P = 0.021). The participating centres were the main source of Hb variability (partial eta(2) 0.313, P < 0.001). ESA resistance directly correlated with serum ferritin (P = 0.030) and beta2 microglobulin (P = 0.065); participating centres were again a major source of variance (partial eta(2) 0.367, P < 0.001). Transferrin saturation did not predict either outcome variables (P = 0.277 and P = 0.170). CONCLUSIONS: In comparison with low-flux HD, CTs did not significantly improve Hb levels or ESA resistance. The main sources of variability were participating centres, ESA dose and the underlying disease.

Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study.

BACKGROUND: Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH. METHODS: Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH. RESULTS: Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 ± 3 versus 31 ± 4% of sessions, respectively, P l= l0.03), as was the per cent of clinical interventions (17 ± 3% of sessions with almost one intervention on HFR-Aeq versus 22 ± 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 ± 3% of sessions with hypotension on HFR-Aeq versus 71 ± 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq. CONCLUSIONS: HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na(+) measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.

Indication to renal biopsy in DM2 patients: potential role of intrarenal resistive index.

Diagnosis of diabetic nephropathy is generally based, rather than on histological confirmation, on clinical criteria (long history of diabetes, presence of proteinuria, diabetic retinopathy or peripheral neuropathy). This clinical approach has perhaps limited utility in DM2 patients, because only 50% of them show microvascular complications in presence of nephropathy. Eco-colour-Doppler sampling of interlobular renal arteries and determination of their resistance indices (RI), was proposed in the differential diagnosis of numerous nephropathies. Aim of this study was to evaluate whether RI can be useful in discerning non-diabetic renal disease (NDRD), in order to better define indications to perform renal biopsy among proteinuric DM2 patients. All patients were submitted to: echo-colour-Doppler study of renal vessels; systematic screening for diabetic retinopathy; needle renal biopsy. RI resulted to be significantly higher in diabetic glomerulosclerosis (GSD) group as compared with NDRD group, while no significant difference was found with respect to NDRDs overlapping GSD (overlapping group). The last one showed however median RI significantly higher than isolated NDRD group. Normalized chi square Pearson for the hypothesis that RI can predict GSD resulted 0.73, while it resulted 0.43 for the hypothesis that diabetic retinopathy can predict GSD. Echo-colour-Doppler can significantly contribute, more than the other parameters proposed (nephritic or nephrotic syndrome, hematuria, diabetic retinopathy), to the identification of underlying nephropathy in DM2 subjects. In the light of our experience, it seems that the detection of RI values > 0.72 suggests the diagnosis of GSD or mixed forms, reducing the indications to renal biopsy only in presence of values < 0.72.

[Therapeutic plasma exchange: a review of the literature]. / Aferesi ed evidenze in letteratura.

Therapeutic plasma exchange is an extracorporeal plasmapheresis method for removing high-molecular-weight pathogens and toxins from the circulation. It can be indicated in many clinical conditions, both kidney-related and non-kidney-related. This review focuses on clinical trials related to Goodpasture syndrome, thrombotic thrombocytopenic purpura, and acute renal insufficiency due to multiple myeloma. It also discusses the difficulties and opportunities associated with the development of a randomized controlled multicenter study and of a web-based database. Finally, we report a summary of the risks and complications of therapeutic plasma exchange and how we can update the information on their frequency and seriousness by means of a longitudinal prospective multicenter study open to all centers performing the procedure.

[Contrast enhanced ultrasound in renal diseases]. / L'imaging ecocontrastografico nella patologia renale.

Contrast-enhanced ultrasound (CEUS) is one of the most interesting and promising clinical applications of imaging and ultrasound. Thanks to the absence of ionizing radiation, the lack of nephrotoxicity and low cost it has the potential to become a reference in imaging of the kidney. This review, besides providing a brief description of the proper methodology, presents possible applications of CEUS in nephrology and urology, including renal ischemia, the differential diagnosis of cystic and solid lesions, follow-up of ablative therapies, kidney trauma, kidney transplant, inflammatory diseases, ischemic nephropathy and vesicoureteral reflux.

Diagnosis of acute pyelonephritis by contrast-enhanced ultrasonography in kidney transplant patients.

BACKGROUND: Diagnostic imaging of acute pyelonephritis (APN) in renal transplanted patients is an important clinical issue. While conventional ultrasonography (US) has a limited diagnostic role, contrast-enhanced computer tomography and magnetic resonance imaging (MRI) represent the gold standard diagnostic tests. However, nephrotoxicity of either iodinated or paramagnetic contrast medium limits their use, especially in patients with kidney disease. Contrast-enhanced US (CEUS) may detect poorly perfused parenchymal renal areas, a useful feature in the diagnosis of APN. The aim of this study was to evaluate the diagnostic value of CEUS in APN compared with MRI as the reference test. METHODS: From a pool of 389 kidney transplant patients, we prospectively recruited 56 patients with clinical suspicion of APN of the transplanted kidney. They underwent both CEUS and MRI, performed in a blinded manner by two different operators. Sensitivity, specificity, accuracy, positive and negative predictive values, and K statistics were calculated. RESULTS: Thirty-seven out of 56 patients (66.1%) resulted positive for APN with the reference test, gadolinium-enhanced MRI. Thirty-five out of these 37 patients showed positive results for APN with CEUS, and 19 patients showed negative results for APN with both MRI and CEUS: sensitivity 95% (CI 82-99), specificity 100% (CI 83-100), accuracy 96% (CI 88-99), positive predictive value 100% (CI 90-100), negative predictive value 90% (CI 71-97) and K statistics 0.92 (P<0.01). CONCLUSIONS: Our results suggest, for the first time, the feasibility of CEUS, a low-cost and low-risk diagnostic procedure, in the diagnosis of APN in kidney transplant patients.

Hemofiltration and hemodiafiltration reduce intradialytic hypotension in ESRD.

Symptomatic intradialytic hypotension is a common complication of hemodialysis (HD). The application of convective therapies to the outpatient setting may improve outcomes, including intradialytic hypotension. In this multicenter, open-label, randomized controlled study, we randomly assigned 146 long-term dialysis patients to HD (n = 70), online predilution hemofiltration (HF; n = 36), or online predilution hemodiafiltration (HDF; n = 40). The primary end point was the frequency of intradialytic symptomatic hypotension (ISH). Compared with the run-in period, the frequency of sessions with ISH during the evaluation period increased for HD (7.1 to 7.9%) and decreased for both HF (9.8 to 8.0%) and HDF (10.6 to 5.2%) (P < 0.001). Mean predialysis systolic BP increased by 4.2 mmHg among those who were assigned to HDF compared with decreases of 0.6 and 1.8 mmHg among those who were assigned to HD and HF, respectively (P = 0.038). Multivariate logistic regression demonstrated significant risk reductions in ISH for both HF (odds ratio 0.69; 95% confidence interval 0.51 to 0.92) and HDF (odds ratio 0.46, 95% confidence interval 0.33 to 0.63). There was a trend toward higher dropout for those who were assigned to HF (P = 0.107). In conclusion, compared with conventional HD, convective therapies (HDF and HF) reduce ISH in long-term dialysis patients.

Addition of azathioprine to corticosteroids does not benefit patients with IgA nephropathy.

The optimal treatment for IgA nephropathy (IgAN) remains unknown. Some patients respond to corticosteroids, suggesting that more aggressive treatment may provide additional benefit. We performed a randomized, multicenter, controlled trial to determine whether adding azathioprine to steroids improves renal outcome. We randomly assigned 207 IgAN patients with creatinine ≤2.0 mg/dl and proteinuria ≥1.0 g/d to either (1) a 3-day pulse of methylprednisolone in months 1, 3, and 5 in addition to both oral prednisone 0.5 mg/kg every other day and azathioprine 1.5 mg/kg per day for 6 months (n = 101, group 1) or (2) steroids alone on the same schedule (n = 106, group 2). The primary outcome was renal survival (time to 50% increase in plasma creatinine from baseline); secondary outcomes were changes in proteinuria over time and safety. After a median follow-up of 4.9 years, the primary endpoint occurred in 13 patients in group 1 (12.9%, 95% CI 7.5 to 20.9%) and 12 patients in group 2 (11.3%, CI 6.5 to 18.9%) (P = 0.83). Five-year cumulative renal survival was similar between groups (88 versus 89%; P = 0.83). Multivariate Cox regression analysis revealed that female gender, systolic BP, number of antihypertensive drugs, ACE inhibitor use, and proteinuria during follow-up predicted the risk of reaching the primary endpoint. Treatment significantly decreased proteinuria from 2.00 to 1.07 g/d during follow-up (P < 0.001) on average, with no difference between groups. Treatment-related adverse events were more frequent among those receiving azathioprine. In summary, adding low-dose azathioprine to corticosteroids for 6 months does not provide additional benefit to patients with IgAN and may increase the risk for adverse events.

Effect of synthetic vitamin E-bonded membrane on responsiveness to erythropoiesis-stimulating agents in hemodialysis patients: a pilot study.

BACKGROUND: Oxidative stress, a recently identified factor related to the response to erythropoiesis-stimulating agents (ESAs), is increased in hemodialysis patients. The aim of this study was to verify whether ESA responsiveness improves if the anti-oxidant vitamin E (Vi-E) is placed on the blood-side layer of a synthetic polysulfone (PS) dialyzer. METHODS: This 8-month, controlled and open randomized study involved 2 groups of patients on stable ESA therapy undergoing hemodialysis using a PS dialyzer with or without Vi-E treatment. Hemoglobin, albumin, high-sensitivity C-reactive protein, interleukin-6, iron status, parathyroid hormone (PTH), Vi-E (alpha- and gamma-tocopherol levels) and the oxidative stress markers, advanced oxidation protein products, carbonyls and advanced glycation end products were evaluated every 2 months. The primary outcome measure was ESA resistance, the weekly ESA dose divided by the product between hemoglobin level and end-dialysis body weight. RESULTS: Nineteen of the 20 randomized patients completed the study. During the follow-up, the ESA resistance significantly decreased (p = 0.024), greater in the Vi-E group (37%) than in the PS group (20%), but this difference was not statistically significant (p = 0.596). Baseline PTH and Vi-E levels were associated with ESA resistance. In the secondary analysis, including these covariates in the model, the difference between groups in ESA resistance became significant (p = 0.042). CONCLUSIONS: Vi-E placed on the blood-side of a dialyzer may have a possible beneficial effect on ESA resistance in hemodialysis patients; baseline PTH levels seem to predict ESA resistance and were useful in showing the possible beneficial effect of Vi-E and should be considered in designing adequate-sized trials for testing this hypothesis.

Persistent left superior vena cava: what the interventional nephrologist needs to know.

Variations in the course of the blood vessels are often incidental findings during clinical examination. Persistent left superior vena cava (PLSVC) is an uncommon anomaly, estimated to be present in about 0.3-0.5% of healthy individuals and in about 3-10% of patients with congenital heart disease. It results from the failure of the left anterior cardinal vein to degenerate during embryological development. Serious complications such as shock, angina and cardiac arrest have been described during catheterization in adults with a PLSVC. Since it frequently goes undiagnosed because of lack of symptoms when not accompanied by other anomalies, variations of the superior vena cava should be considered, especially when central venous catheterization via the subclavian or internal jugular vein is difficult. The embryological development, diagnosis, and clinical implications of a PLSVC are therefore reviewed in this article.

Predictors of first ischemic lower limb ulcer in dialysis patients: an observational cohort study.

BACKGROUND: Lower limb ischemia affects the quality of life, physical activity and life expectancy of dialysis patients. The aim of this study was to investigate the risk factors associated with ischemic foot ulcers considering clinical, laboratory and therapeutic domains. METHODS: This observational cohort study was based on data from the Nephrology and Dialysis Department database of Alessandro Manzoni Hospital, Lecco (Italy). All of the incident patients who started dialysis between 1 January 1999 and 29 February 2012 were enrolled, excluding temporary guests, patients with acute renal failure and patients with previous limb ischemia or amputation. Multivariate Cox regression analysis identified the predictors in each domain, which were matched in the final model. A time-dependent approach was used to take into account the evolution of some of the prognostic covariates. RESULTS: Of the 526 incident dialysis patients, 120 developed a lower limb ischemic lesion after a median of 13 months. The incidence of new ulcers was constant during the study period (6 per 100 person-years), but higher in the diabetics with a relative rate of 4.5. The variables significantly related to an increased risk of lower limb ulcers were age, male gender, diabetes, ischemic heart disease, treatment with proton pump inhibitors, iron, anticoagulants and calcium-based binders, and blood levels of phosphorus, triglycerides and C-reactive protein. CONCLUSION: The incidence of lower limb ulcers was highest during the early dialysis follow-up and was associated with, in addition to diabetes, modifiable laboratory and therapeutic predictors such as anticoagulants, proton pump inhibitors, calcium-containing binders, calcimimetics and iron.

Methotrexate versus cyclophosphamide for remission maintenance in ANCA-associated vasculitis: A randomised trial.

OBJECTIVES: The treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is based on remission-induction and remission-maintenance. Methotrexate is a widely used immunosuppressant but only a few studies explored its role for maintenance in AAV. This trial investigated the efficacy and safety of methotrexate as maintenance therapy for AAV. METHODS: In this single-centre, open-label, randomised trial we compared methotrexate and cyclophosphamide for maintenance in AAV. We enrolled patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA), the latter with poor-prognosis factors and/or peripheral neuropathy. Remission was induced with cyclophosphamide. At remission, the patients were randomised to receive methotrexate or to continue with cyclophosphamide for 12 months; after treatment, they were followed for another 12 months. The primary end-point was relapse; secondary end-points included renal outcomes and treatment-related toxicity. RESULTS: Of the 94 enrolled patients, 23 were excluded during remission-induction or did not achieve remission; the remaining 71 were randomised to cyclophosphamide (n = 33) or methotrexate (n = 38). Relapse frequencies at months 12 and 24 after randomisation were not different between the two groups (p = 1.00 and 1.00). Relapse-free survival was also comparable (log-rank test p = 0.99). No differences in relapses were detected between the two treatments when GPA+MPA and EGPA were analysed separately. There were no differences in eGFR at months 12 and 24; proteinuria declined significantly (from diagnosis to month 24) only in the cyclophosphamide group (p = 0.0007). No significant differences in adverse event frequencies were observed. CONCLUSIONS: MTX may be effective and safe for remission-maintenance in AAV. TRIAL REGISTRATION: clinicaltrials.gov NCT00751517.