Iron biology

Iron is a fundamental element for biological life, starting from bacteria till humans. Iron is essential for cell function and survival, energy production and metabolism, whereas increased levels cause oxidative stress. It is also a constituent of haemoglobin and thus it is necessary for oxygen transportation through the body. Given these multiple functions, the regulation of iron metabolism is complex and tight coupled with oxygen homeostasis at tissue and cellular levels, thanks to the interaction with the hypoxia inducible factor (HIF) system. In patients with chronic kidney disease (CKD), iron deficiency significantly contributes to anaemia development. This frequently overlaps with chronic inflammation, causing iron- restricted erythropoiesis. To add further complexity, metabolic hyperferritinemia may, on one side, increase the risk for CKD and, on the other, overlaps with functional iron deficiency. Excessive intracellular iron in certain cell types during CKD can also mediate cellular death (called ferroptosis), and contribute to the pathogenesis of kidney damage, atherosclerosis and vascular calcifications. This review is aimed at broadening the perspective of iron metabolism in the setting of CKD not just as a contributor to anaemia in CKD patients, but also as an important player with an impact on cell metabolism, renal fibrosis, and the cardiovascular system.

Hypoxia-inducible factor prolyl hydroxylase inhibitors for anaemia in chronic kidney disease: a document by the European Renal Best Practice board of the European Renal Association

Anaemia is a common complication of chronic kidney disease (CKD) and is associated with poor long-term outcomes and quality of life. The use of supplemental iron, erythropoiesis stimulating agents (ESAs) and blood transfusions has been the mainstay of treatment of anaemia in CKD for more than three decades. Despite available treatments, CKD patients with anaemia are undertreated and moderate-to-severe anaemia remains prevalent in the CKD population. Anaemia has consistently been associated with greater mortality, hospitalisation, cardiovascular events, and CKD progression in patients with CKD, and the risk increases with anaemia severity. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitors have a novel mechanism of action by mimicking the body's response to hypoxia and have emerged as an alternative to ESAs for the treatment of anaemia in CKD. Their efficacy in correcting and maintaining haemoglobin has been demonstrated in over 30 phase 3 clinical trials. Additionally, HIF activation results in various pleiotropic effects beyond erythropoiesis with cholesterol reduction and improved iron homeostasis and potential anti-inflammatory effects. The long-term safety of these agents, particularly with respect to cardiovascular and thromboembolic events, and their possible effect on tumor growth requires to be fully elucidated. This document presents in detail the effects of HIF-PH inhibitors, describes their mechanisms of action and pharmacologic properties, and discusses their place in the treatment of anaemia in CKD according to the available evidence.

An update review of post-transplant diabetes mellitus: Concept, risk factors, clinical implications and management

OBJECTIVE

Kidney transplantation is the gold standard therapeutic alternative for patients with end-stage renal disease; nevertheless, it is not without potential complications leading to considerable morbidity and mortality such as post-transplant diabetes mellitus (PTDM). This narrative review aims to comprehensively evaluate PTDM in terms of its diagnostic approach, underlying pathophysiological pathways, epidemiological data, and management strategies.

METHODS

Articles were retrieved from electronic databases using predefined search terms. Inclusion criteria encompassed studies investigating PTDM diagnosis, pathophysiology, epidemiology, and management strategies.

RESULTS

PTDM emerges as a significant complication following kidney transplantation, influenced by various pathophysiological factors including peripheral insulin resistance, immunosuppressive medications, infections, and proinflammatory pathways. Despite discrepancies in prevalence estimates, PTDM poses substantial challenges to transplant. Diagnostic approaches, including traditional criteria such as fasting plasma glucose (FPG) and HbA1c, are limited in their ability to capture early PTDM manifestations. Oral glucose tolerance test (OGTT) emerges as a valuable tool, particularly in the early post-transplant period. Management strategies for PTDM remain unclear, within sufficient evidence from large-scale randomized clinical trials to guide optimal interventions. Nevertheless, glucose-lowering agents and life style modifications constitute primary modalities for managing hyperglycemia in transplant recipients.

DISCUSSION

The complex interplay between PTDM and the transplant process necessitates individualized diagnostic and management approaches. While early recognition and intervention are paramount, modifications to maintenance immunosuppressive regimens based solely on PTDM risk are not warranted, given the potential adverse consequences such as increased rejection risk. Further research is essential to refine management strategies and enhance outcomes for transplant recipients.

Kidney supportive care for advanced chronic and end-stage kidney disease: a retrospective cohort study

BACKGROUND

Kidney supportive care is an interdisciplinary model of person-centred medicine, suitable for patients with advanced Chronic Kidney Disease (CKD) and with End-Stage Kidney Disease (ESKD). There is little information on routine care, and palliative care remains poorly integrated into standard nephrology care. The aim of this study was to describe our experience in integrating a palliative care approach into the nephrology care of advanced chronic and end-stage kidney disease.

METHODS

A retrospective cohort study was conducted from 1 June, 2017 until 31 December, 2020 on 67 advanced CKD and ESKD patients admitted to a palliative care service.

RESULTS

The patients' median age was 83.6 years, 62.7% were male, 16.4% had CKD stage 4 and 83.6% stage 5. Almost half (47.8%) of the patients were on kidney replacement therapy, and 52.2% were on conservative therapy. The majority (77.6%) received home-based palliative care, 17.9% hospice care and 4.5% day-hospice care. The median number of nephrologists' visits per patient was 3.5. Access to palliative care specialists was set at 100% and the median number of palliative clinicians' visits was 8. Eighty-five percent of patients did not require hospitalisation and 94% did not access to the emergency room; 86.2% of the patients died in hospice or at home.

CONCLUSIONS

This study reports on the first steps taken to change practice in nephrology, by applying the Italian guideline for an integrated pathway of palliative care in nephrology. Nephrologists' and the palliative care team created a multi- and inter-disciplinary team, sharing their professional skills to support patients in hospice or at home.

Kidney and liver fat accumulation: from imaging to clinical consequences

BACKGROUND

Recent studies indicate that accumulation of adipose tissue in various organs such as liver and kidney may contribute to the pathophysiology of metabolic syndrome. We aim to investigate the association between kidney and liver adipose tissue accumulation, assessed by the magnetic resonance imaging (MRI) proton density fat fraction technique, along with its relation to clinical and biochemical parameters.

METHODS

We included 51 volunteers with phenotypical features of metabolic syndrome (mean age = 34 years, mean body-mass index = 26.4 kg/m2) in our study in which liver and kidney adipose tissue accumulation was assessed via MRI-proton density fat fraction along with multiple other clinical and biochemical parameters such as estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio, serum lipid profile, liver function tests and body-mass index (BMI).

RESULTS

Our results from the univariate linear regression analysis indicate that both the kidney and liver scores were positively correlated with markers such as BMI, urine albumin-to-creatinine ratio, triglycerides (p < 0.001) and negatively correlated with eGFR (p < 0.05). In multivariate analysis, urine albumin-to-creatinine ratio (p < 0.05), triglycerides (p < 0.01), eGFR (p < 0.05) and BMI (p < 0.001) were found to be independently associated with kidney and liver fat accumulation, respectively (R2 = 0.64; R2 = 0.89). There was also a positive correlation between kidney and liver fat accumulation.

CONCLUSION

We have found a significant association between adipose tissue accumulation in liver and kidney and the parameters of metabolic syndrome. Moreover, the presence of a strong association between kidney and liver fat accumulation and kidney function parameters such as urine albumin-to-creatinine ratio and eGFR may be an indicator of the clinical significance of parenchymal fat accumulation.

Angiopoietin as A Novel Prognostic Marker in Kidney Disease

Renal injury is among the leading causes of morbidity and mortality, however, there are no reliable indicators for determining the likelihood of developing CKD, CKD progression or AKI events. Vascular growth factors called angiopoietins have a role in endothelial function, vascular remodeling, tissue stabilization and inflammation, and have been implicated as prognostic and predictive markers in AKI. Although the exact mechanism of the relationship between kidney injury and angiopoietins is unknown, this review demonstrates that AKI patients have higher angiopoietin-2 levels and that higher angiopoietin-1 to angiopoietin-2 ratio may potentially be linked with a reduced risk of the chronic kidney disease progression. This review therefore emphasizes the importance of angiopoietin-2 and proposes that it could be an important predictor of AKI in clinical settings. There is a need for further large scale randomized clinical trials in order to have a better understanding of the significance of angiopoietin-2 and for the determination of its potential clinical implications.

Regional Citrate Anticoagulation: A Tale of More Than Two Stories

Calcium is a key clotting factor, and several inorganic molecules that bind to calcium have been found to reduce the clotting propensity of blood. Citrate, a calcium chelator, is used as inhibitor of the coagulation cascade in blood transfusion. Also, it is used as an anaticoagulant during dialysis to maintain patency of the extracorporeal circuit, known as regional citrate anticoagulation (RCA). The amount of citrate should be chosen such that ionized calcium concentrations in the extracorporeal circuit are reduced enough to minimize propagation of the coagulation cascade. The dialytic removal of the calcium-citrate complexes combined with reduced ionized calcium concentrations makes necessary calcium supplementation of the blood returning to the patient. This can be achieved in different ways. In classical RCA, citrate and calcium are infused in the afferent and efferent tubing, respectively, whereas the dialysate does not contain calcium. This setup has been shown to be highly efficacious with a very low clotting propensity. Strict monitoring of blood electrolytes is required. Alternatively, the use of a high-calcium dialysate leads to calcium loading, obviating the need for a separate calcium infusion pump. The main advantages are simplified delivery of RCA and less fluctuation of systemic calcium concentrations. Currently, citric acid is sometimes added to the acid concentrate as a replacement for acetic acid. Differences and similarities between RCA and citrate-containing dialysate are discussed. RCA is an excellent alternative to heparin for patients at high risk of bleeding. Semin Nephrol 36:x-xx © 20XX Elsevier Inc. All rights reserved.

Real-world usage of Chronic Kidney Disease - Mineral Bone Disorder (CKD-MBD) biomarkers in nephrology practices

Background

Chronic kidney disease mineral bone disorder (CKD-MBD) is a condition characterized by alterations of calcium, phosphate, parathyroid hormone (PTH), and fibroblast growth factor 23 (FGF-23) metabolism that in turn promote bone disorders, vascular calcifications, and increase cardiovascular (CV) risk. Nephrologists' awareness of diagnostic, prognostic, and therapeutic tools to manage CKD-MBD plays a primary role in adequately preventing and managing this condition in clinical practice.

Methods

A national survey (composed of 15 closed questions) was launched to inquire about the use of bone biomarkers in the management of CKD-MBD patients by nephrologists and to gain knowledge about the implementation of guideline recommendations in clinical practice.

Results

One hundred and six Italian nephrologists participated in the survey for an overall response rate of about 10%. Nephrologists indicated that the laboratories of their hospitals were able to satisfy request of ionized calcium levels, 105 (99.1%) of both PTH and alkaline phosphatase (ALP), 100 (94.3%) of 25(OH)D, and 61 (57.5%) of 1.25(OH)2D; while most laboratories did not support the requests of biomarkers such as FGF-23 (intact: 88.7% and c-terminal: 93.4%), Klotho (95.3%; soluble form: 97.2%), tartrate-resistant acid phosphatase 5b (TRAP-5b) (92.5%), C-terminal telopeptide (CTX) (71.7%), and pro-collagen type 1 N-terminal pro-peptide (P1NP) (88.7%). As interesting data regarding Italian nephrologists' behavior to start treatment of secondary hyperparathyroidism (sHPT), the majority of clinicians used KDOQI guidelines (n = 55, 51.9%). In contrast, only 40 nephrologists (37.7%) relied on KDIGO guidelines, which recommended referring to values of PTH between two and nine times the upper limit of the normal range.

Conclusion

Results point out a marked heterogeneity in the management of CKD-MBD by clinicians as well as a suboptimal implementation of guidelines in Italian clinical practice.

Klotho: a potential therapeutic target in aging and neurodegeneration beyond chronic kidney disease-a comprehensive review from the ERA CKD-MBD working group

Klotho, a multifunctional protein, acts as a co-receptor in fibroblast growth factor 23 and exerts its impact through various molecular pathways, including Wnt, hypoxia-inducible factor and insulin-like growth factor 1 pathways. The physiological significance of Klotho is the regulation of vitamin D and phosphate metabolism as well as serving as a vital component in aging and neurodegeneration. The role of Klotho in aging and neurodegeneration in particular has gained considerable attention. In this narrative review we highlight several key insights into the molecular basis and physiological function of Klotho and synthesize current research on the role of Klotho in neurodegeneration and aging. Klotho deficiency was associated with cognitive impairment, reduced growth, diminished longevity and the development of age-related diseases in vivo. Serum Klotho levels showed a decline in individuals with advanced age and those affected by chronic kidney disease, establishing its potential diagnostic significance. Additionally, multiple medications have been demonstrated to influence Klotho levels. Therefore, this comprehensive review suggests that Klotho could open the door to novel interventions aimed at addressing the challenges of aging and neurodegenerative disorders.

Third whole-brain radiation therapy for multiple brain metastases. Should it be considered in selected patients?

Whole brain reirradiation for the treatment of multiple brain metastases has shown promising results. However, concerns remain over the possible neurotoxic effects of the cumulative dose as well as the questionable radiosensitivity of recurrent metastases. A second reirradiation of the whole brain is ordinarily performed in our department for palliative purposes in patients presenting with multiple metastatic brain progression. For this study, an investigational third whole brain reirradiation has been administered to highly selected patients to obtain disease control and delay progression. Clinical outcomes and neurological toxicity were also evaluated.

Atherosclerotic renovascular disease: a clinical practice document by the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and the Working Group Hypertension and the Kidney of the European Society of Hypertension (ESH)

Atherosclerotic renovascular disease (ARVD) is the most common type of renal artery stenosis. It represents a common health problem with clinical presentations relevant to many medical specialties and carries a high risk for future cardiovascular and renal events, as well as overall mortality. The available evidence regarding the management of ARVD is conflicting. Randomized controlled trials failed to demonstrate superiority of percutaneous transluminal renal artery angioplasty (PTRA) with or without stenting in addition to standard medical therapy compared with medical therapy alone in lowering blood pressure levels or preventing adverse renal and cardiovascular outcomes in patients with ARVD, but they carried several limitations and met important criticism. Observational studies showed that PTRA is associated with future cardiorenal benefits in patients presenting with high-risk ARVD phenotypes (i.e. flash pulmonary oedema, resistant hypertension or rapid loss of kidney function). This clinical practice document, prepared by experts from the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and from the Working Group on Hypertension and the Kidney of the European Society of Hypertension (ESH), summarizes current knowledge in epidemiology, pathophysiology and diagnostic assessment of ARVD and presents, following a systematic literature review, key evidence relevant to treatment, with an aim to support clinicians in decision making and everyday management of patients with this condition.

Intrauterine life to adulthood: a potential risk factor for chronic kidney disease

Multiple risk factors for chronic kidney disease (CKD), one of the major causes of morbidity and mortality in the adult population globally, have been identified, including older age, male gender, family history, smoking, diabetes mellitus, hypertension, ischaemic heart diseases and various medications. Preterm delivery, affecting >10% of the newborns in the USA, is a global concern with increasing incidence in recent decades. Preterm birth has been linked to multiple medical comorbidities such as diabetes mellitus, hypertension and cardiovascular diseases, while its association with CKD has recently been investigated. Prematurity and intrauterine growth restriction (IUGR) have been associated with an increased risk for CKD, specific histopathological examination findings and CKD-associated risk factors such as diabetes mellitus, hypertension and dyslipidaemia. In this narrative review, our aim is to evaluate and summarize the association between the risk for CKD and prematurity, low birthweight and IUGR along with potential underlying pathophysiological mechanisms.

Mineralocorticoid receptor antagonist use in chronic kidney disease with type 2 diabetes: a clinical practice document by the European Renal Best Practice (ERBP) board of the European Renal Association (ERA)

Chronic kidney disease (CKD) in individuals with type 2 diabetes (T2D) represents a major public health issue; it develops in about 30%-40% of patients with diabetes mellitus and is the most common cause of CKD worldwide. Patients with CKD and T2D are at high risk of both developing kidney failure and of cardiovascular events. Renin-angiotensin system (RAS) blockers were considered the cornerstone of treatment of albuminuric CKD in T2D for more than 20 years. However, the residual risk of progression to more advanced CKD stages under RAS blockade remains high, while in major studies with these agents in patients with CKD and T2D no significant reductions in cardiovascular events and mortality were evident. Steroidal mineralocorticoid receptor antagonists (MRAs) are known to reduce albuminuria in individuals on RAS monotherapy, but their wide clinical use has been curtailed by the significant risk of hyperkalemia and absence of trials with hard renal outcomes. In recent years, non-steroidal MRAs have received increasing interest due to their better pharmacologic profile. Finerenone, the first compound of this class, was shown to effectively reduce the progression of kidney disease and of cardiovascular outcomes in participants with T2D in phase 3 trials. This clinical practice document prepared from a task force of the European Renal Best Practice board summarizes current knowledge on the role of MRAs in the treatment of CKD in T2D aiming to support clinicians in decision-making and everyday management of patients with this condition.

Early aging and premature vascular aging in chronic kidney disease

Aging is the progressive decline of body functions and a number of chronic conditions can lead to premature aging characterized by frailty, a diseased vasculature, osteoporosis, and muscle wasting. One of the major conditions associated with premature and accelerated aging is chronic kidney disease (CKD), which can also result in early vascular aging and the stiffening of the arteries. Premature vascular aging in CKD patients has been considered as a marker of prognosis of mortality and cardiovascular morbidity and therefore requires further attention. Oxidative stress, inflammation, advanced glycation end products, fructose, and an aberrant gut microbiota can contribute to the development of early aging in CKD patients. There are several key molecular pathways and molecules which play a role in aging and vascular aging including nuclear factor erythroid 2-related factor 2 (Nrf-2), AMP-activated protein kinase (AMPK), sirtuin 1 (SIRT1), and klotho. Potential therapeutic strategies can target these pathways. Future studies are needed to better understand the importance of premature aging and early vascular aging and to develop therapeutic alternatives for these conditions.

Association between CKD-MBD and mortality in older patients with advanced CKD-results from the EQUAL study

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a common complication of CKD; it is associated with higher mortality in dialysis patients, while its impact in non-dialysis patients remains mostly unknown. We investigated the associations between parathyroid hormone (PTH), phosphate and calcium (and their interactions), and all-cause, cardiovascular (CV) and non-CV mortality in older non-dialysis patients with advanced CKD.

METHODS

We used data from the European Quality study, which includes patients aged ≥65 years with estimated glomerular filtration rate ≤20 mL/min/1.73 m2 from six European countries. Sequentially adjusted Cox models were used to assess the association between baseline and time-dependent CKD-MBD biomarkers and all-cause, CV and non-CV mortality. Effect modification between biomarkers was also assessed.

RESULTS

In 1294 patients, the prevalence of CKD-MBD at baseline was 94%. Both PTH [adjusted hazard ratio (aHR) 1.12, 95% confidence interval (CI) 1.03-1.23, P = .01] and phosphate (aHR 1.35, 95% CI 1.00-1.84, P = .05), but not calcium (aHR 1.11, 95% CI 0.57-2.17, P = .76), were associated with all-cause mortality. Calcium was not independently associated with mortality, but modified the effect of phosphate, with the highest mortality risk found in patients with both hypercalcemia and hyperphosphatemia. PTH level was associated with CV mortality, but not with non-CV mortality, whereas phosphate was associated with both CV and non-CV mortality in most models.

CONCLUSIONS

CKD-MBD is very common in older non-dialysis patients with advanced CKD. PTH and phosphate are independently associated with all-cause mortality in this population. While PTH level is only associated with CV mortality, phosphate seems to be associated with both CV and non-CV mortality.

SGLT2i for evidence-based cardiorenal protection in diabetic and non-diabetic chronic kidney disease: a comprehensive review by EURECA-m and ERBP working groups of ERA

Chronic kidney disease (CKD) is a major public health issue affecting an estimated 850 million people globally. The leading causes of CKD is diabetes and hypertension, which together account for >50% of patients with end-stage kidney disease. Progressive CKD leads to the requirement for kidney replacement therapy with transplantation or dialysis. In addition, CKD, is a risk factor for premature cardiovascular disease, particularly from structural heart disease and heart failure (HF). Until 2015, the mainstay of treatment to slow progression of both diabetic and many non-diabetic kidney diseases was blood pressure control and renin-angiotensin system inhibition; however, neither angiotensin-converting enzyme inhibitors (ACEIs) nor angiotensin receptor blockers (ARBs) reduced cardiovascular events and mortality in major trials in CKD. The emergence of cardiovascular and renal benefits observed with sodium-glucose cotransporter-2 inhibitors (SGLT2i) from clinical trials of their use as anti-hyperglycaemic agents has led to a revolution in cardiorenal protection for patients with diabetes. Subsequent clinical trials, notably DAPA-HF, EMPEROR, CREDENCE, DAPA-CKD and EMPA-KIDNEY have demonstrated their benefits in reducing risk of HF and progression to kidney failure in patients with HF and/or CKD. The cardiorenal benefits-on a relative scale-appear similar in patients with or without diabetes. Specialty societies' guidelines are continually adapting as trial data emerges to support increasingly wide use of SGLT2i. This consensus paper from EURECA-m and ERBP highlights the latest evidence and summarizes the guidelines for use of SGLT2i for cardiorenal protection focusing on benefits observed relevant to people with CKD.

The open system of FGF-23 at the crossroad between additional P-lowering therapy, anemia and inflammation: how to deal with the intact and the C-terminal assays?

Fibroblast growth factor 23 (FGF-23) has been associated with increased cardiovascular risk and poor survival in dialysis patients. It is well established that FGF-23 synthesis is directly induced by positive phosphate (P) balance. On the other hand, P-lowering treatments such as nutritional P restriction, P binders and dialysis are capable of reducing FGF-23 levels. However, there are many uncertainties regarding the possibility of adopting FGF-23 to guide the clinical decision-making process in the context of chronic kidney disease-mineral bone disorder (CKD-MBD). Furthermore, the best assay to adopt for measurement of FGF-23 levels (namely the intact vs the C-terminal one) remains to be determined, especially in conditions capable of altering the synthesis as well as the cleavage of the intact and biologically active molecule, as occurs in the presence of CKD and its complications. This Editorial discusses the main insights provided by the post hoc analysis of the NOPHOS trial, with particular attention given to evidence-based peculiarities of the intact and the C-terminal assays available for measuring FGF-23 levels, especially in patients receiving additive P-lowering therapy in the presence of inflammation, anemia and iron deficiency.

Extracorporeal Techniques in Kidney Failure

During the last decades, various strategies have been optimized to enhance clearance of a variable spectrum of retained molecules to ensure hemodynamic tolerance to fluid removal and improve long-term survival in patients affected by kidney failure. Treatment effects are the result of the interaction of individual patient characteristics with device characteristics and treatment prescription. Historically, the nephrology community aimed to provide adequate treatment, along with the best possible quality of life and outcomes. In this article, we analyzed blood purification techniques that have been developed with their different characteristics.

Future treatment of vascular calcification in chronic kidney disease

INTRODUCTION

Cardiovascular disease (CVD) is one of the global leading causes of morbidity and mortality in chronic kidney disease (CKD) patients. Vascular calcification (VC) is a major cause of CVD in this population and is the consequence of complex interactions between inhibitor and promoter factors leading to pathological deposition of calcium and phosphate in soft tissues. Different pathological landscapes are associated with the development of VC, such as endothelial dysfunction, oxidative stress, chronic inflammation, loss of mineralization inhibitors, release of calcifying extracellular vesicles (cEVs) and circulating calcifying cells.

AREAS COVERED

In this review, we examined the literature and summarized the pathophysiology, biomarkers and focused on the treatments of VC.

EXPERT OPINION

Even though there is no consensus regarding specific treatment options, we provide the currently available treatment strategies that focus on phosphate balance, correction of vitamin D and vitamin K deficiencies, avoidance of both extremes of bone turnover, normalizing calcium levels and reduction of inflammatory response and the potential and promising therapeutic approaches liketargeting cellular mechanisms of calcification (e.g. SNF472, TNAP inhibitors).Creating novel scores to detect in advance VC and implementing targeted therapies is crucial to treat them and improve the future management of these patients.

The impact of vascular access type on survival in haemodialysis: time for a paradigm shift? A prospective cohort study

INTRODUCTION

Although arteriovenous autologous fistula is the vascular access of choice due to better long-term outcome than central venous catheters, the use of central venous catheters is increasing. Our study aims to describe the survival and epidemiological features of a cohort of dialysis patients with a focus on the role of vascular access.

METHODS

Our study comprises a follow-up period from 2001 to 2020 in a single center. Descriptive analysis was performed on baseline data. Moreover, we analysed predictive variables of death with univariable and multivariable logistic regressions. Predictors of survival were analysed by univariable and multivariable Cox regression.

RESULTS

Our analysis includes 754 patients undergoing chronic haemodialysis. In the multivariable logistic regression, the use of tunnelled catheters resulted protective against death from any cause (Odds Ratio 0.43; p = 0.017). In the multivariable Cox analysis, being "late referral" was associated with decreased survival in the first 6 months since haemodialysis start (Hazard Ratio 3.79; p = 0.001). In the subgroup of elderly (age ≥ 75 years) patients (n = 201/472) with a follow up of 7-60 months, multivariable logistic regression showed that tunnelled catheters at the start of haemodialysis were associated with lower mortality (Odds Ratio, 0.25; p = 0.021), whereas vascular disease was found to be the main risk factor for death (Odds Ratio, 5.11; p = 0.000). Moreover, vascular disease was confirmed as the only independent risk factor by Cox analysis (Hazard Ratio, 1.58; p = 0.017).

CONCLUSIONS

In our cohort, mortality was found to be more closely associated with comorbidities than with the type of vascular access. Tunnelled central venous catheters might be a viable option for haemodialysis patients.

Dialysis in Pregnancy: An Update Review

Chronic kidney disease and end-stage kidney disease (ESKD) are important public health problems with increased rates of morbidity, mortality, and social costs. Pregnancy is rare in patients with ESKD, with reduced fertility rates in women undergoing dialysis. Although current advances have led to an increase in live births in pregnant dialysis patients, this modality still has an increased risk of multiple adverse events in pregnant women. Despite these existing risks, large-scale studies investigating the management of pregnant women on dialysis are lacking, resulting in the absence of consensus guidelines for this patient group. In this review, we aimed to present the effects of dialysis during pregnancy. We first discuss pregnancy outcomes in dialysis patients and the development of acute kidney injury during pregnancy. Then, we discuss our recommendations for the management of pregnant dialysis patients, including the maintenance of pre-dialysis blood urea nitrogen levels, the ideal frequency and duration of hemodialysis sessions, as well as the modality of renal replacement therapies, the difficulty of maintaining peritoneal dialysis in the third trimester of pregnancy, and optimization of prepregnancy modifiable risk factors. Finally, we present our recommendations for future studies investigating dialysis among pregnant patients.

Choice of the Dialysis Modality: Practical Considerations

Chronic kidney disease and the need for kidney replacement therapy have increased dramatically in recent decades. Forecasts for the coming years predict an even greater increase, especially in low- and middle-income countries, due to the rise in metabolic and cardiovascular diseases and the aging population. Access to kidney replacement treatments may not be available to all patients, making it especially strategic to set up therapy programs that can ensure the best possible treatment for the greatest number of patients. The choice of the "ideal" kidney replacement therapy often conflicts with medical availability and the patient's tolerance. This paper discusses the pros and cons of various kidney replacement therapy options and their real-world applicability limits.

[Nephrological nutritional office: a transversal organization model and access flowchart]

The nutritional aspect has a critical relevance in the educational and care path of nephropathic patients. The Nephrology-Dietology synergy in the Hospital is conditioned by various factors, such as the difficulty for Dietology to provide capillary and personalized follow-up to nephropathic patients. Hence the experience of a transversal II level nephrological clinic, dedicated to nutritional aspects throughout the path of nephropathic patients, from the earliest stages of kidney disease to replacement treatment. The access flowchart provides a nephrological indication: from chronic kidney disease (CKD), kidney stones, immunopathology, hemodialysis, peritoneal dialysis, and transplantation clinics, from the nephrological department, patients are selected for evaluation. The clinic is conducted by an expert nephrologist and trained dietitians, and is divided into different settings: educational meetings in small groups (patients and caregivers); simultaneous dietary and nephrological visits to advanced CKD; nutritional-nephrological visits on specific problems: from metabolic screening of kidney stones to action on the intestinal microbiota in immunological pathologies, to the application of the ketogenic diet in obesity, metabolic syndrome, diabetes, and early kidney damage, to onconephrology. Submission to further dietological assessment is limited to critical and selected cases. The synergistic model between nephrology and dietetics offers clinical and organizational advantages: guarantees a capillary follow-up, reduces the number of hospital accesses, thus enhancing compliance and clinical outcomes, optimizes available resources, and overcomes the critical issues of a complex hospital with the advantage of the always profitable multidisciplinarity.

Vitamin D in SARS-CoV-2 patients with non-invasive ventilation support

BACKGROUND

Vitamin D (VitD) deficiency has been reported to be associated with respiratory tract infection. In this work we evaluated the concentration of VitD in COVID-19 patients experiencing acute respiratory infections of different levels of severity excluding those who underwent invasive respiratory support.

METHODS

The levels of serum VitD and C-reactive protein (CRP) were analyzed in 118 consecutive hospitalized COVID-19 patients (74 male, 44 female), confirmed with rRT-PCR. Of these patients with ventilation support 52 (44.1%) received oxygen via nasal cannula, oxygen mask or an oxygen mask with a reservoir, 48 (40.7%) were on a continuous positive airway pressure device (CPAP) and 18 (15,3%) on non-invasive mechanical ventilation (NIMV).

RESULTS

The median values (range) of VitD and of CRP were 15.1 ng/mL (1.3-73.3) and 14.2 mg/L (5.0-151.2), respectively. A negative correlation from VitD levels and those of CRP (correlation coefficient: 0.259: P=0.005) was observed. VitD levels in O<inf>2</inf> support patients were significantly higher than in both CPAP and NIMV patients. No statistical differences were found for CRP levels (P=0.834) among the three type of oxygen support. Fewer patients with O<inf>2</inf> support had VitD <30 ng/mL and <20 ng/mL than CPAP and NIMV patients. There were no relationships between VitD and the three classes of IgM (P=0.419) and of IgG (P=0.862) SARS-CoV-2 antibodies values. The behavior was the same for CRP.

CONCLUSIONS

Our study shows that a significant proportion of COVID-19 patients have a VitD deficiency and that this condition is more frequent in CPAP and in NIMV patients.

The pathophysiology and management of vascular calcification in chronic kidney disease patients

INTRODUCTION

Vascular calcification (VC) which is the pathological mineral deposition in the vascular system, predominantly at the intimal and medial layer of the vessel wall, is an important comorbidity in patients with chronic kidney disease (CKD) leading to significant morbidity and mortality while necessitating appropriate treatment. Our review aims to provide an in-depth analysis of the current understanding of VC.

AREAS COVERED

In this review, we first discuss the pathophysiology of VC in CKD patients, then we explain the methods to predict and assess VC. Afterwards, we provide the currently available as well as the potential therapeutic approaches of VC. We finally discuss our understanding regarding the current situation surrounding VC in our expert opinion section.

EXPERT OPINION

Predicting, assessing and treating VC is crucial and the future advances in the field of research surrounding VC will potentially occur in one or more of these three areas of clinical management. There is a current lack of evidence and consensus regarding specific therapeutic options for alleviating VC and this situation may not necessitate VC to be determined, detected, and documented before the available options are implemented. Regardless, the prediction and assessment of VC is still important and requires further improvement together with the developments in therapeutic alternatives. The future has the potential to bring better research which would guide and improve the management of this patient group. A more specialized approach consisting of targeted therapies and more tailored management plans for patients with CKD and VC is on the horizon.

The Role of Uremic Retention Solutes in the MIA Syndrome in Hemodialysis Subjects

INTRODUCTION

In chronic kidney disease (CKD), the high morbidity and mortality risk for cardiovascular disease (CVD) are not easily explained only on the basis of traditional factors. Among nontraditional ones involved in CKD, malnutrition, inflammation, and atherosclerosis/calcification have been described as the "MIA syndrome."

METHODS

In this pilot study, we evaluated the association between the variation in serum levels of 27 uremic retention solutes plus 6 indexes related to the MIA syndrome processes in a population of dialysis patients.

RESULTS

As expected, we found a direct correlation between serum albumin and both phosphate and total cholesterol (r = 0.54 and 0.37, respectively; p < 0.05). Moreover, total cholesterol and phosphate directly correlate (r = 0.40, p < 0.05). The relationship between malnutrition and inflammation is highlighted by the correlation of serum cholesterol levels with serum alpha-1 acid glycoprotein and IL-6 levels (r = -0.56, r = -0.39, respectively; p < 0.05). Moreover, the relation between inflammation and atherosclerosis/calcification is supported by the correlation of IL-6 with VEGF levels and vascular smooth muscle cell high-Pi in vitro calcification (r = 0.81, r = 0.66, respectively; p < 0.01).

CONCLUSION

We found significant correlations between several uremic retention solutes and malnutrition, inflammation, and atherosclerosis/calcification. Our findings support the hypothesis of a central role of the uremic milieu in the MIA syndrome and ultimately in the pathogenesis of CKD-specific CVD risk factors.

The new, race-free, Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation to estimate glomerular filtration rate: is it applicable in Europe? A position statement by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

The EFLM recommends not to implement the race-free Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation in European laboratories and to keep the 2009 version of the CKD-EPI equation, without applying a race correction factor. This recommendation is completely in line with a recent Editorial published by the European Renal Association who has also proposed to change to a novel equation only when it has considerably better performance, trying to reach global consensus before implementing such a new glomerular filtration rate (GFR) estimation equation. In Europe, this equation could be for instance the new European Kidney Function Consortium (EKFC) equation, which is population-specific, developed from European cohorts and accurate from infants to the older old. Beyond serum creatinine, the estimating equations based on cystatin C will probably gain in popularity, especially because cystatin C seems independent of race. Finally, we must keep in mind that all GFR equations remain an estimation of GFR, especially rough at the individual level. Measuring GFR with a reference method, such as iohexol clearance, remains indicated in specific patients and/or specific situations, and here also, the role of the clinical laboratories is central and should still evolve positively in the future.

Predictors of hypogammaglobulinemia in ANCA-associated vasculitis after a rituximab-based induction: a multicentre study

OBJECTIVES

Rituximab has become the cornerstone of induction treatment in ANCA-associated vasculitis (AAV). B cell depletion may increase the risk of hypogammaglobulinemia, potentially leading to severe infections. This study aims to assess factors associated with hypogammaglobulinemia in AAV patients treated with rituximab.

METHODS

This retrospective cohort study included AAV patients treated with rituximab induction in 14 European centers. Severe adverse events (SAEs) were defined as episodes requiring hospitalization or intravenous antibiotics, malignancies, or death. Linear and logistic regression were used to identify predictors of IgG levels and of the risk of hypogammaglobulinemia, defined as IgG ≤7 g/l at 6 months.

RESULTS

The study included 227 patients. IgG levels at 6 months were lower than baseline (p< 0.001). Patients requiring intravenous antibiotics during the first 6 months had lower IgG levels at 6 months (p= 0.004). Age (β [95%CI]: -0.23 [-0.38;-0.08] per 10 years, p= 0.003), oral glucocorticoid dose at induction (β [95%CI]:-0.37[-0.51;-0.24] per sqrt-transformed mg prednisone, p< 0.001) and concomitant use of intravenous glucocorticoid pulses (β [95%CI]:-0.88[-1.73;-0.02], p= 0.044) were associated with IgG levels at 6 months. Hypogammaglobulinemia was identified in 97 (42.7%) patients. In multivariable logistic regression, factors associated with the risk of hypogammaglobulinemia were age (OR [95%CI]: 1.46 [1.15; 1.86] per 10 years, p= 0.002) and oral glucocorticoid dose at induction (OR [95%CI]: 1.52[1.23; 1.89] per 10 mg prednisone, p< 0.001).

CONCLUSIONS

In AAV patients treated with rituximab, hypogammaglobulinemia at 6 months after induction is common, and lower IgG levels are associated with serious infections. The risk of hypogammaglobulinemia in these patients increases with age and higher glucocorticoid doses.

Management of fracture risk in CKD-traditional and novel approaches

The coexistence of osteoporosis and chronic kidney disease (CKD) is an evolving healthcare challenge in the face of increasingly aging populations. Globally, accelerating fracture incidence causes disability, impaired quality of life and increased mortality. Consequently, several novel diagnostic and therapeutic tools have been introduced for treatment and prevention of fragility fractures. Despite an especially high fracture risk in CKD, these patients are commonly excluded from interventional trials and clinical guidelines. While management of fracture risk in CKD has been discussed in recent opinion-based reviews and consensus papers in the nephrology literature, many patients with CKD stages 3-5D and osteoporosis are still underdiagnosed and untreated. The current review addresses this potential treatment nihilism by discussing established and novel approaches to diagnosis and prevention of fracture risk in patients with CKD stages 3-5D. Skeletal disorders are common in CKD. A wide variety of underlying pathophysiological processes have been identified, including premature aging, chronic wasting, and disturbances in vitamin D and mineral metabolism, which may impact bone fragility beyond established osteoporosis. We discuss current and emerging concepts of CKD-mineral and bone disorders (CKD-MBD) and integrate management of osteoporosis in CKD with current recommendations for management of CKD-MBD. While many diagnostic and therapeutic approaches to osteoporosis can be applied to patients with CKD, some limitations and caveats need to be considered. Consequently, clinical trials are needed that specifically study fracture prevention strategies in patients with CKD stages 3-5D.

Chronic kidney disease as cardiovascular risk factor in routine clinical practice: a position statement by the Council of the European Renal Association

The European Society of Cardiology 2021 guideline on cardiovascular (CV) disease (CVD) prevention in clinical practice has major implications for both CV risk screening and kidney health of interest to primary care physicians, cardiologists, nephrol-ogists, and other professionals involved in CVD prevention. The proposed CVD prevention strategies require as first step the categorization of individuals into those with established atherosclerotic CVD, diabetes, familiar hypercholesterolaemia, or chronic kidney disease (CKD), i.e. conditions that are already associated with a moderate to very-high CVD risk. This places CKD, defined as decreased kidney function or increased albuminuria as a starting step for CVD risk assessment. Thus, for adequate CVD risk assessment, patients with diabetes, familiar hypercholesterolaemia, or CKD should be identified by an initial laboratory assessment that requires not only serum to assess glucose, cholesterol, and creatinine to estimate the glomerular filtration rate, but also urine to assess albuminuria. The addition of albuminuria as an entry-level step in CVD risk assessment should change clinical practice as it differs from the current healthcare situation in which albuminuria is only assessed in persons already considered to be at high risk of CVD. A diagnosis of moderate of severe CKD requires a specific set of interventions to prevent CVD. Further research should address the optimal method for CV risk assessment that includes CKD assessment in the general population, i.e. whether this should remain opportunistic screening or whether systematic screening.

Cytokine and Chemokine Retention Profile in COVID-19 Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) patients are more susceptible to infections compared to the general population. SARS-CoV-2 virus pathology is characterized by a cytokine storm responsible for the systemic inflammation typical of the COVID-19 disease. Since CKD patients have a reduced renal clearance, we decided to investigate whether they accumulate harmful mediators during the COVID-19 disease. We conducted a retrospective study on 77 COVID-19 hospitalized subjects in the acute phase of the illness. Thirteen different cytokines were assessed in plasma collected upon hospitalization. The patients were divided into three groups according to their estimated glomerular filtration rate, eGFR < 30 (n = 23), 30 < eGFR < 60 (n = 33), eGFR > 60 mL/min (n = 21). We found that Tumor Necrosis Factor α and its receptors I and II, Interleukin-7, Leukemia Inhibitory Factor, FAS receptor, Chitinase 3-like I, and the Vascular Endothelial Growth Factor showed an increased accumulation that negatively correlate with eGFR. Moreover, non-survivor patients with an impaired kidney function have significantly more elevated levels of the same mediators. In conclusion, there is a tendency in COVID-19 ESRD patients to accumulate harmful cytokines. The accumulation seems to associate with mortality outcomes and may be due to reduced clearance but also to increased biosynthesis in most severe cases.

The “FIFTY SHADOWS” of the RALES Trial: Lessons about the Potential Risk of Dietary Potassium Supplementation in Patients with Chronic Kidney Disease

Hyperkalaemia (HK) is one of the most common electrolyte disorders and a frequent reason for nephrological consultations. High serum potassium (K⁺) levels are associated with elevated morbidity and mortality, mainly due to life-threatening arrhythmias. In the majority of cases, HK is associated with chronic kidney disease (CKD), or with the use of renin–angiotensin–aldosterone system inhibitors (RAASis) and/or mineral corticoid antagonists (MRAs). These drugs represent the mainstays of treatment in CKD, HF, diabetes, hypertension, and even glomerular diseases, in consideration of their beneficial effect on hard outcomes related to cardiovascular events and CKD progression. However, experiences in relation to the Randomised Aldactone Evaluation Study (RALES) cast a long shadow that extends to the present day, since the increased risk for HK remains a major concern. In this article, we summarise the physiology of K⁺ homeostasis, and we review the effects of dietary K⁺ on blood pressure and cardiovascular risk in the general population and in patients with early CKD, who are often not aware of this disease. We conclude with a note of caution regarding the recent publication of the SSaSS trial and the use of salt substitutes, particularly in patients with a limited capacity to increase K⁺ secretion in response to an exogenous load, particularly in the context of “occult” CKD, HF, and in patients taking RAASis and/or MRAs.

P-694 Dosage of exogenous gonadotropins is not related to blastocyst aneuploidy or cumulative live-birth rates in PGT-A cycles

Study question

Does dosage of gonadotropins affect aneuploidy rate rates or cumulative live birth rates (CLBRs) after the transfer of euploid embryos?

Summary answer

We did not find evidence that dosage gonadotropin influenced significantly the rate of aneuploidy and CLBRs after transfer of euploid embryos.

What is known already

Aneuploidy rates increase steadily with age, reaching &gt;80% in women &gt;42 years old. The goal of controlled ovarian stimulation obtaining more embryos to biopsy through the recruitment of several follicles, reaching more euploid embryos. However, several studies have suggested that a high response to stimulation might be embryotoxic and/or increase aneuploidy rates by enhancing the abnormal segregation of chromosomes during meiosis. Furthermore, a study on young donors showed differences in the euploidy rates, suggesting an iatrogenic etiology resulting from different stimulation methods.

Study design, size, duration

A multicenter retrospective study, with the preimplantation genetic test for aneuploidy (PGT-A) between January 2013 and January 2020 collected from clinics IVIRMA in Europe. 6832 cycles of in vitro fertilization (IVF) with PGT-A were included in the study

Participants/materials, setting, methods

A total of 62131 embryos were analyzed for ploidy status. Embryos that were subjected to chromosomal analysis were performed blastomere by aCGH (array Comparative Genomic Hybridization) or NGS (Next-Generation Sequencing) analysis. The embryos were biopsied on days 5 and 6. Women were divided into two age groups (&lt;37 and ≥37 years old). Outcomes were compared between different total gonadotropin dosages (&lt;3000 and ≥3000 IU), the dosage of hMG, and numbers of oocytes retrieved.

Main results and the role of chance

The total number of aneuploid embryos was 28336 of the 62131 embryos genetically screened using PGT-A. The embryonic aneuploidy rate was 59.4% (95%CI 58.5-60.3). In the group of women with gonadotropins dosage &lt;3000 IU the embryonic aneuploidy rate was 59.7% (95%CI 58.7-60.8) and in the group with gonadotropins dosage ≥3000 IU was 58.7% (95%CI 57.1-60.3) with no significant difference between them (P = 0.279). In the group of younger patients (&lt;37 y.o) the aneuploidy rate demonstrated no significant differences between patients who received low gonadotropin dosages and patients with high gonadotropin dosages (P = 0.06). Aneuploidy rates in the group of older patients (≥37 y.o) were similar regardless of gonadotropin dosing (P = 0.21). Dividing the according to the number of oocytes retrieved (10, 11-15, &gt;15), the analysis of aneuploidy rate revealed no association between the gonadotropin dosages administrated depending on the total number of retrieved oocytes and age. The aneuploidy rate was also analyzed considering the administration of hMG, there was no statistical difference in the aneuploidy rate with low or high hMG dosages also when it was stratified by age. The cumulative live-birth rate in the groups of different gonadotropins dosage and different ages of patients was similar across the group.

Limitations, reasons for caution

The retrospective nature is the major limitation of this study, also patients included in the study received PGT-A using NGS and CGH arrays technology. The aCGH analysis used is less sensitive than more recent NGS technology.

Wider implications of the findings

Our study demonstrated that gonadotropin dosage did not affect aneuploidy rate or cumulative live-birth rates suggesting that the high doses of gonadotropins used in ART cycles may be safe.

Trial registration number

not applicable

[Left atrial appendage occlusion as replacement of coumarin anticoagulants in calciphylaxis]

Calcific uremic arteriolopathy (CUA), often referred to as calciphylaxis, is a rare condition potentially life-threatening seen in 1-4% of patients with kidney failure on chronic dialysis. Pathogenesis is not clear, but several risk factors have been identified, one of the most known among them is coumarin anticoagulants therapy (tAC). When CUA occurs, tAC is contraindicated: the left atrial appendage occlusion, in dialysed patients affected by non-valvular atrial fibrillation, could be contemplated in replacement of tAC, that should be considered by nephrologist and discussed by a multidisciplinary team including cardiologists.

Can SGLT2 inhibitors answer unmet therapeutic needs in chronic kidney disease?

Chronic kidney disease (CKD) is a global health problem, affecting more than 850 million people worldwide. The number of patients receiving renal replacement therapy (dialysis or renal transplantation) has increased over the years, and it has been estimated that the number of people receiving renal replacement therapy will more than double from 2.618 million in 2010 to 5.439 million in 2030, with wide differences among countries. The main focus of CKD treatment has now become preserving renal function rather than replacing it. This is possible, at least to some extent, through the optimal use of multifactorial therapy aimed at preventing end-stage kidney disease and cardiovascular events. Sodium/glucose cotransporter 2 inhibitors (SGLT2i) reduce glomerular hypertension and albuminuria with beneficial effects on progression of renal damage in both diabetic and non-diabetic CKD. SGLT2 inhibitors also show great benefits in cardiovascular protection, irrespective of diabetes. Therefore, the use of these drugs will likely be extended to the whole CKD population as a new standard of care.

FC 101: The Impact of Vascular Access Types on Survival in Hemodialysis: Time for a Shift in Paradigm? A Prospective Cohort Study

BACKGROUND AND AIMS

Despite arteriovenous native fistula (AVF) is the vascular access (VA) of choice due to a better outcome than central venous catheter (CVC) [1], catheter use is still common among haemodialysis (HD) patients. Our study aims to describe the survival and epidemiological features of a cohort of dialysis patients with a focus on the role of VA type.

METHOD

Our cohort comprises a prospective follow-up conduced from 2001 to 2020, which led to recruit 754 patients in HD. We identified a subgroup of patients survived less than 7 months (n 124) and a subgroup of patients survived more or equal than 7 months and up to 60 months (n = 472). In addition to this, every subgroup was subdivided into two different age groups, including patients of age ≤74 years old and those ≥75 years old. Other analysed characteristics were demographic features and baseline clinical data, like primary cause of ESKD, co-morbidities at the beginning of the HD treatment and type of VA both at start of HD and at the end of the follow-up. Starting HD without planning, namely being ‘late referral’, was also considered. Descriptive analysis was performed on baseline data. Moreover, we analysed predictive variables of death for any cause with Univariate and Multivariate Logistic Regression. Predictors of survival were analysed through univariate and multivariate Cox regression.

RESULTS

At the multivariate logistic regression, the use of tunnelled CVC at the start of HD resulted protective against death from any cause (aOR, 0.43; P = 0.017) in the whole cohort (n = 754). In the subgroup analysis of patients (n = 124) with a follow-up &lt; 7 months, malignancy (aOR, 4.57; P = 0.002), severe cardiomyopathy (aOR, 4.35; P = 0.001) and vascular disease (aOR, 3.22; P = 0.008) were estimated as significantly predictors of death. At the multivariate Cox analysis, being ‘late referral’ was associated with decreased survival within 6 months (aHR, 3.79; P = 0.001). In the subgroup of elderly (≥75 years old; n = 201/472) survived within 7–60 months, multivariate logistic regression showed that the use of tunnelled CVC at the start of HD (Figure 1) resulted even more protective against death (aOR 0.25; P = 0.021). Moreover, vascular disease resulted as the main risk factor for death (aOR 5.11; P = 0.000), and it was confirmed as the only independent risk factor at the COX analysis (aHR 1.58; P = 0.017; see Figure 2).

CONCLUSION

Vascular disease is the main risk factor for death in haemodialysis patients. Furthermore, cardiovascular disease influences patient outcome more than the VA type, confirming the assumption that the choice of VA might be influenced by several issues as age and comorbidities [2, 3]. In the short-term survival subgroup, neither VA nor age emerged to be predictor of mortality, suggesting that health status before starting maintenance HD might explain an important part of the risk often attributed to catheter use.[4] Moreover, starting RRT without proper planning (‘late referral’) was extremely relevant in determining short-term survival. Tunnelled CVC might be the option of choice as VA, specifically in the elderly with vascular disease. In conclusion, our long-term experience suggests that the choice of VA should not necessarily follow the ‘fistula first’ approach, but it should be based on dialytic life expectancy and comorbidities.

The Role of Rituximab in Primary Focal Segmental Glomerular Sclerosis of the Adult

Introduction

Primary focal segmental glomerular sclerosis (FSGS) is a rare, likely immune-mediated disease. Rituximab (RTX) may play a role in management, although data in adults are scanty.

Methods

We collected cases of RTX-treated primary FSGS within the Italian Society of Nephrology Immunopathology Working Group and explored response rate (24-hour proteinuria <3.5 g and <50% compared with baseline, stable estimated glomerular filtration rate).

Results

A total of 31 patients were followed for at least 12 months; further follow-up (median 17 months, interquartile range [IQR] 15–33.5) was available for 11. At first RTX administration, median creatinine and 24-hour proteinuria were 1.17 mg/dl (IQR 0.83–1.62) and 5.2 g (IQR 3.3–8.81), respectively. Response rate at 3, 6, and 12 months was 39%, 52%, and 42%, respectively. In the first 12 months, creatinine level remained stable whereas proteinuria and serum albumin level improved, with an increase in the proportion of patients tapering other immunosuppressants. There were 6 patients who were retreated with RTX within 12 months, either for proteinuria increase or refractory disease; only the 2 responders to the first RTX course experienced a further response. At univariate analysis, 6-month response was more frequent in steroid-dependent patients (odds ratio [OR] 7.7 [95% CI 1.16–52.17]) and those with proteinuria <5 g/24 h (OR 8.25 [1.45–46.86]). During long-term follow-up, 4 of 5 responders at 12 months maintained a sustained response, either without further immunosuppression (2 of 4) or with pre-emptive RTX (2 of 4); 1 relapsed and responded to RTX retreatment.

Conclusion

RTX may be an option in primary FSGS, especially in steroid-dependent patients, with 24-hour proteinuria <5 g and previously responders to RTX. Optimal long-term management for responders is unclear, with some patients experiencing sustained remission and others requiring RTX retreatment, either preemptive or after rising proteinuria.

Facial approximation for identification purposes: soft tissue thickness in a Caucasian population. Sex and age-related variations

The aim of this study was to collect soft tissue thickness (STT) values of an Italian population from 12 bone landmarks, to improve the facial approximation process for identification purposes. 100 Italian adults (50 males and 50 females), who had undergone head CT for clinical purposes, were analysed in order to expand the database of the Italian population. Average values, standard deviation and range were collected according to gender and age and the obtained values were statistically analysed in order to evaluate any possible significant difference. Only one landmark was statistically significant associated with sex, females showed significantly higher values for para-zygomaxillary. Two landmarks were statistically significant associated with age, upper incisor and pogonion. The obtained results were compared with the existing literature. Such information can be useful in the forensic craniofacial reconstruction process and can facilitate choosing the most suitable STT values according to osteological analysis of the human remains.

Time for Revival of Bone Biopsy with Histomorphometric Analysis in Chronic Kidney Disease (CKD): Moving from Skepticism to Pragmatism

Bone Biopsy (BB) with histomorphometric analysis still represents the gold standard for the diagnosis and classification of different forms of renal osteodystrophy. Bone biopsy is the only technique able to provide comprehensive information on all bone parameters, measuring static and dynamic parameters of turnover, cortical and trabecular microarchitecture, and mineralization defects. In nephrological practice, bone biopsy yields relevant indications to support therapeutic choices in CKD, heavily impacting the management and prognosis of uremic patients. Unfortunately, the use of bone biopsy has decreased; a lack of expertise in performing and interpreting, perceived procedure invasiveness and pain, and reimbursement issues have all contributed to this decline. Nevertheless, both bone biomarkers and instrumental images cannot be considered reliable surrogates for histological findings, being insufficiently accurate to properly evaluate underlying mineral and bone disorders. This is a multidisciplinary position paper from the Nephrology and Osteoporosis Italian Scientific Societies with the purpose of restating the role of bone biopsy in CKD patient management and of providing strong solutions to allow diffusion of this technique in Italy, but potentially also in other countries. The Italian approach through the optimization and standardization of bone biopsy procedure, the construction of the Italian Hub and Spoke network, and a request for adjustment and national homogenization of reimbursement to the Italian Health Ministry has led the way to implement bone biopsy and to improve CKD patient management and prognosis.

OUP accepted manuscript

Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

Calciphylaxis after Kidney Transplantation: a rare but life-threatening disorder

Calciphylaxis is a rare disorder characterized by vascular calcification and thrombosis of the subcutaneous microcirculation, leading to painful necrotic skin lesions and bearing a dreadfully high mortality rate. This syndrome is frequently also termed uraemic calcific arteriolopathy, since most cases are observed in patients with kidney failure. However, it is increasingly clear that calciphylaxis may also affect patients with normal or only slightly impaired renal function, including kidney transplant recipients. A precise definition of the characteristics and risk factors of calciphylaxis developing after kidney transplantation has been hindered by the extreme rarity of this condition, which also hampered the development of effective therapeutic strategies. In the present issue of CKJ, Guillén and colleagues report the largest case series of calciphylaxis in kidney transplant recipients to date, outlining several features that are apparently specific to this population. In this editorial, we briefly present the epidemiology and pathogenesis of calciphylaxis in different patient populations and discuss recent findings for its therapeutic management.