Pre-gestational counselling for women living with CKD: starting from the bright side

Pregnancy in women living with chronic kidney disease (CKD) was often discouraged due to the risk of adverse maternal-fetal outcomes and the progression of kidney disease. This negative attitude has changed in recent years, with greater emphasis on patient empowerment than on the imperative 'non nocere'. Although risks persist, pregnancy outcomes even in advanced CKD have significantly improved, for both the mother and the newborn. Adequate counselling can help to minimize risks and support a more conscious and informed approach to those risks that are unavoidable. Pre-conception counselling enables a woman to plan the most appropriate moment for her to try to become pregnant. Counselling is context sensitive and needs to be discussed also within an ethical framework. Classically, counselling is more focused on risks than on the probability of a successful outcome. 'Positive counselling', highlighting also the chances of a favourable outcome, can help to strengthen the patient-physician relationship, which is a powerful means of optimizing adherence and compliance. Since, due to the heterogeneity of CKD, giving exact figures in single cases is difficult and may even be impossible, a scenario-based approach may help understanding and facing favourable outcomes and adverse events. Pregnancy outcomes modulate the future life of the mother and of her baby; hence the concept of 'post partum' counselling is also introduced, discussing how pregnancy results may modulate the long-term prognosis of the mother and the child and the future pregnancies.

Any reduction in maternal kidney mass makes a difference during pregnancy in gestational and fetal outcome

Little is known about the effect tubulointerstitial nephropathies have in modulating maternal-fetal outcomes in pregnancy. Therefore, we analyzed the main outcomes of pregnancy in these women to gain a better understanding of the role of a reduction in maternal kidney mass. From the Torino Cagliari Observational Study (TOCOS) cohort, we selected 529 patients with a diagnosis of tubulointerstitial disease and focused on 421 patients with chronic kidney disease (CKD) stage 1, without hypertension but with proteinuria less than 0.5 g/day at referral. From a cohort of 2969 singleton deliveries from low-risk pregnancies followed in the same settings we selected a propensity score matched control cohort of 842 pregnancies match 2:1 for age, parity, body mass index, ethnicity, and origin. Time to delivery was significantly shorter in the study cohort 38.0 (Quartile 1-Quartile 3: 37.0-39.0) versus 39.0 (Q1-Q3 38.0-40.0) weeks, with respect to controls. Incidence of delivery of less than 37 gestational weeks significantly increased from controls (7.4%) to women with previous acute pyelonephritis (10.8%), other tubulointerstitial diseases (9.7%) and was the highest in patients with a single kidney (31.1%). Similarly, neonatal birthweight significantly and progressively decreased from controls (3260 g [Q1-Q3: 2980-3530]), previous acute pyelonephritis (3090 g [Q1-Q3: 2868-3405], other tubulointerstitial diseases (3110 g [Q1-Q3: 2840-3417]), and to solitary kidney (2910 g [Q1-Q3: 2480-3240]). Risk of developing preeclampsia was significantly higher in the CKD cohort (3.6% vs 1.7% in low-risk controls). Thus, even a small reduction in functional kidney mass, such as a pyelonephritic scar, is associated with a shorter duration of pregnancy and an increased risk of preterm delivery. The risk is proportional to the extent of parenchymal reduction and is highest in cases with a solitary kidney.

Investigational new drugs for the treatment of chronic renal failure: an overview of the literature

INTRODUCTION

Chronic kidney disease (CKD) is widespread throughout the world, with a high social and health impact. It is considered a 'silent killer' for its sudden onset without symptoms in the early stages of the disease. The main goal of nephrologists is to slow the progression of kidney disease and treat the associated symptoms with a range of new medications.

AREAS COVERED

The aim of this systematic review is to analyze the new investigational drugs for the treatment of chronic renal failure. Data were obtained from the available scientific literature and from the ClinicalTrials.gov website.

EXPERT OPINION

Among the drugs currently being researched, SGLT2 inhibitors appear to be the most promising drugs for the treatment of CKD, has they have slower progression of CKD and protection of cardiorenal function. An important role in the future of CKD treatment is played by autologous cell-therapy, which appears to be a new frontier in the treatment of CKD. Other therapeutic strategies are currently being investigated and have been shown to slow the progression of CKD. However, further studies are needed to determine whether these approaches may offer benefits in slowing the progression of CKD in the near future.

Review and Practical Excursus of the Propensity Score: Low Protein Diet Compared to Mediterranean Diet in Patients With Chronic Kidney Disease

Although Randomized clinical trials (RCT) represent the gold standard to compare two or more treatments, the impact of observational studies cannot be ignored. Obviously, these latter are performed on unbalanced sample, and differences among the compared groups could be detected. These differences could have an impact on the estimated association between our allocation and our outcome. To avoid it, some methods should be applied in the analysis of observational cohort. Propensity score (PS) can be considered as a value which sums up and balances the known variables. It aims to adjust or balance the probability of receiving a specific allocation group, and could be used to match, stratify, weight, and perform a covariate adjustment. PS is calculated with a logistic regression, using allocation groups as the outcome. Thanks to PS, we compute the probability of being allocated to one group and we can match patients obtaining two balanced groups. It avoids computing analysis in unbalanced groups. We compared low protein diet (LPD) and the Mediterranean diet in CKD patients and analysed them using the PS methods. Nutritional therapy is fundamental for the prevention, progression and treatment of Chronic Kidney Disease (CKD) and its complications. An individualized, stepwise approach is essential to guarantee high adherence to nutritional patterns and to reach therapeutic goals. The best dietary regimen is still a matter of discussion. In our example, unbalanced analysis showed a significant renal function preservation in LPD, but this correlation was denied after the PS analysis. In conclusion, although unmatched analysis showed differences between the two diets, after propensity analysis no differences were detected. If RCT cannot be performed, balancing the PS score allows to balance the sample and avoids biased results.

Autoimmunity and Infection in Glomerular Disease

The ongoing glomerular damage of infections is not limited to the most widely known form of post-streptococcal glomerulonephritis, which is today less common in the Western world; other forms of glomerulonephritis are associated with several bacterial, viral and parasitic pathogens. The mechanisms responsible range from the direct damage of glomerular cells to the formation and deposition of immunocomplexes to molecular mimicry to the secretion of superantigens. Similarly, in the course of glomerular disease, infections are more frequent than in the general population due to the loss of immunoglobulins in urine and the immunosuppressive agents used to treat the autoimmune disease that decrease the activity of the immune system. Recognizing this two-way link, understanding its pathogenetic mechanism, and identifying the most appropriate therapeutic choice are essential for the personalized management of patients. In this continuously developing field, this short review summarizes the current state of the art as support for physicians, who are increasingly involved in managing patients with glomerular disease and infections.

Progress in pharmacotherapy for the treatment of hyperphosphatemia in renal failure

INTRODUCTION

Among the clinical and metabolic complications of progressive chronic kidney disease (CKD), CKD-mineral bone disorder (CKD-MBD) significantly contributes to morbidity and mortality. While overt and persistent hyperphosphatemia is typical of advanced CKD and requires treatment, other abnormalities of calcium/phosphate metabolism begin to occur since the early stages of the disease.

AREAS COVERED

We searched on the PubMed database, without restrictions for language or time range, for randomized clinical trials and meta-analyses investigating phosphate-lowering therapies. The various phosphate binders show different safety profiles and diverse effects on calcium/phosphate metabolism and vascular calcification. The in-depth knowledge of the characteristics of these drugs is crucial to ensure adequate treatment to CKD patients.

EXPERT OPINION

A proper control of serum phosphate can be achieved using phosphate binders. These medications may induce side effects. Moreover, data on their impact on clinical outcomes are partly controversial or scarce, especially for the new generation drugs. Hyperphosphatemia favors cardiovascular disease and increases the risk for CKD progression. These effects are partially mediated by fibroblast growth factor 23 (FGF23), a phosphaturic hormone that raises to maintain normal serum phosphate. Since there are no data supporting the use of phosphate-lowering agents when phosphataemia is normal, a key role is played by reducing dietary phosphate intake with the aim to control serum phosphate and the compensatory FGF23 and parathyroid hormone (PTH) increase.

Phosphate Control in Peritoneal Dialysis Patients: Issues, Solutions, and Open Questions

Hyperphosphatemia is a common complication in advanced chronic kidney disease and contributes to cardiovascular morbidity and mortality. The present narrative review focuses on the management of phosphatemia in uremic patients receiving peritoneal dialysis. These patients frequently develop hyperphosphatemia since phosphate anion behaves as a middle-size molecule despite its low molecular weight. Accordingly, patient transporter characteristics and peritoneal dialysis modalities and prescriptions remarkably influence serum phosphate control. Given that phosphate peritoneal removal is often insufficient, especially in lower transporters, patients are often prescribed phosphate binders whose use in peritoneal dialysis is primarily based on clinical trials conducted in hemodialysis because very few studies have been performed solely in peritoneal dialysis populations. A crucial role in phosphate control among peritoneal dialysis patients is played by diet, which must help in reducing phosphorous intake while preventing malnutrition. Moreover, residual renal function, which is preserved in most peritoneal dialysis patients, significantly contributes to maintaining phosphate balance. The inadequate serum phosphate control observed in many patients on peritoneal dialysis highlights the need for large and well-designed clinical trials including exclusively peritoneal dialysis patients to evaluate the effects of a multiple therapeutic approach on serum phosphate control and on hard clinical outcomes in this high-risk population.

Immune Checkpoint Inhibitors and the Kidney: A Focus on Diagnosis and Management for Personalised Medicine

Immunity plays a crucial role in fighting cancer, but tumours can evade the immune system and proliferate and metastasize. Enhancing immune responses is a new challenge in anticancer therapies. In this context, efficacy data are accumulating on immune checkpoint inhibitors and adjuvant therapies for various types of advanced-stage solid tumours. Unfortunately, immune-related adverse events are common. Although infrequent, renal toxicity may occur via several mechanisms and may require temporary or permanent drug suspension, renal biopsy, and/or immunosuppressive treatment. This short review aims to provide a practical approach to the multidisciplinary management of cancer patients with renal toxicity during treatment with immune checkpoint inhibitors.

Plant-based diets for CKD patients: fascinating, trendy, but feasible? A green nephrology perspective

Climate change is inducing us to rethink our way of life. There is widespread awareness that we need to adopt environmentally friendly approaches and reduce the amount of waste we generate. In medicine, nephrology was one of the first specialties to adopt a green approach. Plant-based or vegan-vegetarian diets, which are planet-friendly and associated with a reduced carbon footprint, were rapidly acknowledged as a valid method for reducing protein intake in the conservative management of chronic kidney disease (CKD). However, how the transition from an omnivorous to a plant-based diet should be managed is not universally agreed; there is little data in the literature and indications based on randomized trials fail to consider feasibility and patients' preferences. Nonetheless, in some conditions the use of plant-based diets has proved safe and effective. For example, in CKD pregnancies, it has reduced unfavorable maternal and fetal outcomes. This review will present the available evidence on the benefits of plant-based diets in CKD, as well as old and new criticisms of their use, including emerging issues, such as contaminants, additives and pesticides, from a green nephrology perspective.

Contactin 1, a Potential New Antigen Target in Membranous Nephropathy: A Case Report

Several novel antigens have recently been characterized in membranous nephropathy (MN), but those involved in the rare cases of MN associated with inflammatory neuropathies remain elusive. Although several antibodies have been identified in the serum, there is no evidence so far for their deposition in glomeruli. We report the case of a 73-year-old woman who was referred because of subacute onset of proximal asymmetric lower limb weakness together with ataxic gait. She was diagnosed with inflammatory neuropathy. Testing showed an estimated glomerular filtration rate of 73mL/min/1.73m², hypoalbuminemia (2.89g/dL), and proteinuria (3.6g/d). Autoantibodies (antinuclear antibody, anti-extractable nuclear antigen antibody, anti-double stranded DNA antibody, lupus anticoagulant, anticardiolipin antibody, antineutrophil cytoplasmic antibody) were undetectable. Serum immunoglobulin and complement levels were normal. A kidney biopsy with electron microscopy examination showed a classical picture of MN. Testing for antibodies to phospholipase A₂ receptor (PLA₂R) gave negative results in the serum, and PLA₂R and THSD7A antigens were not detected in kidney tissue. Anti-contactin 1 (CNTN1) antibody was detected by enzyme-linked immunosorbent assay at a 1:100 dilution of serum and shown to be mostly of IgG4 subclass by Western blot. CNTN1 antigen was colocalized with IgG4 within immune deposits by confocal microscopy. This observation suggests a pathophysiological link between inflammatory neuropathies and MN. CNTN1 should be considered as a potential candidate antigen involved in MN and tested in PLA₂R-negative forms associated with inflammatory neuropathies.

The Hypertensive Disorders of Pregnancy: A Focus on Definitions for Clinical Nephrologists

About 5-10% of pregnancies are complicated by one of the hypertensive disorders of pregnancy. The women who experience these disorders have a greater risk of having or developing kidney diseases than women with normotensive pregnancies. While international guidelines do not provide clear indications for a nephrology work-up after pregnancy, this is increasingly being advised by nephrology societies. The definitions of the hypertensive disorders of pregnancy have changed greatly in recent years. The objective of this short review is to gather and comment upon the main definitions of the hypertensive disorders of pregnancy as a support for nephrologists, who are increasingly involved in the short- and long-term management of women with these disorders.

MO577: The Role of Nutritional Therapy in CKD: Low Protein Diet VS Mediterranean Diet, A Multicentric Study

BACKGROUND AND AIMS

Nutritional therapy exerts a positive role for the prevention, progression and treatment of chronic kidney disease (CKD) and cardiovascular diseases. An individualized, stepwise approach is essential to guarantee high adherence to nutritional patterns and to reach therapeutical goals. Which is the best dietary regimen is still a matter of discussion.

METHOD

We performed an observational, multicentric study on 75 non-diabetic patients with CKD stage III-IV with a one-year follow-up (Table 1). We compared two of the most used dietary regimens for CKD patients: low protein diet (LPD) and the Mediterranean diet (MD).

RESULTS

Our results showed a significant renal function preservation in LPD compared with the MD cohort patients. An unadjusted model with a general linear model for repeated measures demonstrated a MD significant effect on creatinine clearance compared with LPD with an estimate marginal mean of −9.98 mL/min (95% CI: −15.6 to −4.3). Adjusted model for age, BMI and sex confirmed this significance in between-group in the joint mean difference (9.34, 95%CI: −15.44 to −3.24) (Fig. 1).

CONCLUSION

An adequate dietary strategy is of pivotal importance in the treatment of chronic diseases like CKD. Our study aimed to bring more evidence in the contest of nutritional therapy, demonstrating that beside the central importance of the MD for selected patients, LPD seems to have superior therapeutical benefits on kidney function preservation.

Gender differences in new hypoglycemic drug effects on renal outcomes: a systematic review

INTRODUCTION

Lifetime diabetes risk is greater in women than in men. Women with diabetes mellitus (DM) have a greater prevalence of diabetic kidney disease (DKD) risk factors. The diagnosis of DM is often delayed in women, with poorer outcomes and with expected therapeutic goals missed.

AREA COVERED

A systematic literature review following PRISMA guidelines was conducted in the PubMed gateway of the MEDLINE database and Clinicaltrials.gov. The purpose of our research was to establish the sex differences on renal outcomes in users of the new hypoglycemic drugs: sodium-glucose transport protein 2 inhibitors (SGLT-2i), dipeptidyl peptidase-IV Inhibitors (DPP-IVi) and glucagon-like peptide-1 inhibitors (GLP-1i).

EXPERT OPINION

New hypoglycemic drugs represent promising tools in the treatment and prevention of severe complications of diabetes, cardiovascular diseases and chronic kidney disease. Even if renal outcomes are investigated in both randomized controlled trials and cardiovascular outcome trials, gender-based analysis is not always performed. This may lead to relevant information for risk-benefit evaluation and therapeutic choices being missed, with gender-based equality in outcomes lacking. Our systematic review demonstrated that the gap among sexes in DKD can be partially filled using new hypoglycemic drugs. Sexual dimorphism analysis could represent a keystone for the development of adequate gender-specific therapies.

Indole-3-acetic acid correlates with monocyte-to-high-density lipoprotein (HDL) ratio (MHR) in chronic kidney disease patients

PURPOSE

Indole-3-acetic acid is a protein-bound indolic uremic toxin deriving from tryptophan metabolism. Increased levels are associated with higher thrombotic risk and both cardiovascular and all-cause mortality. An emerging biomarker of cardiovascular disease is the monocyte-to-high-density lipoprotein ratio (MHR). The main purpose of this study was to investigate the association of indole-3-acetic acid with MHR and other markers of cardiovascular risk in patients with chronic kidney disease (CKD).

METHODS

We enrolled 61 non-dialysis CKD patients and 6 dialysis patients. Indole-3-acetic acid levels were measured with ELISA technique.

RESULTS

In the whole cohort of 67 patients, indole-3-acetic acid was directly related to Ca × P (ρ = 0.256; P = 0.0365) and MHR (ρ = 0.321; P = 0.0082). In the 40 patients with previous cardiovascular events, indole-3-acetic acid correlated with uric acid (r = 0.3952; P = 0.0116) and MHR (ρ = 0.380; P = 0.0157). MHR was related with fibrinogen (ρ = 0.426; P = 0.0010), arterial hypertension (ρ = 0.274; P = 0.0251), C-reactive protein (ρ = 0.332; P = 0.0061), gender (ρ = - 0.375; P = 0.0017; 0 = male, 1 = female), and CKD stage (ρ = 0.260; P = 0.0337). A multiple regression analysis suggested that indole-3-acetic acid might be an independent predictor of MHR.

CONCLUSION

This study shows a significant association between indole-3-acetic acid and MHR. Prospective studies are required to evaluate if decreasing indole-3-acetic acid concentrations may reduce MHR levels and cardiovascular events and improve clinical outcomes.

Incremental and Personalized Hemodialysis Start: A New Standard of Care

Introduction

Incremental hemodialysis (iHD) may attenuate “dialysis shock” and reduce costs, preserving quality of life. It is considered difficult to reconcile with HD wards’ routine; fear of underdialysis and increasing mortality are additional concerns. The aim of this study was to evaluate mortality, morbidity, and costs in a large HD ward where iHD is the standard of HD start.

Methods

This observational study included all incident HD patients in 2017 to 2021, stratified according to HD start: iHD (1–2 sessions/wk), decremental HD (dHD, 3 sessions/wk at start, later reduced), or standard (3 sessions/wk). Results were compared with data recorded in the same unit before the incremental program (2015–2017) and with a propensity score-matched cohort from the French Renal Epidemiology and Information Network (REIN) registry.

Results

A total of 158 patients started HD in 2017 to 2021, 57.6% on iHD, 8.9% dHD, and 33.5% standard HD schedule. Patients on the standard schedule had lower initial estimated glomerular filtration rate (eGFR) (5 vs. 7 ml/min per 1.72 m², P = 0.003). We found no survival differences according to period of start (same center) and propensity score matching (REIN). Patients intensively followed in the pre-HD period were more likely to start on iHD-dHD. Persistence on iHD-dHD was about 50% at 1 year and 35% at 2 years. Hospitalization rates and time to first hospitalization or death did not differ between the schedules. The iHD-dHD policy allowed a 16% cost saving, even accounting for supplemental biochemical tests.

Conclusion

Our study reveals that iHD can be a new standard of care, as it is safe and feasible in up to two-thirds of patients on incident HD.

Hypernatraemia and low eGFR at hospitalization in COVID-19 patients: a deadly combination

Background

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on the general population and the burden of pre-existing comorbidities has heavily affected the outcome of the infection. Hyponatraemia has been frequently described. Conversely, hypernatraemia has rarely been described in COVID-19.

Methods

The studied cohort encompasses all COVID-19 patients consecutively admitted to the Messina Hospital, Italy, during the first wave of the epidemic. Since healthcare structures were not overwhelmed at that time, indications for hospitalization were homogeneous throughout the study period. Serum sodium levels, kidney function [estimated glomerular filtration rate (eGFR)], demographic and clinical characteristics were recorded at admission. Correlation between mortality, sodium and eGFR was evaluated by survival curves and univariate and multivariate regression models.

Results

Baseline biochemical and clinical data at the time of admission were available for 115 COVID-19-confirmed patients. The median age at admission was 73 years (48% men), with a median Charlson Comorbidity Index of 4. A total of 23.5% of patients presented with a sodium level ≥146 mmol/L, while 7.8% had sodium <135 mmol/L. Hypernatraemic patients were older, with higher comorbidity. Age, hypernatraemia and reduced eGFR were associated with increased mortality in both univariate and multivariate regression models (P < 0.001). The combination of hypernatraemia and reduced renal function at admission had an odds ratio of 47.67 (95% confidence interval 10.08–225.43) of dying compared with patients with an eGFR ≥60 mL/min and sodium <145 mmol/L.

Conclusions

Our study suggests that the association between hypernatraemia and reduced eGFR at referral is a highly relevant prognostic marker for death during hospitalization. The role of this association should be further tested in larger, multicentre cohorts.

Toward an individualized determination of dialysis adequacy: a narrative review with special emphasis on incremental hemodialysis

INTRODUCTION

The search for the 'perfect' renal replacement therapy has been paralleled by the search for the perfect biomarkers for assessing dialysis adequacy. Three main families of markers have been assessed: small molecules (prototype: urea); middle molecules (prototype β2-microglobulin); comprehensive and nutritional markers (prototype of the simplified assessment, albumin levels; composite indexes as malnutrition-inflammation score). After an era of standardization of dialysis treatment, personalized dialysis schedules are increasingly proposed, challenging the dogma of thrice-weekly hemodialysis.

AREAS COVERED

In this review, we describe the advantages and limitations of the approaches mentioned above, focusing on the open questions regarding personalized schedules and incremental hemodialysis.

EXPERT OPINION

In the era of personalized dialysis, the assessment of dialysis adequacy should be likewise personalized, due to the limits of 'one size fits all' approaches. We have tried to summarize some of the relevant issues regarding the determination of dialysis adequacy, attempting to adapt them to an elderly, highly comorbidity population, which would probably benefit from tailor-made dialysis prescriptions. While no single biomarker allows precisely tailoring the dialysis dose, we suggest using a combination of clinical and biological markers to prescribe dialysis according to comorbidity, life expectancy, residual kidney function, and small and medium-size molecule depuration.

Commonly used immunosuppressive drugs for kidney diseases and pregnancy: focus on open questions

Pregnancy is still a challenge in women with autoimmune diseases or kidney transplantation. In this context, management of the immunosuppressive therapy is critical, but, in spite of more than 60 years of experience, many issues remain open, also because of the difficulty in disentangling, in complex patients, the effect of the disease and of the frequent multiple treatments. For this purpose, we have tried to synthesize the existing knowledge and the unresolved issues, to support counseling and promote patient empowerment.

MO139INDOLE-3-ACETIC ACID CORRELATES WITH MONOCYTE TO HIGH-DENSITY LIPOPROTEIN (HDL) RATIO (MHR) IN CHRONIC KIDNEY DISEASE (CKD) PATIENTS AND MAY BE EFFICIENTLY REMOVED BY ACETATE-FREE BIOFILTRATION

Background and Aims

Indole-3-acetic acid (IAA, also called auxin) is a protein-bound indolic uremic toxin deriving from tryptophan metabolism by the intestinal bacteria. Previous studies have shown that increased IAA is associated with enhanced tissue factor synthesis in endothelial and peripheral blood mononuclear cells, oxidative stress and endothelial inflammation with resulting higher risk of thrombotic events and both cardiovascular and all-cause mortality. An emerging biomarker of cardiovascular disease is the monocyte to high-density lipoprotein (HDL) ratio (MHR). Its prognostic value is related to the ability of monocytes to release several cytokines involved in inflammation and atherogenesis and to the protective role of HDL through removal of cholesterol from peripheral tissues and suppression of both monocyte progenitor cell proliferation and differentiation and monocyte activation. In this single-centre cross-sectional observational study, we investigated the potential association of IAA with MHR and other markers of cardiovascular risk in a cohort of patients with CKD and evaluated the effect of a single midweek dialysis session with AFB (Acetate-free Biofiltration) technique on IAA serum concentrations.

Method

We enrolled 61 non-dialysis CKD adult patients and 6 dialysis patients treated with AFB technique. IAA levels were measured using an enzyme-linked immunosorbent assay (ELISA) kit (Cat. number abx150354; Abbexa Ltd, Cambridge, UK). Post-dialysis IAA levels were corrected for haemoconcentration.

Results

In the whole cohort of 67 patients, IAA was directly related to creatinine (ρ = 0.247; P = 0.0441), potassium (r = 0.2871; P = 0.0185), Ca x P product (ρ = 0.256; P = 0.0365) and MHR (ρ = 0.321; P = 0.0082).

After adjustment for creatinine, the correlation between IAA and potassium became not significant (r = 0.1968; P = 0.1133). Stratifying patients according to the history of cardiovascular disease, in the 40 patients with previous cardiovascular events IAA levels correlated significantly with uric acid (r = 0.3952; P = 0.0116) and MHR (ρ = 0.380; P = 0.0157).

In the remaining 27 patients without history of cardiovascular disease, IAA only correlated with potassium (r = 0.3912; P=0.0481) and, though borderline significantly, with creatinine (ρ = 0.349; P = 0.0805). To assess whether IAA would independently predict MHR values, we evaluated potential correlations of MHR with risk factors for cardiovascular disease. MHR was related with fibrinogen (ρ = 0.426; P = 0.0010), arterial hypertension (ρ = 0.274; P = 0.0251), C-reactive protein (ρ = 0.332; P = 0.0061), gender (ρ = -0.375; P = 0.0017; 0 = male, 1 = female), and CKD stage (ρ = 0.260; P = 0.0337). A multiple regression analysis identified IAA as an independent predictor of MHR. Lastly, IAA levels were higher in dialysis patients compared to non-dialysis CKD patients (97.44 ± 21.58 versus 65.08 ± 24.38 ng/ml respectively; P = 0.0026) and it was significantly removed by a single AFB session (97.44 ± 21.58 versus 54.59 ± 21.74 ng/ml; P = 0.0028) with a reduction ratio of 43.80 ± 17.47%.

Conclusion

This study shows a statistically significant association between IAA and MHR. Based on previous experimental studies, such relationship could be explained by the activation of the transcription factor aryl hydrocarbon receptor. Indeed, IAA is a potent ligand of aryl hydrocarbon receptor and the latter has proinflammatory and proatherogenic activities and can reduce HDL levels. Moreover, AFB efficiently removes IAA during a single dialysis session. Prospective studies with appropriate sample size and sufficiently long period of observation are required to evaluate if decreasing IAA levels, through targeted therapeutic strategies in non dialysis CKD patients or by optimization of dialysis techniques and prescriptions in patients receiving renal replacement therapy, may reduce MHR levels and cardiovascular events and improve clinical outcomes and survival.

Kidney Biopsy in Type 2 Diabetic Patients: Critical Reflections on Present Indications and Diagnostic Alternatives

Roughly 3% of patients worldwide with a new diagnosis of type 2 diabetes mellitus (T2DM) already have an overt nephropathy at diagnosis and about 20-30% of the remaining ones develop a complication of this kind later in life. The early identification of kidney disease in diabetic patients is important as it slows its progression, which is important not only because this reduces the need for renal replacement therapy, but also because it decreases the high rate of mortality and morbidity associated with a reduction in kidney function. The increasing prevalence of type 2 diabetes and the consequent greater probability of finding different types of kidney diseases in diabetic patients frequently gives rise to overlapping diagnoses, a definition encompassing the differential diagnosis between diabetic and non-diabetic kidney disease. The issue is made more complex by the acknowledgement of the increasing frequency of presentations of what is termed "diabetic kidney disease" without relevant proteinuria, in particular in T2DM patients. Distinguishing between diabetes related and non-diabetes related forms of kidney disease in diabetic patients is not only a semantic question, as different diseases require different clinical management. However, while the urologic and macrovascular complications of diabetes, as well as overlapping parenchymal damage, can be diagnosed by means of imaging studies, often only a kidney biopsy will make a differential diagnosis possible. In fact, the coexistence of typical diabetic lesions, such as nodular glomerulopathy or glomerulosclerosis, with different glomerular, vascular and tubulo-interstitial alterations has been extensively described, and an analysis of the dominant histological pattern can contribute to determining what therapeutic approach should be adopted. However, due to the high frequency of kidney diseases, and to the fact that T2DM patients are often affected by multiple comorbidities, a kidney biopsy is not generally performed in T2DM patients. What follows is a review aiming to discuss the diagnostic work-up, on the base of clinical, laboratory and imaging criteria, and evaluate the present indications and alternatives to renal biopsy.

Quality of Life in CKD Patients on Low-Protein Diets in a Multiple-Choice Diet System. Comparison between a French and an Italian Experience

Prescribing a low-protein diet (LPD) is part of the standard management of patients in advanced stages of chronic kidney disease (CKD). However, studies on the quality of life (QoL) of patients on LPDs are lacking, and the impact these diets have on their QoL is often given as a reason for not prescribing one. We, therefore, decided to assess the QoL in a cohort of CKD stage 3–5 patients followed up by a multiple-choice diet approach in an outpatient nephrology clinic in France. To do so, we used the short version of the World Health Organization’s quality of life questionnaire and compared the results with a historical cohort of Italian patients. We enrolled 153 patients, managed with tailored protein restriction in Le Mans, and compared them with 128 patients on similar diets who had been followed in Turin (Italy). We found there were no significant differences in terms of age (median 73 vs. 74 years, respectively), gender, CKD stage, and comorbidities (Charlson’s Comorbidity Index 7 vs. 6). French patients displayed a greater body mass index (29.0 vs. 25.4, p < 0.001) and prevalence of obesity (41.2 vs. 15.0%, p < 0.001). Baseline protein intake was over the target in France (1.2 g/kg of real body weight/day). In both cohorts, the burden of comorbidities was associated with poorer physical health perception while kidney function was inversely correlated to satisfaction with social life, independently of the type of diet. Our study suggests that the type of LPD they follow does not influence QoL in CKD patients and that a personalized approach towards protein restriction is feasible, even in elderly patients.

Antiproteinuric effect of DPP-IV inhibitors in diabetic and non-diabetic kidney diseases

Diabetes Mellitus (DM) is a chronic and severe metabolic disease, characterized by chronic hyperglycemia due to insulin resistance and/or reduced insulin secretion. Concerning the non-insulin glucose-lowering therapy for diabetes, Dipeptidyl-peptidase-4 (DPP-4) inhibitors, members of the incretin family, represent new agents, capable of a glycemic control improvement with an advantageous safety profile, given the absence of weight gain, the low incidence of hypoglycemia and the good renal tolerance in patients suffering from chronic renal failure. In addition to demonstrating efficacy in glycemic control through inhibition of GLP-1 degradation, DPP-4 inhibitors (DPP-4is) seem to demonstrate pleiotropic effects, which also make them interesting in both diabetic and non-diabetic nephropathies, especially for their capacity of reducing proteinuria. Several studies about diabetic nephropathy on patients' cohorts and murine models have demonstrated a solid direct relationship between DPP-4 activity and urinary albumin excretion (UAE), thus confirming the capacity of DPP-4is to reduce proteinuria; the mechanism responsible for that effect was studied to assess if it was the result of a direct action on renal impairment or a secondary consequence of the better glycemic control related to these agents. As a result of these more in-depth studies, DPP-4is have demonstrated an improvement of renal inflammation markers and consequent proteinuria reduction, regardless of glucose concentrations. Considering the nephroprotective effects of DPP-4is might be glycemic independent, several studies were conducted to prove the validity of the same effects in non-diabetic nephropathies. Among these studies, DPP-4is demonstrated an improvement of various renal inflammatory markers on several models of non-diabetes dependent renal impairment, confirming their capacity to reduce proteinuria, independently from the action on glucose metabolism. The objective of this review is to present and discuss the so far demonstrated antiproteinuric effect of DPP-4is and their effects on diabetic and non-diabetic nephropathies.

Pancreas transplantation inside Emilia-Romagna, Italy: referral pattern, demand forecasting, and organ availability

In Italy, referral of diabetic patients for pancreas transplantation (PT) is an unstructured process, resulting in a low rate of activity and late referrals, often when the patient has already undergone dialysis. In addition, the continuous improvement in pancreas transplant alone, offering the opportunity to reduce cardiovascular risk due to proteinuria and reduced glomerular filtration rate (GFR), is rarely appreciated. We therefore analyzed (1) referral activity to PT during the time frame 2001-2005 in Emilia-Romagna, Italy (four million inhabitants), by collecting ICD 9 CM codes (55.69 + 52.80; 52.86 and 52.80 alone) by residence of the patient; (2) demand for PT among a sample population of 1670 diabetes patients, whose charts were reviewed for the type of diabetes and presence of overt diabetic nephropathy (DN: proteinuria >300 mg/24 h and/or GFR <60 mL/min); (3) potential pancreas availability as the ratio between pancreas and hearts utilized (UP/HR) in different areas of our country. As a results, (1) referral activity reached 8.4 PT per million people in 5 years in the whole region, ranging from 2.6 in the province where a PT program is active, to a maximum value of 20.7 in the province where a devoted outpatient clinic is operated by nephrologists. (2) Prevalence of overt DN was 6% in our cohort, corresponding to 510 D1 patients worthy of evaluation for PT inside Emilia-Romagna region. (3) During 2006, UP/HR was 0.58 in Associazione Inter-Regionale Trapianti agency, 1.16 in Tuscany, 0.30 in Piedmont, and 0.26 in our region. Taken together, our data showed that (1) the referral of D1 to PT has to be empowered, keeping in touch with all patients suffering from diabetic nephropathy; (2) the outpatient clinic devoted to evaluation and recruitment of D1 with nephropathy plays the key role in this program of timely and widespread referral; (3) the availability of pancreata can be increased by utilizing broader criteria for harvesting, increased consent rate to donation and increased the demand for PT (recipient pool). Pancreas grafts need to increase, since the current low demand produces underutilization of the pancreas resource, due to the frequent lack of a suitable recipient.