Infections in lung transplanted patients: A review

Lung transplantation can improve the survival of patients with severe chronic pulmonary disorders. However, the short- and long-term risk of infections can increase morbidity and mortality rates. A non-systematic review was performed to provide the most updated information on pathogen, host, and environment-related factors associated with the occurrence of bacterial, fungal, and viral infections as well as the most appropriate therapeutic options. Bacterial infections account for about 50% of all infectious diseases in lung transplanted patients, while viruses represent the second cause of infection accounting for one third of all infections. Almost 10% of patients develop invasive fungal infections during the first year after lung transplant. Pre-transplantation comorbidities, disruption of physical barriers during the surgery, and exposure to nosocomial pathogens during the hospital stay are directly associated with the occurrence of life-threatening infections. Empiric antimicrobial treatment after the assessment of individual risk factors, local epidemiology of drug-resistant pathogens and possible drug-drug interactions can improve the clinical outcomes.

Personalized Low-Protein Diet Prescription in CKD Population: Merging Evidence From Randomized Trials With Observational Data

Nutritional therapy is a cornerstone of the clinical management of chronic kidney disease (CKD). Nevertheless, randomized controlled trials often have failed to show a relevant benefit of low-protein diets in nonselected CKD populations in terms of slowing the progression of kidney disease and need for dialysis. The more the target population is selected, the less the results can be generalizable to implement in clinical practice. On the contrary, observational studies, especially if performed with patient-centered, flexible approaches, point toward an extensive implementation of dietary protein restriction in different and unselected CKD populations. The observational evidence cannot be disregarded anymore. The most recent guidelines advise implementing low-protein diets or even very-low-protein diets in all CKD patients as early as stage 3. However, the lack of data from large randomized controlled trials on unselected CKD populations as well as on specific subpopulations, such as diabetic or obese patients, which nowadays comprise the majority of CKD subjects, reduces the generalizability of the recommendations. For some patient populations, such as those encompassing very old, nephrotic, or pregnant patients, the literature is even more limited because of the lower prevalence of these conditions and diffused prejudices against reducing protein intake. This pragmatic review discusses the need for integrating information derived from randomized trials with evidence derived from observational studies to guide feasible strategies for more successful implementation of low-protein diets in the treatment of all segments of the CKD population.

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.

The ABCs of personalized incremental dialysis start, Le Mans style

Thrice weekly hemodialysis (HD) is considered the standard of care for patients with end-stage chronic kidney disease (CKD) on extracorporeal renal replacement therapy. However, recent evidence has shown that up to one third of patients start dialysis with a residual kidney function that could allow a reduced frequency/dialysis dose. Interest towards HD schedules other than thrice weekly and the lessons learned from peritoneal dialysis, in addition to growing attention to patients' quality of life, have promoted renewed attention towards incremental HD (iHD). iHD comprises once and twice weekly schedules, makes it possible to soften the "dialysis shock" at the inception of therapy and is patient-friendly. Moreover, it might contribute to preserving residual kidney function longer. Nevertheless, iHD is performed differently in different settings and no guidelines exist on this subject. Taking advantage of the experience accrued with regard to the treatment of advanced CKD both in the outpatient clinic and in the dialysis unit in Le Mans, where two thirds of incident HD patients start in an incremental way, we aimed to present the practical aspects of iHD and discuss its advantages and drawbacks.

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.

Spontaneously Low Protein Intake in Elderly CKD Patients: Myth or Reality? Analysis of Baseline Protein Intake in a Large Cohort of Patients with Advanced CKD

The recent guidelines on nutritional management of chronic kidney disease (CKD) advise a reduction in protein intake as early as CKD stage 3, regardless of age, to slow kidney function impairment. However, since elderly patients are usually considered as having a spontaneously reduced protein intake, nutritional interventions to reduce protein intake are often considered futile. This study aimed to assess the baseline protein intake of elderly CKD patients referred for nephrology care, and explore the need for dietary evaluations, focusing on the current recommendations for protein restriction in CKD. This is an observational study of CKD patients followed in the unit dedicated to advanced CKD patients in Le Mans, France. Patients with stages 3 to 5 not on dialysis were included. All patients were evaluated by an expert dietician to assess their baseline protein intake, whenever possible on the basis of a 7-days diet journal; when this was not available, dietary recall or analysis of delivered meals was employed. Demographic characteristics, underlying kidney disease, Charlson Comorbidity Index (CCI), Malnutrition-Inflammation Score (MIS), Subjective Global Assessment (SGA) and clinical and laboratory data were recorded. Between 15 November 2017 and 31 December 2020, 436 patients were evaluated in the unit. Their age distribution was as follows: "young": <60 (n = 62), "young-old": 60-69 (n = 74), "old": 70-79 (n = 108), "old-old": 80-89 (n = 140) and "oldest-old": ≥90 (n = 54). The prevalence of vascular nephropathies was higher in patients older than 70 years compared to younger ones, as did CCI and MIS (p < 0.001). Moderate nutritional impairment (SGA: B) was higher in elderly patients, reaching 53.7% at ≥90, while less than 3% of patients in the overall cohort were classified as SGA C (p < 0.001). The median protein intake was higher than the recommended one of 0.8 g/kg/day in all age groups; it was 1.2 g/kg/day in younger patients and 1.0 thereafter (p < 0.001). Patient survival depended significantly on age (p < 0.001) but not on baseline protein intake (p = 0.63), and younger patients were more likely to start dialysis during follow-up (p < 0.001). Over half of the patients, including the old-old and oldest-old, were still on follow-up two years after referral and it was found that survival was only significantly associated with age and comorbidity and was not affected by baseline protein intake. Our study shows that most elderly patients, including old-old and extremely old CKD patients, are spontaneously on diets whose protein content is higher than recommended, and indicates there is a need for nutritional care for this population.

Unmet needs for CKD care: from the general population to the CKD clinics-how many patients are we missing?

Introduction

Prevalence of chronic kidney disease (CKD) varies around the world. Little is known about the discrepancy between the general population's needs and nephrology care offered. We aimed to contribute to filling this gap and propose a means to infer the number of patients needing follow-up.

Methods

All patients undergoing at least one nephrology consultation in 2019 were enrolled. We used the ratio between CKD Stages 3 and 4 reported in the literature, and considered that only 25–50% of CKD Stage 3 patients have progressive CKD, to hypothesize different scenarios to estimate the number of CKD Stage 3 patients still needing nephrology follow-up.

Results

The 1992 CKD patients were followed-up in our centre (56.93% males; age 66.71 ± 18.32 years; 16.82% Stage 1; 14.66% Stage 2; 39.46% Stage 3; 19.88% Stage 4; 7.68% Stage 5). The ratio between Stages 3 and 4 in population studies ranged from 7.72 to 51.29, being 1.98 in our centre. Hypothesizing that we followed-up 100, 70 or 50% of CKD Stage 4 patients, 528–2506 CKD Stage 3 patients in our area would need nephrology follow-up [1885–8946 per million population (p.m.p.)]. Three to 17 additional nephrologists p.m.p. would be necessary to fully cover the need for care.

Conclusions

The number of patients with CKD Stage 3 who would benefit from nephrology care is high. Considering that one patient-year of delay of dialysis could cover a nephrologist’s annual salary, interventions aimed to improve the care of advanced CKD may be economically sound.

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.

COVID-19 Vaccine Hesitancy in Patients on Dialysis in Italy and France

Introduction

Patients on dialysis (HDPs) are a category at high risk from COVID-19 and thus a high-priority group for vaccination. COVID-19 vaccine hesitancy has been a concern since the availability of the first vaccine. The objective of this study was to determine hesitancy rates and factors associated with hesitancy toward COVID-19 vaccination in HDP.

Methods

HDP were surveyed with an ad hoc questionnaire in 4 large dialysis facilities in Europe: Le Mans and Paris, in France, and Cagliari and Pavia, in Italy. The questionnaire explored different domains associated with vaccine hesitancy, such as perception of disease severity, sources of information about the vaccine and the disease, and confidence in the health care system.

Results

A total of 417 patients (average age 69 years, 60% men) agreed to answer the questionnaire. Hesitancy was associated with younger age (P = 0.003), lower perception of disease severity (P < 0.001) and vaccine efficacy (P < 0.001), and lower trust in vaccination (P < 0.001) and in the health care system and scientists (P < 0.001) in the univariate analysis. In the multivariate models, concerns about side effects (P = 0.004) and vaccine efficacy (P < 0.001) and living in France (P = 0.04) remained associated with higher vaccine hesitancy, whereas having received an influenza vaccine (P = 0.032) and trusting scientists (P = 0.032) were associated with a more positive attitude toward vaccination.

Conclusions

HDPs have a good understanding of the risks associated with COVID-19. Vaccine hesitancy was not associated with educational level, age, or gender but rather with lack of confidence in vaccine efficacy and concerns about safety. HDPs were quite skeptical about the health care system but generally trusted scientists.

Preeclampsia is a valuable opportunity to diagnose chronic kidney disease: a multicentre study

Background

Pre-eclampsia (PE) and chronic kidney disease (CKD) are known to be associated. Our objective was to assess the prevalence of CKD in a large multicentre cohort of women without acknowledged CKD who experienced a PE episode.

Methods

The setting for the study was France (Le Mans, Central France) and Italy (Cagliari, Sardinia). The study participants were patients who experienced PE in 2018–19, identified from the obstetric charts. Patients with known–acknowledged CKD were excluded. Only singletons were considered. Persistent (micro)albuminuria was defined as present and confirmed at least 3 months after delivery. CKD was defined according to the Kidney Disease Outcomes Quality Initiative guidelines; urinary alterations or low eGFR confirmed at a distance of at least 3 months, or morphologic changes. Patients were divided into four groups: evidence of CKD; no evidence of CKD; unclear diagnosis-ongoing work-up; or persistent microalbuminuria. The outcome ‘diagnosis of CKD’ was analysed by simple and multiple logistic regressions. Temporal series (week of delivery) were analysed with Kaplan–Meier curves and Cox analysis.

Results

Two hundred and eighty-two PE pregnancies were analysed (Le Mans: 162; Cagliari: 120). The incidence of CKD diagnosis was identical (Le Mans: 19.1%; Cagliari: 19.2%); no significant difference was found in unclear-ongoing diagnosis (6.2%; 5.8%) and microalbuminuria (10.5%; 5.8%). Glomerulonephritis and diabetic nephropathy were more frequent in Cagliari (higher age and diabetes prevalence), and interstitial diseases in Le Mans. In the multivariate logistic regression, CKD diagnosis was associated with preterm delivery (adjusted P = 0.035). Gestation was 1 week shorter in patients diagnosed with CKD (Kaplan–Meier P = 0.007). In Cox analysis, CKD remained associated with shorter gestation after adjustment for age and parity.

Conclusions

The prevalence of newly diagnosed CKD is high after PE (19% versus expected 3% in women of childbearing age), supporting a systematic nephrology work-up after PE.

MO1052GREEN DIALYSIS: FROM MITH TO FUTURE

Background and Aims

Over 2 million persons of the 7.8 billion world population undergo hemodialysis (HD). The need is underestimated because dialysis is not available free of charge for more of half of the word population. HD is costly process and produces a large quantity of medical waste. Reducing the environmental burden should be addressed as part of implementation dialysis programs.

While collaboration between physicians and several different professionals is needed to design and develop projects in this direction, these are lingering and the literature is still scant. We overviewed literature to frame what is in progress and find clues for development.

Method

We conducted a systematic review of the literature from 2000 searching in PubMed, Scopus, Web of Science, and Google Scholar using search keywords including dialysis, green, recycling, ecology. We retrieved 41 publications in medical and technological fields. The results were summarized in a narrative review.

Results

Facilities: the points on which attention is focused are the design of new buildings, whose project should encompass green solutions, including solar power and water conservation, to reduce long-term expenses and ensure an eco-friendly development.

Water: water consumption remains high, and the essential targets to improve efficiency are the optimization of the reverse osmosis system, and of the dialysate flow rate, and the waste-water management. The current idea is to substitute standard reverse osmosis, which have a high percent of waste-water, with recirculating systems. Likewise, lowering of dialysate flow rate could spare water consumption with no significant difference in term of efficiency. Moreover, different solutions have been proposed to reuse reject water: local sanitation, laundry departments, sterilization units within health facilities using redirected water, landscaping and irrigation.

Power: electricity needed per dialysis session is twice the average daily consumption of a family of four people. Use of renewable energies, as solar or wind power, has been proposed, and are occasionally applied to home HD. To date just one attempt has been made to recycling energy by using hydroturbine.

Disposable materials: most of dialysis disposables is made of plastic, over half of which is labeled as “potentially hazardous”. Only a minimal part of the plastic used in dialysis disposables is recyclable, both because of its composition and its assembly which makes in fact impossible the segregation of the different components. Present research regards bioplastics, new assembling techniques, alternative technologies of incineration, microwave treatment, alkaline hydrolysis, biological treatment and the new steam sterilize-then-shred system.

Dialysis machines: at the best of our knowledge there are no studies available about dialysis machine recycling.

Personnel education: the role of dialysis staff is essential in recycling and reusing materials as well as in correctly dividing contaminated and non-contaminated waste.

Conclusion

The development of sustainable buildings, devices and procedures requires a multidisciplinary approach: medical, chemical, biological, engineering; in addition producers contribution and government regulation are needed. Talking about these issues, involving specialists, spreading the concepts of planet friendly treatments, gives the opportunity to share ideas, experiences and turn them into relevant innovations. A good starting point could be data collection to identify critical issues and outline pragmatic operational possibilities to reduce consumption, increase reuse and recycle, involve and instruct health care personnel, integrate dialysis facilities in the environment they are built in.

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.

Electrical Impedance to Easily Discover Undeclared Freeze-thaw Cycles in Slaughtered Bovine Meat

A portable electrical impedance spectroscopy device was developed to monitor the bioimpedance resistive component of bovine meat by injecting a sinusoidal current of 1 mA at 65 kHz. Both right and left longissimus dorsi muscles were trimmed from 4 slaughtered cows. The left muscle portions were frozen to -18 °C for 7 days while the right ones were meantime maintained at 5 °C. Mean value of impedance per length (Ω/cm) of frozen and thawed left samples was 31% lower than that of right non-frozen one (P = 0.0001). It was concluded that the device is reliable for monitoring the maturation of beef meat in situ with the possibility of revealing undeclared freeze-thaw cycles.

Dietary satisfaction and quality of life in chronic kidney disease patients on low-protein diets: a multicentre study with long-term outcome data (TOrino-Pisa study)

BACKGROUND

Concerns about adherence and quality of life (QoL) limit the diffusion of low-protein diets (LPDs) as a way to slow chronic kidney disease (CKD) progression and postpone dialysis. The aim of this multicentre study is to assess dietary satisfaction in stable CKD patients.

METHODS

This was a multicentre cross-sectional study with long-term follow-up data. Prevalent patients on LPD for at least 6 months were selected in four Italian centres. QoL was assessed using the World Health Organization Quality of Life questionnaire, and diet satisfaction with the Modification of Diet in Renal Disease satisfaction questionnaire. Comorbidity was assessed by Charlson Comorbidity Index, estimated glomerular filtration rate (eGFR) was calculated by the CKD Epidemiology Collaboration equation and protein intake by Maroni-Mitch formula. Survival was analysed with Kaplan-Meier curves and Cox Proportional Hazard Model.

RESULTS

Four hundred and twenty-two CKD Stages 3-5 patients were enrolled. Over 95% were on moderately restricted diets (0.6 g/kg/day). Compliance was good (protein intake: 0.59 g/kg/day at baseline, 0.72 at the end of follow-up). Median dietary satisfaction was 4 on a 1-5 scale. QoL was not affected by the type of diet, but was influenced by age, comorbidity and setting of care. Two years later, at the end of follow-up, 66.6% of the patients were still on a diet; the main causes of discontinuation were dialysis and death. The dropout rate was low (5.5%); in Cox analysis, patient and renal survival were influenced by age and eGFR, but not by QoL, setting of care or type of diet.

CONCLUSIONS

LPDs are compatible with high dietary satisfaction and minimal dropout, at least in patients who are able to follow such a diet for at least 6 months.

Of Mice and Men: The Effect of Maternal Protein Restriction on Offspring's Kidney Health. Are Studies on Rodents Applicable to Chronic Kidney Disease Patients? A Narrative Review

In the almost 30 years that have passed since the postulation of the "Developmental Origins of Health and Disease" theory, it has been clearly demonstrated that a mother's dietary habits during pregnancy have potential consequences for her offspring that go far beyond in utero development. Protein malnutrition during pregnancy, for instance, can cause severe alterations ranging from intrauterine growth retardation to organ damage and increased susceptibility to hypertension, diabetes mellitus, cardiovascular diseases and chronic kidney disease (CKD) later in life both in experimental animals and humans. Conversely, a balanced mild protein restriction in patients affected by CKD has been shown to mitigate the biochemical derangements associated with kidney disease and even slow its progression. The first reports on the management of pregnant CKD women with a moderately protein-restricted plant-based diet appeared in the literature a few years ago. Today, this approach is still being debated, as is the optimal source of protein during gestation in CKD. The aim of this report is to critically review the available literature on the topic, focusing on the similarities and differences between animal and clinical studies.

New Intravenous Calcimimetic Agents: New Options, New Problems. An Example on How Clinical, Economical and Ethical Considerations Affect Choice of Treatment

BACKGROUND

Dialysis treatment is improving, but several long-term problems remain unsolved, including metabolic bone disease linked to chronic kidney disease (CKD-MBD). The availability of new, efficacious but expensive drugs (intravenous calcimimetic agents) poses ethical problems, especially in the setting of budget limitations.

METHODS

Reasons of choice, side effects, biochemical trends were discussed in a cohort of 15 patients (13% of the dialysis population) who stared treatment with intravenous calcimimetics in a single center. All patients had previously been treated with oral calcimimetic agents; dialysis efficacy was at target in 14/15; hemodiafiltration was employed in 10/15. Median Charlson Comorbidity Index was 8. The indications were discussed according to the principlist ethics (beneficience, non maleficience, justice and autonomy). Biochemical results were analyzed to support the clinical-ethical choices.

RESULTS

In the context of a strict clinical and biochemical surveillance, the lack of side effects ensured "non-maleficence"; efficacy was at least similar to oral calcimimetic agents, but tolerance was better. Autonomy was respected through a shared decision-making model; all patients appreciated the reduction of the drug burden, and most acknowledged better control of their biochemical data. The ethical conflict resides in the balance between the clinical "beneficience, non-maleficience" advantage and "justice" (economic impact of treatment, potentially in attrition with other resources, since the drug is expensive and included in the dialysis bundle). The dilemma is more relevant when a patient's life expectancy is short (economic impact without clear clinical advantages), or when non-compliance is an issue (unclear advantage if the whole treatment is not correctly taken).

CONCLUSIONS

In a context of person-centered medicine, autonomy, beneficence and non-maleficence should weight more than economic justice. While ethical discussions are not aimed at finding "the right answer" but asking "the right questions", this example can raise awareness of the importance of including an ethical analysis in the choice of "economically relevant" drugs.

Prescribing Hemodialysis or Hemodiafiltration: When One Size Does Not Fit All the Proposal of a Personalized Approach Based on Comorbidity and Nutritional Status

There is no simple way to prescribe hemodialysis. Changes in the dialysis population, improvements in dialysis techniques, and different attitudes towards the initiation of dialysis have influenced treatment goals and, consequently, dialysis prescription. However, in clinical practice prescription of dialysis still often follows a "one size fits all" rule, and there is no agreed distinction between treatment goals for the younger, lower-risk population, and for older, high comorbidity patients. In the younger dialysis population, efficiency is our main goal, as assessed by the demonstrated close relationship between depuration (tested by kinetic adequacy) and survival. In the ageing dialysis population, tolerance is probably a better objective: "good dialysis" should allow the patient to attain a stable metabolic balance with minimal dialysis-related morbidity. We would like therefore to open the discussion on a personalized approach to dialysis prescription, focused on efficiency in younger patients and on tolerance in older ones, based on life expectancy, comorbidity, residual kidney function, and nutritional status, with particular attention placed on elderly, high-comorbidity populations, such as the ones presently treated in most European centers. Prescription of dialysis includes reaching decisions on the following elements: dialysis modality (hemodialysis (HD) or hemodiafiltration (HDF)); type of membrane (permeability, surface); and the frequency and duration of sessions. Blood and dialysate flow, anticoagulation, and reinfusion (in HDF) are also briefly discussed. The approach described in this concept paper was developed considering the following items: nutritional markers and integrated scores (albumin, pre-albumin, cholesterol; body size, Body Mass Index (BMI), Malnutrition Inflammation Score (MIS), and Subjective Global Assessment (SGA)); life expectancy (age, comorbidity (Charlson Index), and dialysis vintage); kinetic goals (Kt/V, normalized protein catabolic rate (n-PCR), calcium phosphate, parathyroid hormone (PTH), beta-2 microglobulin); technical aspects including vascular access (fistula versus catheter, degree of functionality); residual kidney function and weight gain; and dialysis tolerance (intradialytic hypotension, post-dialysis fatigue, and subjective evaluation of the effect of dialysis on quality of life). In the era of personalized medicine, we hope the approach described in this concept paper, which requires validation but has the merit of providing innovation, may be a first step towards raising attention on this issue and will be of help in guiding dialysis choices that exploit the extraordinary potential of the present dialysis "menu".

Efficiency and nutritional parameters in an elderly high risk population on hemodialysis and hemodiafiltration in Italy and France: different treatments with similar names?

Background

Choice of dialysis is context sensitive, explored for PD and extracorporeal dialysis, but less studied for haemodialysis (HD) and hemodiafiltration (HDF), both widely employed in Italy and France; reasons of choice and differences in prescriptions may impact on dialysis-related variables, particularly relevant in elderly, high-comorbidity patients.

Methods

The study involved two high-comorbidity in-hospital cohorts, treated in Centers with similar characteristics, in Italy (Cagliari) and France (Le Mans). All patients (204) agreed to participate. Stable cases on thrice-weekly dialysis, with at least 2 months follow-up were selected (180 patients, Males 59.4%, median age 71 years, vintage 4.3 years, Charlson index 9). Univariate and multivariate correlations between baseline data, HD-HDF, dialysis efficiency and nutritional markers were assessed.

Results

In Le Mans HDF was mainly chosen to increase efficiency (large surface dialysers, high convective volume; 76.3% of the patients), in Cagliari to improve tolerance (smaller surfaces, lower convective volume; 59% of patients). Kt/V was similar in HD and HDF, and in both settings(median Kt/V Daugirdas 2: 1.6); in the setting of high efficiency no correlation was found between Kt/V, BMI, urea, creatinine, n-PCR and phosphate. The relationship between Kt/V and albumin was divergent: a weak consensual increase was present in Cagliari, a decrease in Le Mans, suggesting a role of albumin losses with high convective volumes. In the multivariate analysis, after adjustment for other covariates (including comorbidity and type of treatment) low albumin level < 3.5 g/dl was highly correlated with setting of study: Le Mans (OR: 7.155 (2.955–17.324)). The multivariate analysis confirmed a role of type of treatment, with higher risk of low albumin levels in HDF (OR: 3.592 (1.466–8.801)), and of comorbidity (Charlson index> = 7 (OR: 3.153 (1.311–7.582)), MIS index> = 7 (OR: 5.916 (2.457–14.241)).

Conclusions

The different prescriptions of HD and HDF may have similar effects on dialysis efficiency, but diverging effects on crucial nutritional markers, such as albumin levels, probably more evident in high-comorbidity populations.

A best practice position statement on the role of the nephrologist in the prevention and follow-up of preeclampsia: the Italian study group on kidney and pregnancy

Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.

The Diet and Haemodialysis Dyad: Three Eras, Four Open Questions and Four Paradoxes. A Narrative Review, Towards a Personalized, Patient-Centered Approach

The history of dialysis and diet can be viewed as a series of battles waged against potential threats to patients' lives. In the early years of dialysis, potassium was identified as "the killer", and the lists patients were given of forbidden foods included most plant-derived nourishment. As soon as dialysis became more efficient and survival increased, hyperphosphatemia, was identified as the enemy, generating an even longer list of banned aliments. Conversely, the "third era" finds us combating protein-energy wasting. This review discusses four questions and four paradoxes, regarding the diet-dialysis dyad: are the "magic numbers" of nutritional requirements (calories: 30-35 kcal/kg; proteins > 1.2 g/kg) still valid? Are the guidelines based on the metabolic needs of patients on "conventional" thrice-weekly bicarbonate dialysis applicable to different dialysis schedules, including daily dialysis or haemodiafiltration? The quantity of phosphate and potassium contained in processed and preserved foods may be significantly different from those in untreated foods: what are we eating? Is malnutrition one condition or a combination of conditions? The paradoxes: obesity is associated with higher survival in dialysis, losing weight is associated with mortality, but high BMI is a contraindication for kidney transplantation; it is difficult to limit phosphate intake when a patient is on a high-protein diet, such as the ones usually prescribed on dialysis; low serum albumin is associated with low dialysis efficiency and reduced survival, but on haemodiafiltration, high efficiency is coupled with albumin losses; banning plant derived food may limit consumption of "vascular healthy" food in a vulnerable population. Tailored approaches and agreed practices are needed so that we can identify attainable goals and pursue them in our fragile haemodialysis populations.