Balanced crystalloid solution versus saline in deceased donor kidney transplantation (BEST-Fluids): a pragmatic, double-blind, randomised, controlled trial.

BACKGROUND: Delayed graft function (DGF) is a major adverse complication of deceased donor kidney transplantation. Intravenous fluids are routinely given to patients receiving a transplant to maintain intravascular volume and optimise graft function. Saline (0·9% sodium chloride) is widely used but might increase the risk of DGF due to its high chloride content. We aimed to test our hypothesis that using a balanced low-chloride crystalloid solution (Plasma-Lyte 148) instead of saline would reduce the incidence of DGF. METHODS: BEST-Fluids was a pragmatic, registry-embedded, multicentre, double-blind, randomised, controlled trial at 16 hospitals in Australia and New Zealand. Adults and children of any age receiving a deceased donor kidney transplant were eligible; those receiving a multi-organ transplant or weighing less than 20 kg were excluded. Participants were randomly assigned (1:1) using an adaptive minimisation algorithm to intravenous balanced crystalloid solution (Plasma-Lyte 148) or saline during surgery and up until 48 h after transplantation. Trial fluids were supplied in identical bags and clinicians determined the fluid volume, rate, and time of discontinuation. The primary outcome was DGF, defined as receiving dialysis within 7 days after transplantation. All participants who consented and received a transplant were included in the intention-to-treat analysis of the primary outcome. Safety was analysed in all randomly assigned eligible participants who commenced surgery and received trial fluids, whether or not they received a transplant. This study is registered with Australian New Zealand Clinical Trials Registry, (ACTRN12617000358347), and ClinicalTrials.gov (NCT03829488). FINDINGS: Between Jan 26, 2018, and Aug 10, 2020, 808 participants were randomly assigned to balanced crystalloid (n=404) or saline (n=404) and received a transplant (512 [63%] were male and 296 [37%] were female). One participant in the saline group withdrew before 7 days and was excluded, leaving 404 participants in the balanced crystalloid group and 403 in the saline group that were included in the primary analysis. DGF occurred in 121 (30%) of 404 participants in the balanced crystalloid group versus 160 (40%) of 403 in the saline group (adjusted relative risk 0·74 [95% CI 0·66 to 0·84; p<0·0001]; adjusted risk difference 10·1% [95% CI 3·5 to 16·6]). In the safety analysis, numbers of investigator-reported serious adverse events were similar in both groups, being reported in three (<1%) of 406 participants in the balanced crystalloid group versus five (1%) of 409 participants in the saline group (adjusted risk difference -0·5%, 95% CI -1·8 to 0·9; p=0·48). INTERPRETATION: Among patients receiving a deceased donor kidney transplant, intravenous fluid therapy with balanced crystalloid solution reduced the incidence of DGF compared with saline. Balanced crystalloid solution should be the standard-of-care intravenous fluid used in deceased donor kidney transplantation. FUNDING: Medical Research Future Fund and National Health and Medical Research Council (Australia), Health Research Council (New Zealand), Royal Australasian College of Physicians, and Baxter.

Cardiac Output Changes during Renal Replacement Therapy: A Scoping Review.

INTRODUCTION: Renal replacement therapy (RRT) is associated with hypotension. However, its impact on cardiac output (CO) is less understood. We aimed to describe current knowledge of CO monitoring and changes during RRT. METHODS: We searched MEDLINE, Embase, and Cochrane from January 1, 2000, to January 31, 2023, using Covidence for studies of intermittent hemodialysis (IHD) and continuous RRT (CRRT) with at least three CO measurements during treatment. Two independent reviewers screened citations, and a third resolved disagreements. The findings did not allow meta-analysis and are presented descriptively. RESULTS: We screened 3,285 articles and included 48 (37 during IHD, nine during CRRT, and two during both). Non-invasive devices (electrical conductivity techniques and finger cuff pulse contour) were the most common CO measurement techniques (21 studies). The median baseline cardiac index in IHD studies was 3 L/min/m2 (95% CI, 2.7-3.39). Among the 88 patient cohorts studied, a decrease in CO occurred in 63 (72%). In 16 cohorts, the decrease was severe (>25%). Changes in blood pressure (BP) were not concordant in extent or direction with changes in CO. The decrease in CO correlated weakly with ultrafiltration rate (r = -0.3, p = 0.05) and strongly with changes in systemic vascular resistance (SVR) (r = -0.6, p < 0.001). CONCLUSION: There are limited data on CO changes during RRT. However, a decrease in CO appeared common and was marked in 1 of 5 patient cohorts. Such decreases often occurred without BP changes and were associated with increased SVR.

Tunnelled central venous catheters for incident haemodialysis patients: a Victorian survey exploring reasons for use.

BACKGROUND: Tunnelled central venous catheters (T-CVCs) are used globally as vascular access for patients on haemodialysis (HD) but are associated with increased sepsis, mortality, cost and length of hospitalisation compared with more permanent HD vascular access. The reasons for using T-CVC are varied and poorly understood. A significant and increasing proportion of incident HD patients in Victoria, Australia, have required T-CVC over the last decade. AIM: To explore reasons for a significant and increasing proportion of incident HD patients in Victoria, Australia, having required T-CVC over the last decade. METHODS: With rates of starting HD with definitive vascular access consistently below a Victorian quality indicator target of 70%, an online survey was developed to explore reasons why the rate remained lower than desired and to help inform future decisions about this quality indicator. The survey was completed by dialysis access coordinators over an 8-month period and involved all public nephrology services in Victoria. RESULTS: Of the 125 surveys completed, 101 incident HD patients had no attempt at permanent vascular access prior to T-CVC insertion. For almost half of these (48 patients), there was no active medical decision not to create permanent vascular access prior to commencing dialysis. Reasons for insertion of the T-CVC included deterioration of kidney function faster than anticipated, surgical referral being overlooked, complications related to peritoneal dialysis requiring a change in dialysis modality and changes to initial decisions regarding dialysis modality for kidney failure. CONCLUSIONS: These survey results provide an opportunity for quality improvement initiatives with respect to dialysis access planning and care.

Lower versus higher starting tacrolimus dosing in kidney transplant recipients.

Achieving therapeutic tacrolimus levels is an essential component of balancing immunosuppression in kidney transplantation. At our institution, the starting tacrolimus dose was reduced from .075 mg/kg BD (higher dose [HD]) to .050 mg/kg BD (lower dose [LD]), to better achieve our target level of 6-10 µg/L in the early posttransplant period. Kidney transplant recipients (KTRs) transplanted 1-year before (HD: n = 64) and after (LD: n = 63) the starting dose reduction were retrospectively compared. Achieved tacrolimus levels were significantly lower in the LD group during the first 14 days posttransplant, but not at day 21 or day 28. A higher proportion of LD KTRs achieved therapeutic levels (day 1-3: 36.1% vs. 18.8%; day 4-7: 50.8% vs. 40.6%, day 8-14: 83.6% vs. 71.7%), while the HD KTRs were more likely to have supratherapeutic levels. Tacrolimus dose was significantly lower on day 5 compared to day 0 in the HD group but similar in the LD group. Rates of delayed graft function, posttransplant diabetes, and treated rejection at 6 months and graft outcomes at 3 years were all similar. Lowering the starting tacrolimus dose increased the proportion of KTRs achieving therapeutic range and minimized dose changes early posttransplant without an impact on clinical outcomes.

COVID-19 beliefs and vaccination uptake in dialysis patients: lessons from an anonymous patient survey.

BACKGROUND: There is a lack of data on how to best optimise uptake of COVID-19 vaccination in dialysis patients. AIM: To understand attitudes and beliefs about COVID-19 and vaccination uptake in dialysis patients. METHODS: A single-centre, cross-sectional study involving a clinical audit and an anonymous survey of adult maintenance dialysis patients was conducted. RESULTS: The vaccination uptake during the study period was 77.5% at least single dose, compared with 70% in Victoria during the same period. Participants were more likely to be vaccinated if they believed COVID-19 was a serious problem that is worse for people on dialysis. Those unvaccinated were more likely to overestimate the risk of vaccine complications and less likely to have the annual influenza vaccine. Despite over 80% of participants agreeing that they would have the vaccine if recommended by their nephrologist, less than 40% reported receiving information from this source. A predominant reason for vaccine hesitancy was concern regarding vaccine safety. Over 60% of those who were unvaccinated were still open to the vaccine, indicating a significant opportunity to improve vaccination rates through medical consultation and direction. CONCLUSIONS: Vaccine hesitancy for COVID-19 in dialysis patients associates with less informed health beliefs, both about the disease and the risks of vaccination. Patients are more likely to get vaccinated if it is recommended by their nephrologist. Clinicians caring for dialysis patients have a key role in providing high-quality education and advice, representing an urgent opportunity for improvement in vaccination uptake against COVID-19.

Relationship between residual kidney function and symptom burden in haemodialysis patients.

BACKGROUND: Residual kidney function (RKF) has been associated with improved solute clearance and survival in haemodialysis (HD) patients. However, whether RKF impacts symptom burden in HD patients is unknown. AIMS: To determine the prevalence of RKF in HD patients and to explore associations between higher levels of RKF with symptom burden, as well as clinical and biochemical parameters. METHODS: This is a single-centre, retrospective, observational study. RKF was assessed as urea clearance (KRU) by interdialytic urine collection. Symptom burden was measured using the palliative care outcome scale renal questionnaire. RESULTS: A total of 90 maintenance HD patients was recruited; 31.9% had KRU ≥1 mL/min/1.73 m2 . Patients with KRU ≥1 mL/min/1.73 m2 reported fewer symptoms (5.3 ± 3.5 vs 7.7 ± 3.8) (P = 0.011), including less shortness of breath (15% vs 55%) (P = 0.0013) and vomiting (0% vs 30%) (P = 0.0016). Higher RKF was associated with lower ß2 -microglobilin (P < 0.0001), and lower serum potassium (P = 0.02), but no difference in phosphate, haemoglobin, C-reactive protein or serum albumin. CONCLUSION: Higher RKF was significantly associated with fewer symptoms, and lower serum ß2 -microglobulin and potassium, suggesting that strategies to preserve RKF may be beneficial.

Dialysis and driving: an anonymous survey of patients receiving dialysis for end-stage kidney disease.

BACKGROUND: Driving is a complex task requiring multiple cognitive domains and the musculoskeletal system. Cognitive dysfunction is associated with driving impairment. Dialysis patients are known to have a high prevalence of cognitive impairment and other comorbidities, and may be at risk of driving impairment. No Australian guidelines address driving safety in dialysis patients. AIMS: To estimate the proportion of dialysis patients who were driving and those at risk of driving impairment, and to investigate the agreement between objective and subjective markers of risk. METHODS: This single-centre study involved dialysis patients voluntarily completing two questionnaires relating to risk of driving impairment; the first questionnaire focussed on objective markers, and the second questionnaire focussed on subjective markers. Risk of driving impairment was established using pre-determined criteria, and the agreement between objective and subjective markers was estimated using Cohen kappa. RESULTS: A total of 44.8% (99/221) of patients participated; 76.8% (76/99) of participants were driving, and 76.3% (58/76) of drivers were at risk of driving impairment. Factors associated with at-risk driving included post dialysis dizziness, leg weakness or numbness, falling asleep while driving and hypoglycaemia. Sixteen patients reported collisions since commencing dialysis. The questionnaires displayed slight agreement (Cohen kappa = 0.20) between objective and subjective markers. CONCLUSIONS: Dialysis patients are at risk of driving impairment based on self-reported questionnaire responses. Discrepancies between patients' perceptions and objective markers were apparent. Further research into appropriate risk assessments, as well as development of guidelines to aid in determining driving safety in dialysis patients, is needed.

A tRial Evaluating Mid Cut-Off Value Membrane Clearance of Albumin and Light Chains in HemoDialysis Patients: A Safety Device Study.

BACKGROUND: A new class of dialysis membrane, the mid cut-off (MCO) dialyzer, has been developed to improve the clearance of uremic toxins in hemodialysis (HD). The a tRial Evaluating Mid cut-Off Value membrane clearance of Albumin and Light chains in HemoDialysis patients (REMOVAL-HD) study aimed to determine if regular use of MCO dialyzer was safe and specifically did not result in a significant loss of albumin. METHODS: This investigator initiated, crossover, longitudinal, device study was conducted across 9 centers in Australia and New Zealand (n = 89). Participants had a 4-week wash-in with high-flux HD, followed by 24-week intervention with MCO HD and a subsequent 4-week wash-out with high-flux HD. The primary outcome was change in serum albumin between weeks 4 and 28. Secondary outcomes included trends in serum albumin, changes in kappa- and lambda-free light chains (FLC), 6-min walk test (6MWT), malnutrition inflammation score (MIS), restless legs score and quality of life. RESULTS: Participants had a mean age of 66 ± 14 years, 62% were men, 45% were anuric, and 51% had -diabetes. There was no reduction in serum albumin following treatment with MCO HD (mean reduction -0.7 g/L, 95% CI -1.5 to 0.1). A sustained, unexplained reduction in serum albumin (>25%) was not observed in any participant. A reduction in FLC was observed 2 weeks into MCO HD (lambda-FLC: Δ -9.1 mg/L, 95% CI -14.4 to -3.7; kappa-FLC: Δ -5.7 mg/L, 95% CI -9.8 to -1.6) and was sustained for the rest of the study intervention. Both FLC increased after the cessation of MCO use. There was no improvement in restless legs symptoms, quality of life, 6MWT or MIS scores. CONCLUSIONS: Regular HD using the MCO dialyzer did not result in a significant fall in serum albumin. There were no effects on quality of life, functional status or nutrition. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry Number (ANZCTRN) 12616000804482.

Baseline characteristics of patients with atypical haemolytic uraemic syndrome (aHUS): The Australian cohort in a global aHUS registry.

AIMS: To describe the baseline characteristics and treatment of Australian patients diagnosed with atypical haemolytic uraemic syndrome (aHUS) reported to the Global aHUS Registry. METHODS: Descriptive analysis of the Australian cohort with aHUS (n = 106) was undertaken for demographics, disease characteristics and prior treatment with eculizumab; comparing with the global cohort (n = 1688) for certain pre-specified disease characteristics. RESULTS: In Australia, almost two-thirds of patients diagnosed with aHUS were female and over 80% of patients were Caucasians, with similar proportions reported in the global cohort. Less than 6% of patients in the Australia and global cohorts were reported to have a history of autoimmune disease (4% vs 2%, respectively; P = .21) or cancer (5% vs 5%, respectively; P = .93), conditions that have been associated with secondary HUS. In the Australian cohort, 26% had received a kidney transplant and 68% of patients had received eculizumab. Kidneys were the most common organ involvement, followed by gastrointestinal tract (26%) and cardiovascular system (19%), with 35% of patients reported to have had at least two organs involved within 6 months prior to baseline visit or entry into the registry. Complement factor H was the most common pathogenic complement gene variant in the Australian patients. CONCLUSION: Data from the aHUS registry confirms and defines region-specific disease characteristics among a selected group of Australian children and adults with aHUS reported to the registry. Ongoing and more inclusive data will provide further information about temporal trends and treatment outcomes, representing a unique opportunity for clinicians and researchers to further develop knowledge surrounding this rare disease.

Absence of the ß1 subunit of AMP-activated protein kinase reduces myofibroblast infiltration of the kidneys in early diabetes.

Activation of the heterotrimeric energy-sensing kinase AMP-activated protein kinase (AMPK) has been reported to improve experimental diabetic kidney disease. We examined the effect of type 1 diabetes in wild-type (WT) mice and mice lacking the ß1 subunit of AMPK (AMPK ß1-/- mice), which have reduced AMPK activity in kidneys and other organs. Diabetes was induced using streptozotocin (STZ) and the animals followed up for 4 weeks. Hyperglycaemia was more severe in diabetic AMPK ß1-/- mice, despite the absence of any difference in serum levels of insulin, adiponectin and leptin. There was no change in AMPK activity in the kidneys of diabetic WT mice by AMPK activity assay, or phosphorylation of either the αT172 activation site on the α catalytic subunit of AMPK or the AMPK-specific phosphosite S79 on acetyl CoA carboxylase 1 (ACC1). Phosphorylation of the inhibitory αS485 site on the α subunit of AMPK was significantly increased in the WT diabetic mice compared to non-diabetic controls. Despite increased plasma glucose levels in the diabetic AMPK ß1-/- mice, there were fewer myofibroblasts in the kidneys compared to diabetic WT mice, as evidenced by reduced α-smooth muscle actin (α-SMA) protein by Western blot, mRNA by qRT-PCR and fewer α-SMA-positive cells by immunohistochemical staining. Albuminuria was also reduced in the AMPK ß1-/- mice. In contrast to previous studies, therefore, myofibroblasts were reduced in the kidneys of AMPK ß1-/- diabetic mice compared to diabetic WT mice, despite increased circulating glucose, suggesting that AMPK can worsen renal fibrosis in type 1 diabetes.

Risk factors for foot ulceration in adults with end-stage renal disease on dialysis: a prospective observational cohort study.

BACKGROUND: Dialysis patients experience high rates of foot ulceration. Although risk factors for ulceration have been extensively studied in patients with diabetes, there is limited high-quality, longitudinal evidence in the dialysis population. Therefore, this study investigated risk factors for foot ulceration in a stable dialysis cohort. METHODS: We prospectively collected clinical, demographic, health status, and foot examination information on 450 adults with end-stage renal disease from satellite and home-therapy dialysis units in Melbourne, Australia over 12 months. The primary outcome was foot ulceration. Cox proportional hazard modelling and multinomial regression were used to investigate risk factors. RESULTS: Among 450 dialysis patients (mean age, 67.5 years; 64.7% male; 94% hemodialysis; 50.2% diabetes), new cases of foot ulceration were identified in 81 (18%) participants. Overall, risk factors for foot ulceration were neuropathy (HR 3.02; 95% CI 1.48 to 6.15) and previous ulceration (HR 2.86; CI 1.53 to 5.34). In those without history of ulceration, nail pathology (RR 3.85; CI 1.08 to 13.75) and neuropathy (RR 2.66; CI 1.04 to 6.82) were risk factors. In those with history of ulceration, neuropathy (RR 11.23; CI 3.16 to 39.87), peripheral arterial disease (RR 7.15; CI 2.24 to 22.82) and cerebrovascular disease (RR 2.08; CI 1.04 to 4.16) were risk factors. There were 12 (2.7%) new amputations, 96 (21.3%) infections, 24 (5.3%) revascularizations, 42 (9.3%) foot-related hospitalizations, and 52 (11.6%) deaths. CONCLUSIONS: Neuropathy and previous ulceration are major risk factors for foot ulceration in dialysis patients. Risk factors differ between those with and without prior ulceration. The risk factors identified will help to reduce the incidence of ulceration and its associated complications.

Phosphorylation of Acetyl-CoA Carboxylase by AMPK Reduces Renal Fibrosis and Is Essential for the Anti-Fibrotic Effect of Metformin.

BACKGROUND: Expression of genes regulating fatty acid metabolism is reduced in tubular epithelial cells from kidneys with tubulointerstitial fibrosis (TIF), thus decreasing the energy produced by fatty acid oxidation (FAO). Acetyl-CoA carboxylase (ACC), a target for the energy-sensing AMP-activating protein kinase (AMPK), is the major controller of the rate of FAO within cells. Metformin has a well described antifibrotic effect, and increases phosphorylation of ACC by AMPK, thereby increasing FAO. METHODS: We evaluated phosphorylation of ACC in cell and mouse nephropathy models, as well as the effects of metformin administration in mice with and without mutations that reduce ACC phosphorylation. RESULTS: Reduced phosphorylation of ACC on the AMPK site Ser79 occurred in both tubular epithelial cells treated with folate to mimic cellular injury and in wild-type (WT) mice after induction of the folic acid nephropathy model. When this effect was exaggerated in mice with knock-in (KI) Ser to Ala mutations of the phosphorylation sites in ACC, lipid accumulation and fibrosis increased significantly compared with WT. The effect of ACC phosphorylation on fibrosis was confirmed in the unilateral ureteric obstruction model, which showed significantly increased lipid accumulation and fibrosis in the KI mice. Metformin use was associated with significantly reduced fibrosis and lipid accumulation in WT mice. In contrast, in the KI mice, the drug was associated with worsened fibrosis. CONCLUSIONS: These data indicate that reduced phosphorylation of ACC after renal injury contributes to the development of TIF, and that phosphorylation of ACC is required for metformin's antifibrotic action in the kidney.

The importance of residual kidney function in haemodialysis patients.

In contrast to peritoneal dialysis, residual kidney function (RKF) is commonly disregarded for haemodialysis (HD) patients and not regularly monitored or taken into account in routine clinical care. This is despite evidence that higher levels of RKF in HD patients are associated with better outcomes, including survival, total solute clearance, nutrition, inflammation and fluid balance. This review aims to summarise the clinical effects of RKF specifically in HD patients. Some level of RKF is present in over 80% of patients at the time of dialysis initiation, and while this declines over time, up to 30% of patients on HD for 5 years still have a measurable level of native kidney function. There is little evidence on how best to preserve RKF in HD patients, although it has been observed that intensive HD regimens in incident HD patients appear to accelerate RKF decline. RKF is not commonly factored into HD prescription and measures of adequacy, despite the fact that some guidelines such as Kidney Disease Outcomes Quality Initiative (KDOQI) and European Best Practice Guidelines suggest that it is reasonable to do so. This likely relates, at least in part, to perceived concerns regarding the inconvenience of timed urine collections and to the complexity and lack of consensus regarding the methods for integrating the intermittent clearance of HD with the continuous clearance of native renal function. Further research is required into how best to maintain and maximise the benefits of RKF in HD patients.

Pulmonary embolism with endovascular thrombolysis for thrombosed hemodialysis arteriovenous access
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AIMS: Acute thrombosis of hemodialysis (HD) arteriovenous access is an urgent problem for HD patients and is commonly managed by endovascular thrombolysis. Pulmonary embolism (PE) is a recognized complication of HD access thrombosis and thrombolysis but the risk and outcomes are unclear. This study aims to determine the incidence, predictors, and outcomes of PE after endovascular thrombolysis of HD arteriovenous access in patients presenting with acute thrombosis. MATERIALS AND METHODS: A single-center retrospective study was performed for all adult chronic kidney disease patients undergoing arteriovenous access thrombolysis between January 1, 2012, and December 31, 2014. Investigation for PE with CT pulmonary angiography or ventilation/perfusion scintigraphy (V/Q scan) was performed as clinically directed by the managing clinicians. In cases diagnosed with PE, the pulmonary embolism severity index (PESI) was calculated. RESULTS: A total of 48 (median age 68) patients underwent 74 thrombolysis procedures. Thrombolysis techniques were divided into pharmacological (44.6%), mechanical (17.6%), or pharmacomechanical (37.8%). Clinical success was achieved in 56/74 (75.7%) of procedures. Five episodes of thrombolysis for access thrombosis (6.8%) were associated with clinically symptomatic PE. The PESI score ranged from 51 to 127. All patients with PE were managed with 3 - 6 months of anticoagulation and recovered clinically. There were no statistically significant differences in baseline characteristics, methods of thrombolysis, or clot burden in patients that developed a PE. CONCLUSION: There is a clinically significant risk of symptomatic PE after arteriovenous access thrombolysis for access thrombosis in HD patients.
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Suspected atypical haemolytic uraemic syndrome in two post-partum patients with foetal-death in utero responding to eculizumab.

BACKGROUND: Atypical haemolytic uraemic syndrome (aHUS) is a rare condition with the triad of microangiopathic haemolytic anaemia, thrombocytopenia and acute kidney injury. Other conditions that present in a similar manner peri-partum include thrombotic thrombocytopaenic purpura, and pregnancy associated conditions including HELLP syndrome (haemolysis, elevated liver enzymes and low platelets), severe pre-eclampsia and less commonly acute fatty liver of pregnancy. CASE REPORTS: We describe two cases of suspected aHUS, who presented post-partum with foetal death-in-utero at 33 and 37 weeks respectively. Both presented with the triad features of aHUS but had considerably different clinical courses. The first case required a prolonged ICU admission, needed intubation for neurological deterioration and dialysis for acute kidney injury, and developed complications including acute liver failure, septic shock, pancreatitis, and ischaemic colitis. Initial ADAMSTS13 activity was borderline-low (10.3%) and normal on repeat testing (42.6%), and there was no peri-partum pre-eclampsia. The other case remained clinically stable throughout her admission with creatinine peaking at 495, not requiring dialysis, minor liver transaminases derangement and was discharged after a week. Her ADAMSTS13 activity was normal (62%), and her pregnancy was complicated by peri-partum pre-eclampsia. Both eventually had a reduction in haemolysis with rapid and sustained reduction in LDH and normalised platelet counts, and complete recovery of renal function whilst receiving eculizumab therapy. CONCLUSIONS: It can be difficult to distinguish aHUS from other causes in peri-partum patients presenting with features of microangiopathic haemolytic anaemia, thrombocytopenia and acute kidney injury, and often, aHUS can be precipitated by pregnancy. In the setting of the clinical urgency to treat aHUS early with eculizumab, this presents a diagnostic challenge, as confirmatory tests for aHUS are not immediately available.

Factors associated with foot ulceration and amputation in adults on dialysis: a cross-sectional observational study.

BACKGROUND: Adults on dialysis are at increased risk of foot ulceration, which commonly precedes more serious lower limb complications, including amputation. Limited data exist regarding the prevalence and factors associated with foot disease in this population. Hence, this study set out to investigate factors associated with foot ulceration and amputation in a dialysis cohort. METHODS: This study presents a cross-sectional analysis of baseline data from a multi-center prospective cohort study. We recruited 450 adults with end-stage renal disease on dialysis from multiple satellite and home-therapy dialysis units in Melbourne, Australia from January to December 2014. Data collection consisted of a participant interview, medical record review, health-status questionnaire and non-invasive foot examination. Logistic regression analyses were conducted to evaluate associations between screened variables and study outcomes. RESULTS: Mean age was 67.5 (SD, 13.2) years, 64.7% were male, 94% were on hemodialysis, median dialysis duration was 36.9 (IQR, 16.6 to 70.1) months, and 50.2% had diabetes. There was a high prevalence of previous ulceration (21.6%) and amputation (10.2%), 10% had current foot ulceration, and 50% had neuropathy and/or peripheral arterial disease. Factors associated with foot ulceration were previous amputation (OR, 10.19), peripheral arterial disease (OR, 6.16) and serum albumin (OR, 0.87); whereas previous and/or current ulceration (OR, 167.24 and 7.49, respectively) and foot deformity (OR, 15.28) were associated with amputation. CONCLUSIONS: Dialysis patients have a high burden of lower limb complications. There are markedly higher risks of foot ulceration and/or amputation in those with previous and/or current ulceration, previous amputation, peripheral arterial disease, lower serum albumin, and foot deformity. Although not a major risk factor, diabetes in men was an important effect modifier for risk of ulceration.

Balancing the energy equation for healthy kidneys.

The high-energy requirement of the kidney and the importance of energy metabolism in renal physiology has been appreciated for decades, but only recently has there emerged a strong link between impaired renal energy metabolism and chronic kidney disease (CKD). The mechanisms underlying the association between changes in energy metabolism and progression of CKD, however, remain poorly understood. A new study from Qiu and colleagues reported in the Journal of Pathology has advanced this understanding by showing that, after renal injury, the energy sensor AMPK inhibits epithelial-mesenchymal transition and inflammation, processes important in the pathogenesis of CKD. Furthermore, this study identifies an interaction between AMPK and CK2ß as an important mechanism in the anti-fibrotic effect. CK2ß has previously been shown to interact with STK11 (also known as LKB1) to regulate cellular polarity. These findings are consistent with the known roles of the LKB1-AMPK pathway in sustaining cellular energy homeostasis and epithelial cell polarity, and add to growing evidence linking the suppression of energy metabolism to CKD. They emphasize the importance of energy metabolism in general and the LKB1-AMPK axis in particular as key investigational and therapeutic targets in the battle against CKD.

Normal saline versus lower-chloride solutions for kidney transplantation.

BACKGROUND: The ideal intravenous fluid for kidney transplantation has not been defined, despite the common use of normal saline during the peri-operative period. The high chloride content of normal saline is associated with an increased risk of hyperchloraemic metabolic acidosis, which may in turn increase the risk of hyperkalaemia and delayed graft function. Balanced electrolyte solutions have a lower chloride content which may decrease this risk and avoid the need for dialysis due to hyperkalaemia in the immediate post-transplant period. Randomised controlled trials (RCTs) addressing this issue have used biochemical outcomes to compare fluids and have been underpowered to address patient-centred outcomes such as delayed graft function. OBJECTIVES: To examine the effect of lower-chloride solutions versus normal saline on delayed graft function, hyperkalaemia and acid-base status in kidney transplant recipients. SEARCH METHODS: We searched the Cochrane Kidney and Transplant's Specialised Register to 26 November 2015 through contact with the Information Specialist using search terms relevant to this review. SELECTION CRITERIA: RCTs of kidney transplant recipients that compared peri-operative intravenous lower-chloride solutions to normal saline were included. DATA COLLECTION AND ANALYSIS: Two independent investigators assessed studies for eligibility and risk of bias. Data from individual studies were extracted using standardised forms and pooled according to a published protocol. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. MAIN RESULTS: Six studies (477 participants) were included in the review. All participants were adult kidney transplant recipients and 70% of participants underwent live-donor kidney transplantation. The overall risk of bias was low for selection bias and unclear for remaining domains. There was no difference in the risk of delayed graft function (3 studies, 298 participants: RR 1.03, 95% CI 0.62 to 1.70) or hyperkalaemia (2 studies, 199 participants: RR 0.48, 95% CI 0.04 to 6.10) for participants who received balanced electrolyte solutions compared to normal saline. Intraoperative balanced electrolyte solutions compared to normal saline were associated with higher blood pH (3 studies, 193 participants: MD 0.07, 95% CI 0.05 to 0.09), higher serum bicarbonate (3 studies, 215 participants: MD 3.02 mEq/L, 95% CI 2.00 to 4.05) and lower serum chloride (3 studies, 215 participants: MD -9.93 mmol/L, 95% CI -19.96 to 0.11). There were four cases of graft loss in the normal saline group and one in the balanced electrolyte solution group, and four cases of acute rejection in the normal saline group compared to two cases in the balanced electrolyte solution group. AUTHORS' CONCLUSIONS: Balanced electrolyte solutions are associated with less hyperchloraemic metabolic acidosis compared to normal saline, however it remains uncertain whether lower-chloride solutions lead to improved graft outcomes compared to normal saline.

Hypocalcemia post denosumab in patients with chronic kidney disease stage 4-5.

BACKGROUND: Denosumab, a RANK-ligand inhibitor, is an effective treatment for osteoporosis in postmenopausal women and men. Unlike the bisphosphonates, it is not excreted by the kidney. Little is known, however, about its efficacy and safety in patients with severe chronic kidney disease (CKD). METHODS: A retrospective study was performed in CKD 4-5D patients from a tertiary referral hospital who were treated with denosumab between 1st January 2011 and 31st March 2014. Data collected included information about the following: CKD stage, fracture history, bone mineral density, serum calcium levels pre and post denosumab treatment, episodes of hypocalcemia, relevant medications and adverse events. RESULTS: Eight patients with CKD-5 and 6 patients with CKD-4 were identified (all female, mean age 77.1 ± 9.9). The mean pre-denosumab calcium value was 2.42 ± 0.12 mmol/l, PTH 20.2 ± 14.7 pmol/l and 25-OH vitamin D 69.1 ± 30.1 nmol/l. After denosumab treatment, 6/8 patients with CKD-5/5D, and 2/5 patients with CKD-4 developed severe hypocalcemia. Two patients developed direct adverse complications of hypocalcemia (seizure, laryngospasm, prolonged QTc). Among the patients who developed hypocalcemia, the median time to serum calcium nadir was 21 days and the median time to correction of hypocalcemia was 71 days. Treatment of hypocalcemia required large doses of oral calcium and calcitriol, and increases in dialysate calcium concentration. CONCLUSIONS: A high rate of severe hypocalcemia was observed in patients with advanced CKD treated with denosumab. If denosumab is used in patients with severe CKD, close monitoring and aggressive replacement of calcium and calcitriol is required to avoid the development of hypocalcemia.

The Thiazide-Sensitive Co-Transporter Promotes the Development of Sodium Retention in Mice with Diet-Induced Obesity.

BACKGROUND/AIMS: Intravascular volume expansion due to sodium retention is involved in the pathogenesis of obesity-related hypertension. Institution of high fat diet (HFD) feeding leads to an initial state of positive sodium balance due to enhanced tubular reabsorption of sodium, but which tubular sodium transporters are responsible for this remains undefined. METHODS: C57/Bl6 mice were fed control or HFD for 3 weeks. Blood pressures were recorded by tail cuff method. Sodium transporter expression and phosphorylation were determined by Western blotting. In vivo activity of NCC was determined using natriuretic responses to hydrochlorothiazide. Expression of NCC mRNA was determined using qPCR. RESULTS: At 3 weeks HFD mice had significant weight gains compared to control mice, but blood pressures were not yet elevated. There were no changes in expression or phosphorylation of the bumetanide-sensitive cotransporter, NKCC2, or in expression of subunits of the amiloride-sensitive ion channel, ENaC. However, there were significant increases in mRNA and protein expression of the thiazide-sensitive co-transporter, NCC, in kidneys from HFD mice. Consistent with this, HFD mice had increased in vivo activity of NCC. CONCLUSIONS: Increased expression of NCC promotes the sodium loading response to institution of HFD feeding before onset of hypertension.