The climate impact of dialysis.

PURPOSE OF REVIEW: A reciprocal relationship currently exists between climate change and healthcare, mutually influencing each other. There have been significant planetary shifts in recent decades, marked by escalating temperatures, frequent natural calamities, a disturbing surge in climate-linked fatalities, and a heightened incidence of kidney disease diagnoses. RECENT FINDINGS: Dialysis, a life-preserving treatment for kidney failure, extends to 2-3 million patients globally, mainly through in-centre haemodialysis. This treatment exerts an environmental toll, contributing to the healthcare sector's carbon footprint through water usage, energy consumption, waste generation, and current procurement practices. Diligent scrutiny and data collection of these facets have spurred sustainability initiatives, beginning at the local level with water, energy, and waste management. Still, this represents just the tip of the iceberg, with a pressing need for more comprehensive and habitual sustainable dialysis practices. SUMMARY: This review examines the carbon footprint from dialysis, probes its ecological ramifications, and underscores potential solutions to lessen its climate impact.

Four-Year-Olds Share General Knowledge and Use Generic Language When Teaching.

Young children's receptiveness to teaching is unquestioned, but their understanding of pedagogy has only begun to be explored. Two experiments (N = 90; 45 female) with 4-year-olds from racially and ethnically diverse backgrounds were conducted to test if they exchange general information and use generic language when teaching. Children in both experiments taught more general than episodic information and used more generic than episodic language when teaching. Experiment 2 showed that children did not prefer to report general information or use generic language in a non-pedagogical context. The findings suggest that by 4 years old, children understand that the goal of teaching is to transmit general knowledge.

Anti-GBM Disease after Oxford-AstraZeneca ChAdOx1 nCoV-19 Vaccination: A Report of Two Cases.

There have been reports of rare de novo glomerular diseases following vaccination for coronavirus disease 2019 (COVID-19). We report two cases of anti-glomerular basement membrane (GBM) disease in previously healthy females after Oxford-AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19). The first case was a 69-year-old female who developed lethargy and anuria approximately 8 weeks after her first dose of Oxford-AstraZeneca COVID-19 vaccine. The second case was a 72-year-old female who developed malaise and diarrhoea approximately 3 weeks after her second dose of Oxford-AstraZeneca COVID-19 vaccine. Both cases had severe acute kidney injury, raised anti-GBM antibody titres, and renal biopsies consistent with anti-GBM disease. Both cases were commenced on haemodialysis and treated with high dose glucocorticoids, cyclophosphamide, and plasmapheresis. Neither patient had recovery of renal function, and both remain dialysis dependent. These cases add to the previously reported cases of anti-GBM disease after mRNA COVID-19 vaccination. As more COVID-19 vaccinations are administered worldwide, it would be important for clinicians to be aware of this possible association, and continued surveillance is warranted.

Patient awareness and beliefs about the risk factors and comorbidities associated with chronic kidney disease : A mixed-methods study.

AIM: Diabetes, hypertension and smoking may contribute to the development and progression of chronic kidney disease (CKD) and its complications. The aim of this study was to assess patients' awareness and beliefs about these and other risk factors associated with CKD. METHODS: Participants with CKD Stages 1-5 were purposively sampled for participation in a mixed methods study. Focus group participants completed a survey on CKD risk factors and discussed the reasons for their choices. Thematic analysis was used to analyse the qualitative data. RESULTS: Of the 38 participants, the proportion who identified hypertension, family history, diabetes and obesity as risk factors for CKD were 89%, 87%, 87% and 70% respectively. Only 54% and 38% recognized that smoking and Aboriginal or Torres Strait Islander status were risk factors. Participants considered the risks of heart attack, stroke and premature mortality to be 20-40% lower in people with CKD than those with diabetes or pre-existing cardiovascular disease. Five themes were identified: invisibility (lack of signs and symptoms of CKD), invincibility (participants did not feel they were at risk), lacking awareness (identified not knowing much about their disease), cumulative comorbidities (concerned about the increased risks of associated diseases) and inevitability of death (there is no cure for CKD). CONCLUSION: Participants had good understanding of some risk factors for CKD (hypertension and diabetes) but limited understanding of others. Awareness of comorbidities was also less than for other chronic conditions. Compared with diabetes and cardiovascular disease, CKD was perceived to pose less of a threat to life. Patient education that addresses CKD risk factors, comorbidities and outcomes may increase awareness and foster better self-management for people with CKD.

Knowledge deficit of patients with stage 1-4 CKD: a focus group study.

BACKGROUND: Patients with early-stage chronic kidney disease (CKD) must make lifestyle modifications and adhere to treatment regimens to prevent their progression to end-stage kidney disease. The aim of this study was to elicit the perspectives of patients with stage 1-4 CKD about their disease, with a specific focus on their information needs in managing and living with CKD and its sequelae. METHODS: Patients with CKD stages 1-4 were purposively sampled from three major hospitals in Sydney, Australia to participate in focus groups. Transcripts were thematically analysed. RESULTS: From nine focus groups including 38 participants, six major themes were identified: medical attentiveness (shared decision-making, rapport, indifference and insensitivity); learning self-management (diet and nutrition, barriers to physical activity, medication safety); contextualizing comorbidities (prominence of CKD, contradictory treatment); prognostic uncertainty (hopelessness, fear of disease progression, disbelief regarding diagnosis); motivation and coping mechanisms (engage in research, pro-active management, optimism, feeling normal); and knowledge gaps (practical advice, access to information, comprehension of pathology results and CKD diagnosis, education for general practitioners). CONCLUSION: Patients capacity to slow the progression of CKD may be limited by their lack of knowledge about the disease, its comorbidities, psychosocial influences and their ability to interact and communicate effectively with their health-care provider. Support from a multidisciplinary care team, combined with provision of comprehensive, accessible and practical educational resources may enhance patients' ability and motivation to access and adhere to therapeutic and lifestyle interventions to retard progression of CKD.

Paradoxically Low Levels of Total and HMW Adiponectin in Relation to Metabolic Parameters in a Tongan Population.

Aim. Adiponectin has demonstrated anti-inflammatory and insulin sensitising properties, and low circulating levels may be an important risk factor for diabetes. We examined levels of adiponectin and its insulin-sensitising HMW isoform and their relationship with metabolic parameters in Tongans, a population prone to type II diabetes. Methods. Adiponectin and its HMW isoform were quantitated by Elisa in specimens from a randomly recruited, multistage cluster population survey of Tongans and from a group of Caucasians. Anthropometric, clinical, and biochemical data were collected on each subject. Results. Both male and female Tongans had lower levels of total and HMW adiponectin than their Caucasian counterparts. Levels of total and HMW adiponectin were higher in females than males in each group. Adiponectin levels were inversely related to BMI, weight, and HOMA in Tongan males and females, as well as to dyslipidemia in both sexes. Conclusion. Tongans had lower levels of both total and HMW adiponectin than Caucasians population, even after matching Tongans to their Caucasian counterparts based on BMI, age, and sex. These findings may reflect differences in body composition between the populations not adequately assessed by BMI, lifestyle factors, or a genetic variant likely in a genetically homogenous population.

Factor H binds to the N-terminus of adiponectin and modulates complement activation.

The adipokine adiponectin circulates in high concentration, and activates the classical pathway of complement by binding C1q, leading to the activation of C3 and formation of the membrane attack complex. Such behaviour is potentially pathophysiological. However, we showed adiponectin captured the complement inhibitor Factor H both as a pure protein and from human serum. Both heparin and a homologue of C3b, substrates binding to the C-terminus of Factor H, were inhibitory of the interaction, as was EDTA. Factor H bound equivalently to high and low molecular weight serum adiponectin, and to an N-terminal 16 kDa cyanogen bromide cleavage product of adiponectin. The binding of Factor H inhibited both the C3 and C5 convertases generated from complement activation by adiponectin, so reducing potentially pathophysiological consequences such as the deposition of C5b-9, while allowing opsonisation of target molecules with C3b.

Adiponectin is present in the urine in its native conformation, and specifically reduces the secretion of MCP-1 by proximal tubular cells.

AIM: To determine whether adiponectin detected in urine is present in its native form and if adiponectin receptors (AdipoR) present and functional in proximal tubular (HK-2) cells. BACKGROUND: Adiponectin is a protein with anti-inflammatory, anti-atherogenic and insulin-sensitizing properties. It has previously been detected antigenically in the urine in several forms of renal disease. METHODS: We compared the isoform distribution of urinary adiponectin in patients with proteinuric and non-proteinuric renal disease with that of matched controls using chromatography and enzyme-linked immunosorbent assay. We examined whether AdipoR were present in HK-2 cells by real-time reverse transcription polymerase chain reaction. Their functionality was investigated by determining the effect of recombinant adiponectin on adenosine monophosphate-activated protein kinase phosphorylation using western blotting, and on the secretion of monocyte chemotactic protein-1 and C3 using enzyme-linked immunosorbent assays. RESULTS: Adiponectin in the urine is physiologically intact and largely present as the low molecular weight isoform. Subjects with urinary protein >150 mg/L excreted significantly more adiponectin and its high and low molecular weight isoforms than those with <150 mg/L. mRNA for AdipoR were present in HK-2 cells, with levels of mRNA for AdipoR1 being 20 times greater than those for AdipoR2. Ligation of AdipoR on proximal tubular cells increased phosphorylation of adenosine monophosphate-activated protein kinase, and downregulated the secretion of the inflammatory cytokine monocyte chemotactic protein-1, but not of C3. CONCLUSION: Physiologically relevant isoforms of adiponectin are present in the urine of normal subjects and those with proteinuria. In addition, functional receptors for adiponectin are present in HK-2 cells. Abnormal levels of adiponectin in the urine may therefore activate these receptors, potentially resulting in anti-inflammatory activity.

Adiponectin binds C1q and activates the classical pathway of complement.

The adipose-specific protein adiponectin binds to a number of target molecules, including damaged endothelium and the surface of apoptotic cells. However, the significance of this binding remains unclear. This study demonstrates the binding of purified C1q to recombinant adiponectin under physiological conditions, and the dependence of this upon Ca(++) and Mg(++). Binding was enhanced by metaperiodate-mediated destruction of glucosylgalactosyl sugars on adiponectin. Adiponectin was bound by the globular domain of the A chain of collagenase-digested C1q, and C1q binding induced deposition of C4 and C3 through activation of the classical complement pathway. After Western blotting, affinity-purified adiponectin from human serum bound C1q, whereas adiponectin in whole serum did not, unless pre-treated with metaperiodate. These results suggest adiponectin is member of the pattern-recognition family of defence collagens, able to bind target molecules and activate complement. It may therefore play an important role in innate immunity and autoimmune phenomena.

Review article: Adiponectin: its role in kidney disease.

The multifactorial glycoprotein, adiponectin has demonstrable insulin-sensitizing, anti-atherogenic and anti-inflammatory properties. However, despite the prevalence of both insulin-resistance and vascular disease in patients with end-stage kidney disease, levels of adiponectin are high. Adiponectin circulates in different sizes (the high-molecular-weight (HMW) isoform is thought to be the most insulin-sensitizing type) and binds to two receptors, adiponectin receptors (AdipoR) 1 and 2. The adiponectin/receptor system appears to be upregulated in end-stage kidney disease possibly as an appropriate counter-regulatory response to the uraemic milieu. In contrast, adiponectin and its HMW isoform, AdipoR mRNA expression on peripheral blood mononuclear cells decrease after kidney transplantation, likely secondary to immunosuppression and/or an improvement in glomerular filtration rate and the uraemic environment. Adiponectin has also been detected in the urine of patients with proteinuric kidney disease. The presence of AdipoR on an immortal cell line of proximal tubular epithelial cells (HK-2) and an increased amount of intact HMW isoform in the urine of patients with various forms of proteinuria lead us to speculate about the potential role of urinary adiponectin. This review will also discuss the structure and function of adiponectin and its potential relevance to patients with kidney disease and the different factors that may influence the metabolism of this protein in kidney failure.

The effect of renal transplantation on adiponectin and its isoforms and receptors.

Insulin resistance (IR) and other proatherogenic risk factors associated with end-stage kidney disease (ESKD) are improved by renal transplantation. Adiponectin is a protein with insulin-sensitizing, anti-inflammatory, and antiatherogenic properties. It exists in several isoforms, but the high molecular weight (HMW) isoform correlates best with insulin sensitivity. Paradoxically, the levels of this protein and its HMW isoform are increased in ESKD. We measured the homeostasis model assessment for insulin resistance (HOMA-IR), plasma adiponectin and its isoforms, and messenger RNA for adiponectin receptors (AdipoR1 and AdipoR2) on peripheral blood mononuclear cells in 54 stable transplant recipients, 50 patients established on hemodialysis, and 52 controls; groups were matched for body mass index and sex. HOMA-IR values were significantly higher in patients with ESKD compared with controls (P < .0005) and transplant patients (P < .05) but there was no difference between the latter 2 groups. Adiponectin levels were also higher in patients with ESKD compared with controls (P < .0005), and although levels were lower in the transplant group, they remained higher than in controls (P < .0001). However, although the absolute amount of HMW isoform in transplant patients remained higher than in controls (P < .0001), the proportion was similar, and less than in patients with ESKD (P < .005). The absolute amount of the HMW isoform correlated with superior metabolic indices in all 3 cohorts. AdipoR1 and AdipoR2 messenger RNA levels after transplantation were significantly lower than those of ESKD subjects (P < .0001, P < .01), but transplant patients had less AdipoR1 than controls, although their AdipoR2 levels were higher. AdipoR1 correlated with AdipoR2 in all 3 cohorts. We conclude that HOMA-IR was lower in the transplant group compared with the group on hemodialysis and this coincided with lower total adiponectin levels and absolute amount of the HMW isoform and AdipoR on peripheral blood mononuclear cells. Lower AdipoR after transplantation may be secondary to immunosuppression and/or an improvement in glomerular filtration rate and the uremic milieu.

Glycosylation of human adiponectin affects its conformation and stability.

The collagenous region of adiponectin is glycosylated in vitro with glucosylgalactosyl moieties on four conserved lysines. We investigated the glycosylation of human adiponectin in vivo. Sugar vicinyl hydroxides on adiponectin were oxidized with 10 or 1 mM metaperiodate, and the result analyzed by two-dimensional electrophoresis and immunoblotting. Only 10 mM metaperiodate caused significant changes in electrophoretic mobility and an altered susceptibility to proteinase K digestion. Such treatment also increased the susceptibility of hexamers and high molecular weight (HMW) isoforms to dissociation by SDS. By contrast, untreated low molecular weight (LMW) isoforms were readily dissociated by low concentrations of SDS. Reduced HMW isoforms were able to partially reassemble following the removal of dithiothreitol, and this process was unaffected by metaperiodate. The presence of sialic acid was detected by Maackia amurensis Lectin II blotting, and by oxidation with 1 mM metaperiodate, followed by detection with Emerald Green 300 fluorescent dye. Quantitation of sugars on affinity-purified adiponectin from nine human plasmas showed that dimers of HMW isoforms contained a 1.3-fold greater amount of total sugar than LMW isoforms. However, both contained similar amounts of sialic acid. We conclude that glucosylgalactosyl residues contribute to the conformation of HMW human plasma adiponectin. In addition, the HMW isoform contains greater amounts of glucosylgalactosyl residues than the LMW isoform, and these sugars are important in determining its stability in vivo.

Up-regulation of adiponectin, its isoforms and receptors in end-stage kidney disease.

BACKGROUND: Despite the favourable effects of adiponectin on the vasculature and insulin resistance (IR), levels are increased in patients with end-stage kidney disease (ESKD), in whom both IR and atherosclerosis are prevalent. METHODS: To investigate this paradox, we examined the distribution of adiponectin isoforms, the expression of adiponectin receptor (AdipoR) mRNA on peripheral blood mononuclear cells (PBMC) in 41 patients with ESKD on haemodialysis and 41 matched controls, and its function by adenosine monophosphate-activated protein kinase (AMPK) phosphorylation of AdipoR on PBMC. We also compared the expression of AdipoR on PBMC with that on muscle and subcutaneous and visceral fat in 10 patients undergoing elective cholecystectomy. RESULTS: The proportion of the high molecular weight (HMW) isoform of adiponectin was increased in the dialysis group (P = 0.001), even though these patients were significantly insulin resistant compared with controls (P = 0.006). AdipoR1 and AdipoR2 on PBMC were also increased in patients with ESKD (P < 0.05 and P = 0.007, respectively), but levels did not correlate with IR, the HMW isoform or other anthropometric measurements. There was a strong correlation between AdipoR1 and AdipoR2 on PBMC in ESKD and in subcutaneous and visceral fat in controls. However, there was no relationship between AdipoR in PBMC, muscle or visceral fat. Phosphorylation of AMPK by recombinant adiponectin showed that AdipoR on PBMC, from controls and ESKD patients, were equally functional. CONCLUSIONS: IR in ESKD is not explained by the change in isoformic distribution, or by AdipoR down-regulation or dysfunction. Rather, this receptor-ligand axis is up-regulated and may be a beneficial response to the inflammatory milieu of ESKD.

Human adiponectin binds to bacterial lipopolysaccharide.

Adiponectin has anti-inflammatory and anti-atherogenic properties in addition to its acknowledged roles in insulin sensitivity and energy homeostasis. These properties include the suppression of lipopolysaccharide [LPS]-mediated inflammatory events. We demonstrated that both recombinant and native adiponectin directly bind LPS derived from three different bacteria. The interaction occurred at pH 5.0-6.0 and was inhibited by the presence of Ca(2+) and Mg(2+), but enhanced by the sequestration of these cations. Maximal binding occurred at pH 6.0 in the presence of ethylenediaminetetraacetic acid. Lipid A and C1q were not inhibitory, although LPS, heparin, zymosan, and individual sugars all inhibited the reaction. Periodate-mediated deglycosylation of adiponectin, and reduction and alkylation also inhibited binding. Since adiponectin infiltrates into [relatively] acidic sites of inflammation, it may act as a scavenging anti-inflammatory agent in atherosclerosis and vascular damage where LPS [and other pro-inflammatory molecules] are present.

Should we quantify insulin resistance in patients with renal disease?

Cardiovascular disease is a major cause of morbidity and mortality in dialysis patients. Vascular disease develops before the initiation of dialysis, and it is now recognized that chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease. Death from cardiovascular disease is a more common endpoint of CKD than progression to dialysis. There are multiple mechanisms that contribute to the increased vascular risk of CKD, one of which is the presence of insulin resistance (IR). CKD is characterised by many features of the metabolic syndrome, and features of IR are also observed in dialysis and transplant patients. IR may be quantified by several different methods. One such method is homeostatic model assessment (HOMA) technique, which derives a measurement of IR from fasting plasma glucose and insulin concentrations. The HOMA index has been demonstrated to be an independent predictor of survival in dialysis patients. CKD is characterised by a chronic inflammatory response and abnormalities in the production and regulation of adipose tissue derived proteins, which may contribute to the development of IR. There are a range of interventions including diet and exercise programmes or medications that may influence IR; however, the impact of these interventions in the context of CKD has not been systematically evaluated.

The metabolism of isoforms of human adiponectin: studies in human subjects and in experimental animals.

OBJECTIVE: Little is known of the metabolism of different isoforms of adiponectin. We therefore (a) characterised the size distribution of human adiponectin in relation to gender, body composition and following a challenge with a fat meal or oral glucose in humans, and (b) studied the metabolism of isoforms of human adiponectin in rabbits. METHOD: Electrophoresis, blotting and chromatography were used to characterise human adiponectin in 36 healthy subjects, including 15 with at least two first-degree relatives with type 2 diabetes, before and after consumption of a fatty meal or glucose. The metabolism of column-fractionated human adiponectin was studied in rabbits, some of which were coinjected with insulin. RESULTS: Females had a higher proportion of high molecular weight (HMW) and hexameric adiponectin (P = 0.002 and 0.004 respectively), and a lower proportion of trimers (P < 0.0001) than males. Females also showed a strong negative relationship between body fat measures and the proportion of HMW adiponectin. There were no differences in isoforms between insulin-resistant and -sensitive subjects, or following oral glucose or a fat meal. Adiponectin in rabbits had an extravascular/intravascular ratio of 0.71, and a half-life (T1/2) of 14.3 h. Metabolism was not influenced by insulin or reduction of sulphydryl bonds. HMW and trimeric isoforms had a significantly different T1/2 of 13.0 and 17.5 h respectively (P < 0.05), and these isoforms did not interconvert in vivo. CONCLUSIONS: Human adiponectin is present as trimers, hexamers and HMW forms. Females had a higher proportion and absolute amount of HMW species compared with males, and female, but not male, subjects showed a strong negative relationship between measures of body fat, and the proportion of HMW species. These isoforms did not respond to challenge in man with a fatty meal or oral glucose, and in the rabbit, to injected insulin. HMW adiponectin was more rapidly metabolised than the trimeric form, but both were stable in vivo, and did not interconvert. We conclude that human adiponectin is much longer-lived than is the case with other hormones, a finding with positive implications for the potential to supplement levels of adiponectin in man.

Outcome of overseas commercial kidney transplantation: an Australian perspective.

Lack of donors has led to a worldwide increase in commercial kidney transplantation programs where recipients acquire kidneys either from executed prisoners or live non-related donors. Commercial transplantation is prohibited by legislation in Australia. Our centres have had 16 patients who have travelled overseas to receive a commercial kidney transplant; five have subsequently died. As has been found previously, patients who received commercial transplants were more likely to develop infections such as HIV, hepatitis B virus, cytomegalovirus and fungal infections. Previous reports have found that patient and graft survival were comparable to local results, whereas we found that patient and graft survival were worse than transplantation within Australia. Patients considering the option of overseas commercial donation should be advised that heightened risks to life and graft survival exist.

Renal imaging in pyelonephritis.

BACKGROUND: Pyelonephritis accounts for a significant number of hospital admissions. It is unclear from existing literature whether all patients requiring admission to hospital should undergo renal imaging or if there is a subset that indicates clinical parameters for those who are more likely to have significant renal imaging abnormalities. METHOD AND RESULTS: We undertook a retrospective study of 60 consecutive patients hospitalized with pyelonephritis, the majority of whom underwent renal ultrasound at the time of admission. Clinical data collected included age, sex, fever, serum creatinine, days for resolution of fever, premorbid conditions, and results of renal imaging. Sixteen per cent were found to have new and clinically significant abnormal findings; predominantly, urinary tract obstruction. We found no significant difference between the groups with abnormal and normal renal imaging in terms of any easily detectable clinical parameter such as change in serum creatinine, premorbid conditions, age, days for fever to resolve or white cell count on admission. We found a high proportion of Escherichia coli resistant to ampicillin (46%) but not to amoxycillin/clavulinic acid. CONCLUSION: Although our study did not test whether immediate imaging is more advantageous than delaying imaging for those who fail to respond to treatment, our findings suggest that early imaging is a cost-effective part of management. On the basis of these data, we recommend renal imaging for all patients requiring hospital admission for pyelonephritis, and suggest that initial empirical therapy should include an intravenous dose of cephalosporin but not ampicillin.