Hemodialysis

Beta-2 Microglobulin Amyloidosis: Past, Present, and Future

Almost half a century has elapsed since the first description of dialysis-related amyloidosis (DRA), a disorder caused by excessive accumulation of β-2 microglobulin (B2M). Within that period, substantial advances in RRT occurred. These improvements have led to a decrease in the incidence of DRA. In many countries, DRA is considered a "disappearing act" or complication. Although the prevalence of patients living with RRT increases, not all will have access to kidney transplantation. Consequently, the number of patients requiring interventions for treatment of DRA is postulated to increase. This postulate has been borne out in Japan, where the number of patients with ESKD requiring surgery for carpal tunnel continues to increase. Clinicians treating patients with ESKD have treatment options to improve B2M clearance; however, there is a need to identify ways to translate improved B2M clearance into improved quality of life for patients undergoing long-term dialysis.

The influence of haemodialysis on CD4+ T-cell counts in people living with human immunodeficiency virus with end-stage kidney disease

Background

In South Africa it is estimated that 7.9 million people are living with human immunodeficiency virus (HIV). HIV is associated with an increased risk of kidney disease. For people living with HIV (PLWH) who develop end-stage kidney disease (ESKD), access to renal replacement therapy can be difficult. Kidney transplantation is a cost-effective option, with improved overall survival and better quality of life. In Johannesburg, the eligibility criteria for kidney transplantation include a sustained CD4+ T-cell count of > 200 cells/μL and suppressed HIV replication.

Objective

To investigate the influence of haemodialysis on the lymphocyte subsets in PLWH with ESKD. In addition, all available %CD4+ T-cell counts, absolute CD4+ T-cell counts and viral load measurements were collected to assess the longitudinal trends of these measurements in PLWH with ESKD.

Methods

This was a cross-sectional study comparing two groups. The HIV-infected study participants (n = 17) and HIV-uninfected controls (n = 17) were recruited from renal dialysis centres in Johannesburg from 2017 to 2018. Demographic data and social data were collected from all the study participants (n = 17). Blood samples were collected from all the study participants (before and after a haemodialysis session), and the lymphocyte subsets were then measured. The available longitudinal data for the serial CD4+ T-cell counts and HIV viral loads were collected (n = 14).

Results

Our cohort showed a statistically significant increase in the post-dialysis percentage of CD4+ T cells (5%, p < 0.001) and the absolute CD4+ T-cell counts (21 cells/µL, p < 0.03). The longitudinal trend analysis for the percentage of CD4+ T cells revealed a significant increase in five participants (36%), and a single patient (7%) had a significant decrease in the longitudinal trend analysis for the absolute CD4+ T-cell counts. The longitudinal trend analysis for HIV viral load revealed the majority of our participants were not virologically suppressed.

Conclusion

This study showed that haemodialysis does not have an immediate negative impact on CD4+ T-cell count, suggesting that immunologic recovery is not impeded by treatment of the underlying ESKD.

Saliva as a tool for monitoring hemodialysis: a systematic review and meta-analysis

This study aimed to assess whether the reductions in serum urea and creatinine levels are different from the reductions in salivary urea and creatinine levels that occur after hemodialysis in chronic renal patients. The systematic review protocol was registered in the PROSPERO database. Eight databases were searched to identify pretest-posttest studies of chronic kidney disease patients undergoing hemodialysis, with no language or year restrictions. The JBI Critical Appraisal Tool was used to assess the risk of bias. Meta-analyses using random-effect models were conducted to compare salivary and serum correlations and to pooled mean and proportion differences from pre- to posthemodialysis urea and creatinine levels by subgroup analysis. The I2 test was used to assess heterogeneity, and a meta-regression was performed to statistically assess correlations and differences in the pooled effects pre- and postdialysis. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence. The search resulted in 1404 records, and only six studies (n = 252 participants) fulfilled the eligibility criteria and were included. The studies were published between 2013 and 2018. All studies showed a significant reduction in both salivary and serum urea/creatinine levels. All eligible studies presented a low risk of bias. The meta-analysis shows a moderate to high correlation between salivary and blood levels of urea (r: 0.79; 95% CI: 0.56-1.00) and creatinine (r: 0.64; 95%CI: 0.16-1.00), with a very low level of certainty. The reductions in salivary urea and creatinine levels are similar to and correlated with the reductions in blood urea and creatine levels after hemodialysis among chronic kidney disease patients.

Denosumab Recovers Aortic Arch Calcification During Long-Term Hemodialysis

Introduction

Aortic arch calcification (AoAC) is related closely to mortality risk in patients undergoing maintenance dialysis. Recent experimentally obtained data suggest that osteoprotegerin/receptor activator for nuclear factor κB ligand signal transmission plays a role in de novo chondrogenic transition of vascular cells leading to calcification that is unrelated to bone metabolism. This study investigated the long-term effects of denosumab, an osteoprotegerin mimic peptide, on AoAC.

Methods

This study examined 58 patients with an 8 year vintage of dialysis at 1 center for observational study during 2009 to 2020. Denosumab was administered to 28 patients every 6 months. Blood chemical data were used. AoAC proportions were measured using a simple but computed tomography–equivalent computer-based chest X-ray analysis (calcified pieces of areas around the aorta).

Results

Blood chemical data of the control and denosumab groups that did not differ at the start showed differences of mineral metabolism after 30 months of observation. Remarkably, the AoAC proportion increased from 29.4% to 46.25% in the control group but decreased significantly from 25.0% to 20.0% (P < 0.01) in the denosumab group. Denosumab effects on decalcification were not observed 12 months after initiation.

Conclusion

We conclude that long-term use of denosumab is effective to reverse or treat AoAC in patients undergoing hemodialysis.

An LC-MS/MS analytical method for the determination of uremic toxins in patients with end-stage renal disease

End-stage renal disease (ESRD) is the last stage of chronic kidney disease, characterized by the progressive accumulation of uremic toxins (UTs). Hemodialysis is the standard approach to remove UTs from the body. Creatinine and urea levels are important indices of hemodialysis effectiveness, but the utility of those markers to estimate the removal of UTs, especially protein-binding UTs is limited. We developed an LC-MS/MS method for the quantification of UTs and to provide markers for evaluating hemodialysis effectiveness. These substances were extracted from serum samples after acetonitrile precipitation of protein and then separated on a HILIC column. The flow rate was 0.6 mL/min with a run time of 8.0 min for the negative ion mode and positive ion mode each. In this study 26 UTs were determined in normal subjects and in patients with ESRD before and after hemodialysis; serum levels were significantly higher in patients with ESRD than in subjects with normal renal function. A significant decrease in a variety of serum UTs were observed in patients after dialysis treatment, but no change in the levels of orotic acid, CMPF, kynurenic acid, p-cresol sulfate, phenyl-β-d-glucuronide, 4-ethylphenyl sulfate and 3-indolyl-β-d-glucopyranoside was found. These results show that some UTs could not be completely removed by hemodialysis. In addition, some biomarkers of different types of UTs are proposed for evaluating hemodialysis effectiveness.

Serum trace metal association with response to erythropoiesis stimulating agents in incident and prevalent hemodialysis patients

Alterations in hemodialysis patients' serum trace metals have been documented. Early studies addressing associations levels of serum trace metals with erythropoietic responses and/or hematocrit generated mixed results. These studies were conducted prior to current approaches for erythropoiesis stimulating agent (ESA) drug dosing guidelines or without consideration of inflammation markers (e.g. hepcidin) important for regulation of iron availability. This study sought to determine if the serum trace metal concentrations of incident or chronic hemodialysis patients associated with the observed ESA response variability and with consideration to ESA dose response, hepcidin, and high sensitivity C-reactive protein levels. Inductively-coupled plasma-mass spectrometry was used to measure 14 serum trace metals in 29 incident and 79 prevalent dialysis patients recruited prospectively. We compared these data to three measures of ESA dose response, sex, and dialysis incidence versus dialysis prevalence. Hemoglobin was negatively associated with ESA dose and cadmium while positively associated with antimony, arsenic and lead. ESA dose was negatively associated with achieved hemoglobin and vanadium while positively associated with arsenic. ESA response was positively associated with arsenic. Vanadium, nickel, cadmium, and tin were increased in prevalent patients. Manganese was increased in incident patients. Vanadium, nickel, and arsenic increased with time on dialysis while manganese decreased. Changes in vanadium and manganese were largest and appeared to have some effect on anemia. Incident and prevalent patients' chromium and antimony levels exceeded established accepted upper limits of normal.

Secular Changes in Mortality and Hospitalization over Time in People with Kidney Failure or Severe CKD as Compared with Other Noncommunicable Diseases

BACKGROUND

Few new treatments have been developed for kidney failure or CKD in recent years, leading to perceptions of slower improvement in outcomes associated with CKD or kidney failure than for other major noncommunicable diseases.

METHODS

Our retrospective cohort study included 548,609 people with an incident noncommunicable disease, including cardiovascular diseases, diabetes, various cancers, and severe CKD or kidney failure treated with renal replacement (KF-RRT), treated in Alberta, Canada, 2004-2015. For each disease, we assessed presence or absence of 8 comorbidities; we also compared secular trends in relative (compared to a referent year of 2004) and absolute risks of mortality and mean annual days in the hospital associated with each disease after 1 year and 5 years.

RESULTS

Comorbidities increased significantly in number over time for all noncommunicable diseases except diabetes, and increased most rapidly for CKD and KF-RRT. Significant but relatively small reductions over time in the risk ratio of mortality at 1 year occurred for nearly all noncommunicable diseases. Secular trends in the absolute risk of mortality were similar; CKD and KF-RRT had a relatively favorable ranking at 1 year. Breast cancer, KF-RRT, diabetes, and colorectal cancer displayed the largest relative reductions in number of hospital days at 1 year. Significant absolute reductions in the number of hospital days were observed for both KF-RRT and CKD; the former had the highest absolute reduction among all noncommunicable diseases. Results were similar at 5 years.

CONCLUSIONS

We observed secular reductions in mortality and annual hospital days at 1 year and 5 years among incident patients with KF-RRT and severe CKD, as well as several other common noncommunicable diseases.

Older Age and High Serum Ferritin Levels Associated With the Risk of Chronic Cytopenia in Hemodialysis Patients

Leukopenia or thrombocytopenia is sometimes observed in end-stage renal disease (ESRD) patients, but the association between chronic leukopenia or thrombocytopenia and hemodialysis (HD) is still unclear. We aimed to investigate the incidence of chronic leukopenia or thrombocytopenia in patients with ESRD who received HD and to determine the risk factors of this complication. We retrospectively analyzed ESRD patients treated with HD at Ditmanson Medical Foundation Chia-Yi Christian Hospital in 2018. The risk factors for the occurrence of chronic leukopenia and thrombocytopenia were analyzed by Cox regression models. Of the 473 patients in our study cohort, 46 (9.7%) patients had a hematologic abnormality, including 18 patients with chronic leukopenia, 18 with chronic thrombocytopenia, and 10 with pancytopenia. Multivariate analysis revealed that patient age ≥60 years at the initiation of dialysis was a significant predictor for both chronic leukopenia [adjusted hazard ratio (aHR), 2.71; 95% confidence interval (CI), 1.06-6.89] and chronic thrombocytopenia (aHR, 2.83; 95% CI, 1.08-7.35). Chronic liver disease (aHR, 3.31; 95% CI, 1.27-8.61) and serum ferritin levels >800 mg/dl (aHR, 3.29; 95% CI, 1.29-8.39) were risk factors for chronic thrombocytopenia. A trend showed that vitamin D from intravenous supplementation (aHR, 0.13; 95% CI, 0.01-1.16, P = 0.066) and serum phosphorous level (aHR, 0.73; 95% CI, 0.53-1.02, P = 0.068) may be associated with chronic thrombocytopenia. Our study demonstrated that hematological abnormality was a long-term complication of HD. These results reveal that older patients with HD and high serum ferritin levels are at an elevated risk for chronic cytopenia. Healthcare professionals should be aware of this risk when treating HD patients in order to improve their prognosis.

Understanding How Nutrition Literacy Links to Dietary Adherence in Patients Undergoing Maintenance Hemodialysis: A Theoretical Exploration Using Partial Least Squares Structural Equation Modeling

Dietary non-adherence is pervasive in the hemodialysis (HD) population. Health literacy is a plausible predictor of dietary adherence in HD patients, but its putative mechanism is scarcely studied. Thus, this study aimed to establish the causal model linking nutrition literacy to dietary adherence in the HD population. This was a multi-centre, cross-sectional study, involving 218 randomly selected multi-ethnic HD patients from nine dialysis centres in Klang Valley, Malaysia. Dietary adherence and self-management skills were assessed using validated End-Stage Renal Disease Adherence Questionnaire and Perceived Kidney/Dialysis Self-Management Scale, respectively. Validated self-developed scales were used to gauge nutrition literacy, dietary knowledge and Health Belief Model constructs. Relationships between variables were examined by multiple linear regressions and partial least squares structural equation modeling. Limited nutrition literacy was evident in 46.3% of the HD patients, associated with older age, lower education level, and shorter dialysis vintage. Dietary adherence rate was at 34.9%. Nutrition literacy (β = 0.390, p < 0.001) was an independent predictor of dietary adherence, mediated by self-efficacy (SIE = 0.186, BC 95% CI 0.110-0.280) and self-management skills (SIE = 0.192, BC 95% CI 0.103-0.304). Thus, nutrition literacy-enhancing strategies targeting self-efficacy and self-management skills should be considered to enhance dietary adherence in the HD population.

Salivary microbiome in patients undergoing hemodialysis and its associations with the duration of the dialysis

Background

Chronic kidney disease (CKD) patients, especially those with end stage renal disease (ESRD) undergoing hemodialysis (HD), exhibit high prevalence of periodontitis. This cross-sectional study aimed to investigate the periodontal status of HD patients and its relationship with salivary microbiome.

Methods

One hundred eight HD patients and one hundred healthy control individuals were recruited. They were subjected to periodontal examination followed by saliva samples collection for 16S rRNA gene sequencing.

Results

The HD patients were with worse periodontal health status, and exhibited higher salivary microbial diversity and lower richness. The periodontal pathogens were significantly enriched in the HD patients. The inferred functional analyze showed microbes enriched in the HD patients were mainly related to metabolism. Despite the periodontal status and overall structure of the microbiome were not significantly altered as the HD duration prolonged, the abundance of Lachnospiraceae [G-2] sp. |HMT_096| is positively correlated with the duration of HD and the community periodontal index (CPI). Five OTUs (operational taxonomic units) belonging to the phyla Firmicutes were enriched as the duration prolonged, and four OTUs originated from the phyla Proteobacteria were negatively related with the CPI index. ESRD patients undergoing HD exhibited microbiota structural, compositional and functional differences compared with the healthy controls. And the species changed as the duration of hemodialysis prolonged.

Conclusions

End stage renal disease changes salivary microbiome and is a risk factor for oral dysbiosis.

Exploring the Relationship Between Patient Activation, Treatment Satisfaction, and Decisional Conflict in Patients Approaching End-Stage Renal Disease

BACKGROUND

Patients approaching end-stage renal disease (ESRD) experience a high level of decisional conflict because they are often not provided with sufficient support and information regarding different treatment options prior to renal failure. Decisional conflict is an important correlate of treatment satisfaction, as it is associated with disease- and treatment-related knowledge that can inform decision-making. Patient activation, the willingness and ability to independently manage one's own health and healthcare, is an individual difference factor that may have important mitigating effects on decisional conflict.

PURPOSE

To identify modifiable factors that may enhance the decision-making process in patients approaching ESRD by exploring potential mediational effects between decisional conflict, treatment satisfaction, and patient activation.

METHODS

Sixty-four patients approaching ESRD completed self-report measures (32% response rate). Measures included the Decisional Conflict Scale, the Kidney Disease Treatment Questionnaire, and the Patient Activation Measure Short Form.

RESULTS

There was a high level of self-reported decisional conflict in this sample. Linear regressions revealed main effects among treatment satisfaction, patient activation, and decisional conflict. These variables were entered into PROCESS to assess a mediational pattern. Results showed that higher chronic kidney disease-related treatment satisfaction predicted lower decisional conflict through higher patient activation in a statistical mediational relationship.

CONCLUSIONS

While the link between treatment satisfaction and decision-making is well established, these results suggest this relationship might be partially explained by patient activation, a potentially modifiable process in patients approaching ESRD. Therefore, interventions that encourage patients to become actively involved in their care could also reduce decisional conflict among patients approaching ESRD.

Abnormalities in gut microbiota and serum metabolites in hemodialysis patients with mild cognitive decline: a single-center observational study

RATIONALE

Although a growing body of evidence indicates that the scores of cognitive function in hemodialysis patients are significantly lower than those of healthy individuals, underlying mechanisms have not been fully elucidated.

OBJECTIVES

To investigate the roles of gut microbiota and serum metabolites in hemodialysis patients with mild cognitive decline (MCD).

METHODS

A total of 30 healthy individuals and 77 hemodialysis patients were enrolled and were classified into healthy control (HC), normal cognitive function (NCF), and MCD groups by evaluation of Montreal Cognitive Assessment. Fecal samples were analyzed by 16S rRNA and serum samples were analyzed by gas chromatography-mass spectrometry from all subjects.

RESULTS

The 16S rRNA study demonstrated that the gut microbiota profiles, including α- and β-diversity, and a number of 16 gut bacteria were significantly altered in the MCD group compared with those in HC or those with NCF. A metabonomics study showed that a total of 29 serum metabolites were altered in the MCD group. Receiver operating characteristic curves showed that Genus Bilophila and serum putrescine might be sensitive biomarkers to indicate MCD in patients with hemodialysis.

CONCLUSIONS

These findings demonstrate gut microbiota and serum metabolites were probably involved in the pathogenesis of hemodialysis-related MCD. Therapeutic strategies targeting abnormalities in gut microbiota and serum metabolites may facilitate the beneficial effects for hemodialysis patients with MCD.

Association between circulating tumor necrosis factor receptors and oral bacterium in patients receiving hemodialysis: a cross-sectional study

BACKGROUND

High levels of tumor necrosis factor (TNF) receptors (TNFRs; TNFR1 and TNFR2), markers of inflammation, have been reported as significant predictors of mortality in hemodialysis patients. Porphyromonas gingivalis is a major pathogenic bacterium involved in periodontitis, which induces systemic inflammation. We investigated the association between the abundance of P. gingivalis in saliva and serum TNFR levels in hemodialysis patients.

METHODS

A cross-sectional study was conducted on 121 hemodialysis patients visiting a clinic in the Tokyo metropolitan area. Medical interviews and examinations, comprehensive dental examinations, bacterial examinations for P. gingivalis in saliva, and measurements of circulating TNFR levels were conducted. Multiple linear regression analysis was performed to evaluate the association between the number of P. gingivalis and circulating TNFR levels.

RESULTS

TNFR1 and TNFR2 were positively correlated with high-sensitivity C-reactive protein (hsCRP). Severe periodontitis was significantly associated with the number of P. gingivalis in saliva but not serum TNFR levels. The number of P. gingivalis was significantly associated with both TNFR1 and TNFR2 levels in sera after adjusting for age, sex, body mass index, smoking status, history of diabetes, prior cardiovascular disease events, serum levels of hsCRP and albumin, and severity of periodontitis [for TNFR1: coefficient 0.76, 95% confidence interval (CI) 0.14-1.37, p = 0.02; for TNFR2: coefficient 0.95, 95% CI 0.09-1.80, p = 0.03].

CONCLUSION

Circulating TNFR levels are associated with the number of P. gingivalis in saliva after adjusting for relevant clinical factors.

Renal Contributions in the Pathophysiology and Neuropathological Substrates Shared by Chronic Kidney Disease and Alzheimer's Disease

Chronic kidney disease and Alzheimer's disease are chronic conditions highly prevalent in elderly communities and societies, and a diagnosis of them is devastating and life changing. Demanding therapies and changes, such as non-compliance, cognitive impairment, and non-cognitive anomalies, may lead to supplementary symptoms and subsequent worsening of well-being and quality of life, impacting the socio-economic status of both patient and family. In recent decades, additional hypotheses have attempted to clarify the connection between these two diseases, multifactorial in their nature, but even so, the mechanisms behind this link are still elusive. In this paper, we sought to highlight the current understanding of the mechanisms for cognitive decline in patients with these concurrent pathologies and provide insight into the relationship between markers related to these disease entities and whether the potential biomarkers for renal function may be used for the diagnosis of Alzheimer's disease. Exploring detailed knowledge of etiologies, heterogeneity of risk factors, and neuropathological processes associated with these conditions opens opportunities for the development of new therapies and biomarkers to delay or slow their progression and validation of whether the setting of chronic kidney disease could be a potential determinant for cognitive damage in Alzheimer's disease.

Tacrolimus trough levels higher than 6 ng/mL might not be required after a year in stable kidney transplant recipients

Background

Little is known regarding optimal tacrolimus (TAC) trough levels after 1 year post-transplant in stable kidney transplant recipients (KTRs) who have not experienced renal or cardiovascular outcomes. This study aimed to investigate the effect of 1-year post-transplant TAC trough levels on long-term renal and cardiovascular outcomes and opportunistic infections in stable KTRs.

Methods

KTRs receiving TAC with mycophenolate-based immunosuppression who did not experience renal or cardiovascular outcomes within 1 year post-transplant were enrolled from a multicenter observational cohort study. Renal outcome was defined as a composite of biopsy-proven acute rejection, interstitial fibrosis and tubular atrophy, and death-censored graft loss. Cardiovascular outcome was defined as a composite of de novo cardiomegaly, left ventricular hypertrophy, and cardiovascular events. Opportunistic infections were defined as the occurrence of BK virus or cytomegalovirus infections.

Results

A total of 603 eligible KTRs were divided into the low-level TAC (LL-TAC) and high-level TAC (HL-TAC) groups based on a median TAC level of 5.9 ng/mL (range 1.3–14.3) at 1 year post-transplant. The HL-TAC group had significantly higher TAC trough levels at 2, 3, 4, and 5 years compared with the levels of the LL-TAC group. During the mean follow-up of 63.7 ± 13.0 months, there were 121 renal outcomes and 224 cardiovascular outcomes. In multivariate Cox regression analysis, LL-TAC and HL-TAC were not independent risk factors for renal and cardiovascular outcomes, respectively. No significant differences in the development of opportunistic infections and de novo donor-specific anti-human leukocyte antigen antibodies and renal allograft function were observed between the two groups.

Conclusions

TAC trough levels after 1 year post-transplant remained at a similar level until the fifth year after kidney transplantation and were not directly associated with long-term outcomes in stable Korean KTRs who did not experience renal or cardiovascular outcomes. Therefore, in Asian KTRs with a stable clinical course, TAC trough levels higher than approximately 6 ng/mL might not be required after a year of kidney transplantation.

Oxone®-Mediated TEMPO-Oxidized Cellulose Nanomaterial Ultrafiltration and Dialysis Mixed-Matrix Hollow Fiber Membranes

Recent exploration of cellulose nanomaterials has resulted in the creation of Oxone^®-Mediated TEMPO-Oxidized Cellulose Nanomaterials (OTO-CNMs). These materials, when incorporated into a polymer matrix, have properties showing increased flux, decreased membrane resistance, and improved clearance, making them an ideal material for dialysis. This study is the first to focus on the implementation of OTO-CNMs into hollow fiber membranes and a comparison of these membranes for ultrafiltration and dialysis. Ultrafiltration and dialysis were performed using bovine serum albumin (BSA), lysozyme, and urea to analyze various properties of each hollow fiber membrane type. The results presented in this study provide the first quantitative evaluation of the clearance and sieving characteristics of Oxone^®-Mediated TEMPO-Oxidized Cellulose-Nanomaterial-doped cellulose triacetate mixed-matrix hemodialyzers. While the cellulose nanomaterials increased flux (10–30%) in ultrafiltration mode, this was offset by increased removal of albumin. However, in dialysis mode, these materials drastically increased the mass transfer of components (50–100%), which could lead to significantly lower dialysis times for patients. This change in the performance between the two different modes is most likely due to the increased porosity of the cellulose nanomaterials.

Free Standing, Large-Area Silicon Nitride Membranes for High Toxin Clearance in Blood Surrogate for Small-Format Hemodialysis

Developing highly-efficient membranes for toxin clearance in small-format hemodialysis presents a fabrication challenge. The miniaturization of fluidics and controls has been the focus of current work on hemodialysis (HD) devices. This approach has not addressed the membrane efficiency needed for toxin clearance in small-format hemodialysis devices. Dr. Willem Kolff built the first dialyzer in 1943 and many changes have been made to HD technology since then. However, conventional HD still uses large instruments with bulky dialysis cartridges made of ~2 m2 of 10 micron thick, tortuous-path membrane material. Portable, wearable, and implantable HD systems may improve clinical outcomes for patients with end-stage renal disease by increasing the frequency of dialysis. The ability of ultrathin silicon-based sheet membranes to clear toxins is tested along with an analytical model predicting long-term multi-pass experiments from single-pass clearance experiments. Advanced fabrication methods are introduced that produce a new type of nanoporous silicon nitride sheet membrane that features the pore sizes needed for middle-weight toxin removal. Benchtop clearance results with sheet membranes (~3 cm2) match a theoretical model and indicate that sheet membranes can reduce (by orders of magnitude) the amount of membrane material required for hemodialysis. This provides the performance needed for small-format hemodialysis.

Fluid and hemodynamic management in hemodialysis patients: challenges and opportunities

Fluid volume and hemodynamic management in hemodialysis patients is an essential component of dialysis adequacy. Restoring salt and water homeostasis in hemodialysis patients has been a permanent quest by nephrologists summarized by the ‘dry weight’ probing approach. Although this clinical approach has been associated with benefits on cardiovascular outcome, it is now challenged by recent studies showing that intensity or aggressiveness to remove fluid during intermittent dialysis is associated with cardiovascular stress and potential organ damage. A more precise approach is required to improve cardiovascular outcome in this high-risk population. Fluid status assessment and monitoring rely on four components: clinical assessment, non-invasive instrumental tools (e.g., US, bioimpedance, blood volume monitoring), cardiac biomarkers (e.g. natriuretic peptides), and algorithm and sodium modeling to estimate mass transfer. Optimal management of fluid and sodium imbalance in dialysis patients consist in adjusting salt and fluid removal by dialysis (ultrafiltration, dialysate sodium) and by restricting salt intake and fluid gain between dialysis sessions. Modern technology using biosensors and feedback control tools embarked on dialysis machine, with sophisticated analytics will provide direct handling of sodium and water in a more precise and personalized way. It is envisaged in the near future that these tools will support physician decision making with high potential of improving cardiovascular outcome.

End-Stage Renal Disease Patients Lose a Substantial Amount of Amino Acids during Hemodialysis

BACKGROUND

Poor nutritional status is frequently observed in end-stage renal disease patients and associated with adverse clinical outcomes and increased mortality. Loss of amino acids (AAs) during hemodialysis (HD) may contribute to protein malnutrition in these patients.

OBJECTIVE

We aimed to assess the extent of AA loss during HD in end-stage renal disease patients consuming their habitual diet.

METHODS

Ten anuric chronic HD patients (mean ± SD age: 67.9 ± 19.3 y, BMI: 23.2 ± 3.5 kg/m2), undergoing HD 3 times per week, were selected to participate in this study. Spent dialysate was collected continuously and plasma samples were obtained directly before and after a single HD session in each participant. AA profiles in spent dialysate and in pre-HD and post-HD plasma were measured through ultra-performance liquid chromatography to determine AA concentrations and, as such, net loss of AAs. In addition, dietary intake before and throughout HD was assessed using a 24-h food recall questionnaire during HD. Paired-sample t tests were conducted to compare pre-HD and post-HD plasma AA concentrations.

RESULTS

During an HD session, 11.95 ± 0.69 g AAs were lost via the dialysate, of which 8.26 ± 0.46 g were nonessential AAs, 3.69 ± 0.31 g were essential AAs, and 1.64 ± 0.17 g were branched-chain AAs. As a consequence, plasma total and essential AA concentrations declined significantly from 2.88 ± 0.15 and 0.80 ± 0.05 mmol/L to 2.27 ± 0.11 and 0.66 ± 0.05 mmol/L, respectively (P < 0.05). AA profiles of pre-HD plasma and spent dialysate were similar. Moreover, AA concentrations in pre-HD plasma and spent dialysate were strongly correlated (Spearman's ρ = 0.92, P < 0.001).

CONCLUSIONS

During a single HD session, ∼12 g AAs are lost into the dialysate, causing a significant decline in plasma AA concentrations. AA loss during HD can contribute substantially to protein malnutrition in end-stage renal disease patients. This study was registered at the Netherlands Trial Registry (NTR7101).

Vascular Access and Risk of Bloodstream Infection Among Older Incident Hemodialysis Patients

Rationale & Objective

Most new patients with end-stage renal disease (ESRD) initiate hemodialysis (HD) with a central venous catheter (CVC) and later transition to a permanent vascular access with lower infection risk. The benefit of early fistula use in preventing severe infections is incompletely understood. We examined patients' first access and subsequent transitions between accesses during the first year of HD to estimate the risk for bloodstream infection (BSI) associated with incident and time-dependent use of HD access.

Study Design

A retrospective cohort study using enhanced 5% Medicare claims data.

Setting & Participants

New patients with ESRD initiating HD between January 1, 2011, and December 31, 2012, and having complete pre-ESRD Medicare fee-for-service coverage for 2 years.

Exposure

The incident and prevalent use of CVC, graft, or fistula as determined from monthly reports to the Centers for Medicare & Medicaid Services by HD providers.

Outcome

Incident hospitalization with a primary/secondary diagnosis of BSI (International Classification of Diseases, Ninth Revision, Clinical Modification code 038.xx or 790.7).

Analytical Approach

Extended survival analysis accounting for patient confounders.

Results

Of 2,352 study participants, 1,870 (79.5%), 77 (3.3%), and 405 (17.2%) initiated HD with a CVC, graft, and fistula, respectively. During the first year, the incident BSI hospitalization rates per 1,000 person-days were 1.3, 0.8, and 0.3 (P<0.001) in patients initiating with a CVC, graft, and fistula, respectively. After adjusting for confounders, incident fistula use was associated with 61% lower risk for BSI (HR, 0.39; 95% CI, 0.28-0.54; P<0.001) compared with incident CVC or graft use. The prevalent fistula or graft use was associated with lower risk for BSI compared with prevalent CVC use (HRs of 0.30 [95% CI, 0.22-0.42] and 0.47 [95% CI, 0.31-0.73], respectively).

Limitations

Restricted to an elderly population; potential residual confounding.

Conclusions

Incident fistula use was associated with lowest rates of BSI, but the majority of beneficiaries with pre-ESRD insurance initiated HD with a CVC. Strategies are needed to improve pre-ESRD fistula placement.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.

Molecular recognition of methamphetamine by carboxylatopillar[5]arene: drug-dependent complexation stoichiometry and insights into medical applications

The molecular recognition of the carboxylatopillar[5]arene on methamphetamine showed interconversion between H₂:G ⇋ H:G stoichiometries with dependence on drug concentration.

Cardiac arrest during hemodialysis: a survey of five Japanese hospitals

AIM

Intraprocedural cardiac arrest is a serious complication among patients receiving hemodialysis. However, the frequency and reaction to these events remain unclear. This study aimed to explore the clinical picture of cardiac arrest during hemodialysis.

METHODS

Ten cardiac arrests that had occurred during 217,984 hemodialysis treatments in five Japanese hospitals, between 2008 and 2017, were reviewed. We investigated the underlying disease, vital signs, emergency responses, and outcomes using patient medical records.

RESULTS

The cardiac arrest rate ranged from 1.1 to 7.5 per 100,000 hemodialysis sessions. All included cases of cardiac arrest occurred in a hemodialysis unit and had been witnessed and reported by supervising clinicians. The initial rhythm was ventricular fibrillation/ventricular tachycardia in six patients (60%) and pulseless electrical activity/asystole in four patients (40%). Seven (70%) patients showed a return of spontaneous circulation (ROSC), and two (20%) patients were discharged with a cerebral performance category score of 1. There was a statistically significant difference in the ROSC rate (P = 0.048) only in the event of an emergency call. The SpO2 and respiratory rates had not been recorded in six patients. There was no significant difference in ROSC between initial rhythms of ventricular fibrillation/ventricular tachycardia and pulseless electrical activity/asystole.

CONCLUSION

We evaluated the frequency of cardiac arrest during hemodialysis. Overall assessment including respiratory status is needed at initiation of hemodialysis. In case of a sudden change in a patient's status, high-quality resuscitation treatment that includes an emergency call can improve prognosis.

Dietary Protein and Physical Activity Interventions to Support Muscle Maintenance in End-Stage Renal Disease Patients on Hemodialysis

End-stage renal disease patients have insufficient renal clearance capacity left to adequately excrete metabolic waste products. Hemodialysis (HD) is often employed to partially replace renal clearance in these patients. However, skeletal muscle mass and strength start to decline at an accelerated rate after initiation of chronic HD therapy. An essential anabolic stimulus to allow muscle maintenance is dietary protein ingestion. Chronic HD patients generally fail to achieve recommended protein intake levels, in particular on dialysis days. Besides a low protein intake on dialysis days, the protein equivalent of a meal is extracted from the circulation during HD. Apart from protein ingestion, physical activity is essential to allow muscle maintenance. Unfortunately, most chronic HD patients have a sedentary lifestyle. Yet, physical activity and nutritional interventions to support muscle maintenance are generally not implemented in routine patient care. To support muscle maintenance in chronic HD patients, quantity and timing of protein intake should be optimized, in particular throughout dialysis days. Furthermore, implementing physical activity either during or between HD sessions may improve the muscle protein synthetic response to protein ingestion. A well-orchestrated combination of physical activity and nutritional interventions will be instrumental to preserve muscle mass in chronic HD patients.

A new biosensor detection system to overcome the Debye screening effect: dialysis-silicon nanowire field effect transistor

Background: A silicon nanowire field effect transistor biosensor has four advantages in the detection of small biomolecules. It is mark-free, immediately responsive, highly sensitive, and specific. However, because of environments with a high salt concentration, the Debye screening effect has been a major issue in biological detection. Objective: To overcome Debye screening effect, realize the clinical application of silicon nanowire field effect transistor and verify its specificity and sensitivity. Materials and methods: The test solution was desalted by miniature blood dialyzer, and then the tumor markers were detected by silicon nanowire field effect transistor. Results: Tumor markers in serum were detected successfully and their sensitivity and specificity were verified. Conclusion: This method was found to effectively promote the development of semiconductor materials in biological solution detection.

Assessment of nutritional status in the maintenance of haemodialysis patients: a cross-sectional study from Palestine

BACKGROUND

Protein-energy wasting (PEW) is a relatively prevalent problem among adult haemodialysis patients (HDP). PEW is an important determinant of morbidity and mortality in HDP, therefore it is essential for dietitians to accurately assess malnutrition (MN) in these patients. HDP appear to be more susceptible to developing MN; however, this is not well documented. Therefore this study aimed to assess the nutritional status among HDP and to establish the factors associated with MN in these patients.

METHODS

A cross-sectional survey was carried out in Nablus, northern West Bank, in the main haemodialysis (HD) centre at the An-Najah National University Hospital. MN was detected using the malnutrition-inflammation scale (MIS), which involved four major elements: the patient's related medical history, their body mass index, a physical examination and laboratory parameters.

RESULTS

A total of 174 patients (91 male) were included in the study. Patients were aged 57.7 ± 12.8 years, and the median dialysis vintage was 3 years (interquartile range 1-5 years). HDP, especially the elderly (unstandardized coefficient β, 1.728; 95% CI, 0.700 to 2.756; P = 0.001), those with multiple comorbid diseases (unstandardized coefficient β, 1.673; 95% CI, 0.556 to 2.789; P = 0.004); those taking multiple chronic medications (unstandardized coefficient β, 1.259; 95% CI, 0.197 to 2.321; P = 0.020), or those with a long dialysis vintage (unstandardized coefficient β, 1.449; 95% CI, 0.410 to 2.487; P = 0.007), were positively associated with the MIS score in a multivariable linear regression model. Furthermore, HDP living with their family were negatively associated with the MIS score (unstandardized coefficient β, - 2.545; 95% CI, - 4.738 to - 0.352; P = 0.023).

CONCLUSIONS

The MIS score results indicate that MN is prevalent among HDP. These results demonstrate some correlations between nutritional status and patient characteristics (i.e. clinical and sociodemographic factors). Therefore these findings should help to increase the awareness of healthcare providers for interventions to enhance the nutritional status of HDP, especially those who are elderly, have multiple comorbid diseases, have multiple chronic medications, have experienced a long dialysis vintage or who live alone.

Global prevalent use, trends and practices in haemodiafiltration

Online haemodiafiltration (HDF) represents today the most advanced and innovative form of renal replacement therapy (RRT). Recent controlled trials tend to prove its superiority over conventional haemodialysis on hard clinical end points provided that the right convective dose was delivered. In this article we report on present prevalent use and epidemiologic trends of HDF worldwide as well as on practice patterns in HDF prescription. In addition we analyze factors that may affect HDF clinical acceptance and more widely its implementation. National and international renal registries provide valuable demographic and epidemiologic information on end stage kidney disease patients on RRT. However, the updating and maintenance of such information system is particularly challenging at a country level and even more so on an international basis. Lag time, incompleteness and/or imprecision of data collection may further hamper precision and validity of data reporting. Fresenius Medical Care (FMC), as a large dialysis care provider operating worldwide, maintains an annually updated database addressing international end stage kidney disease data. Over the last decade, FMC has produced series of precise and reliable reports analyzing RRT trends and practices worldwide. The present overview and analysis is based on our consolidated data from market survey as well as national database registries and databases of recent studies. Online HDF acceptance is growing fast in the two leading regions having approved the method, i.e. Europe and Asia Pacific, with a patient average growth rate of 12 to 24%, being far above the total patient HD growth rate of 6.6%. Today online HDF represents a new paradigm shift in RRT with promising clinical results. Further initiatives (e.g., Kidney Health Initiative, NICE) might provide further push for promoting HDF as a new standard of care in end stage kidney disease patients on a global scale.

Microbiome-metabolome reveals the contribution of gut-kidney axis on kidney disease

Dysbiosis represents changes in composition and structure of the gut microbiome community (microbiome), which may dictate the physiological phenotype (health or disease). Recent technological advances and efforts in metagenomic and metabolomic analyses have led to a dramatical growth in our understanding of microbiome, but still, the mechanisms underlying gut microbiome-host interactions in healthy or diseased state remain elusive and their elucidation is in infancy. Disruption of the normal gut microbiota may lead to intestinal dysbiosis, intestinal barrier dysfunction, and bacterial translocation. Excessive uremic toxins are produced as a result of gut microbiota alteration, including indoxyl sulphate, p-cresyl sulphate, and trimethylamine-N-oxide, all implicated in the variant processes of kidney diseases development. This review focuses on the pathogenic association between gut microbiota and kidney diseases (the gut-kidney axis), covering CKD, IgA nephropathy, nephrolithiasis, hypertension, acute kidney injury, hemodialysis and peritoneal dialysis in clinic. Targeted interventions including probiotic, prebiotic and symbiotic measures are discussed for their potential of re-establishing symbiosis, and more effective strategies for the treatment of kidney diseases patients are suggested. The novel insights into the dysbiosis of the gut microbiota in kidney diseases are helpful to develop novel therapeutic strategies for preventing or attenuating kidney diseases and complications.

The state of nutrition care in outpatient hemodialysis settings in Malaysia: a nationwide survey

BACKGROUND

This study aimed to assess the situational capacity for nutrition care delivery in the outpatient hemodialysis (HD) setting in Malaysia by evaluating dietitian accessibility, nutrition practices and patients' outcomes.

METHODS

A 17-item questionnaire was developed to assess nutrition practices and administered to dialysis managers of 150 HD centers, identified through the National Renal Registry. Nutritional outcomes of 4362 patients enabled crosscutting comparisons as per dietitian accessibility and center sector.

RESULTS

Dedicated dietitian (18%) and visiting/shared dietitian (14.7%) service availability was limited, with greatest accessibility at government centers (82.4%) > non-governmental organization (NGO) centers (26.7%) > private centers (15.1%). Nutritional monitoring varied across HD centers as per albumin (100%) > normalized protein catabolic rate (32.7%) > body mass index (BMI, 30.7%) > dietary intake (6.0%). Both sector and dietitian accessibility was not associated with achieving albumin ≥40 g/L. However, NGO centers were 36% more likely (p = 0.030) to achieve pre-dialysis serum creatinine ≥884 μmol/L compared to government centers, whilst centers with dedicated dietitian service were 29% less likely (p = 0.017) to achieve pre-dialysis serum creatinine ≥884 μmol/L. In terms of BMI, private centers were 32% more likely (p = 0.022) to achieve BMI ≥ 25.0 kg/m² compared to government centers. Private centers were 62% less likely (p <  0.001) while NGO centers were 56% less likely (p <  0.001) to achieve serum phosphorus control compared to government centers. Patients from centers with a shared/visiting dietitian had 35% lower probability (p <  0.001) to achieve serum phosphorus levels below 1.78 mmol/L compared to centers without access to a dietitian.

CONCLUSIONS

There were clear discrepancies in nutritional care in Malaysian HD centers. Changes in stakeholder policy are required to ensure that dietitian service is available in Malaysian HD centers.

Efficacy of different hemodialysis methods on dendritic cell marker CD40 and CD80 and platelet activation marker CD62P and P10 in patients with chronic renal failure

BACKGROUND

Chronic renal failure (CRF) has become a major public health concern, which increases the risk of stroke and systemic thromboembolism. Therefore, therapeutic strategies are in urgent requirement. This study was conducted for investigating efficacy of hemodialysis (HD), hemodiafiltration (HDF), and hemoperfusion (HP) in patients with CRF and the correlation with the presence of complications following HD therapy.

METHODS

The therapeutic effect, living quality, biochemical indicators, and dry weight were detected before and after the treatment regimens. Flow cytometry was conducted to detect expressions of dendritic cell markers (CD40 and CD80) and platelet activation markers (CD62P and P10), and the relationship between their expression and therapeutic effect as well as the association of these expressions with complications was analyzed.

RESULTS

After HD therapy, patients presented with decreased serum creatinine, serum phosphorus, triglyceride, parathyroid hormone, and β₂ -MG expression; increased hemoglobin, plasma albumin expressions, and dry weight; and enhanced therapeutic effect and living quality. CD62P and P10 expressions decreased, while CD40 and CD80 expressions increased following HD therapy. The therapeutic effect improved in patients with low expressions of CD40 and CD80 and high expressions of CD62P and P10 following HP treatment and complications were lower after treatment of HDF and HP.

CONCLUSION

The aforementioned results indicated that CRF patients treated with HP exhibited higher expression of CD40 and CD80 and lower expression of CD62P and P10, suggesting that HP is conferred to have better efficacy than HDF and HD. Therefore, HP may be a promising clinical regimen for treatment of CRF patients.

Influence of ultrasound on the clearance of toxic substances from Polysulfone hollow fiber membrane used in a dialyzer filter

The aim of this work was to investigate the potential of high frequency ultrasound for the cleaning of a Polysulfone (PSU) ultrafiltration membrane used in hemodialysis. The blood substitute solution flowing through the hollow fiber membrane used in the High Flux F60 dialyzers has been sonicated by ultrasonic (US) waves with 1 MHz frequency and 2 W/cm2 in situ intensity. The solution was comprised of toxic compounds such as Urea, Creatinine, Vitamin B12 and Inulin. The effect of US was represented by comparison of the clearance in both OFF and ON ultrasound conditions. The results of these studies have been demonstrated that US can enhance the permeability of the PSU dialyzer membrane. Results revealed that US had significant effect (p-value ˂ 0.05) on the clearance of Inulin as a large molecule (5200 D) and accelerated its filtration by 28%. The proposed dialysis method can be used alongside the existing dialysis machine.

Factors That Condition the Attitude Toward Living Related Kidney Donation Among Santiago of Cuba's Population

INTRODUCTION

Living kidney donation is currently the most important kidney donor source in Latin America, and it is necessary to further increase its rates.

OBJECTIVE

To analyze the attitude toward living kidney donation among the Santiago de Cuba's population and to determine the sociopersonal factors with which it is associated.

METHOD

The population over 15 years old residing in Santiago de Cuba, stratified by sex and age, was screened. The "PCID-LKD Ríos" attitude questionnaire toward living kidney donation was administered to a random selection of the people surveyed according to the stratification and the census data. The completion was anonymized and self-administered. Verbal consent was obtained.

RESULTS

The study was completed by 445 people, of whom the 86% (n = 389) were in favor of living related kidney donation. This attitude is associated with the level of education (P < .001); previous experience with organ donation (P = .006); attitude toward cadaveric organ donation (P < .001); carrying out of prosocial activities (P = .010); discussion of the issue with the family (P < .001) and the significant other (P < .001); concern about mutilation after donation (P = .001); religious beliefs (P = .001); and assessment of the risk of living kidney donation (P < .001). In the multivariate study, the following variables persisted: (1) level of education; (2) attitude of cadaveric donation; (3) carrying out of prosocial activities; and (4) risk assessment of living donation.

CONCLUSIONS

Living related donation is very well accepted among the Santiago de Cuba's population.

Psychiatric comorbidity in patients undergoing hemodialysis

BACKGROUND

Patients undergoing hemodialysis are under considerable physical and mental stress. Few studies indicate an increase of psychiatric morbidity in them.

AIM

The aim is to study the prevalence of psychiatric comorbidity in patients undergoing hemodialysis.

MATERIALS AND METHODS

A total of 49 consecutive patients of chronic kidney disease undergoing hemodialysis were included in the study with their consent. The Institute Ethics Committee clearance was obtained before the start of the study. The psychiatric interview was conducted only after the dialysis procedure was over. Patients were assessed using the Schedule for Clinical Assessment in Neuropsychiatry and Hamilton rating scale for depression.

RESULTS

A total of 49 patients in the age range of 15-64 years were included in the study. Majority of the sample was males (75.5%). Out of the patients enrolled in the study group, 45% had psychiatric comorbidity which included depression (26%), adjustment disorder (12.2%), generalized anxiety disorder (2%), mixed anxiety and depression (2%), and mental and behavioral disorders due to harmful use of alcohol (2%) indicating that patients undergoing hemodialysis is more likely to have mood disorder than other psychiatric disorders.

CONCLUSION

Patients with recent-onset dialysis are more prone to psychiatric illnesses as it has a chronic debilitating course with poor outcome leading to major lifestyle changes with occupational disturbance and consequent financial implication.

Usefulness of the KDPI in Spain: A comparison with donor age and definition of standard/expanded criteria donor

INTRODUCTION

Kidney donor shortage requires expanding donor selection criteria, as well as use of objective tools to minimize the percentage of discarded organs. Some donor pre-transplant variables such as age, standard/expanded criteria donor (SCD/ECD) definition and calculation of the Kidney Donor Profile Index (KDPI), have demonstrated correlations with patient and graft outcomes. We aimed to establish the accuracy of the three models to determine the prognostic value of kidney transplantation (KT) major outcomes.

MATERIAL AND METHODS

We performed a retrospective study in deceased donor KTs at our institution. Unadjusted Cox and Kaplan-Meier survival, and multivariate Cox analyses were fitted to analyze the impact of donor age, SCD/ECD and KDPI on outcomes.

RESULTS

389 KTs were included. Mean donor age was 53.6±15.2 years; 163 (41.9%) came from ECD; mean KDPI was 69.4±23.4%. Median follow-up was 51.9 months. The unadjusted Cox and Kaplan-Meier showed that the three prognostic variables of interest were related to increased risk of patient death, graft failure and death-censored graft failure. However, in the multivariate analysis only KDPI was related to a higher risk of graft failure (HR 1.03 [95% CI 1.01-1.05]; p=0.014).

CONCLUSIONS

SCD/ECD classification did not provide significant prognostic information about patient and graft outcomes. KDPI was linearly related to a higher risk of graft failure, providing a better assessment. More studies are needed before using KDPI as a tool to discard or accept kidneys for transplantation.

Factors influencing dialysis withdrawal: a scoping review

BACKGROUND

Research on factors associated with dialysis withdrawal is scarce. This study examined the predictors that might influence rate of dialysis withdrawal. Existing literature is summarized, analyzed and synthesized to identify gaps in the literature with regard to the factors associated with dialysis withdrawal.

METHODS

This scoping review used a systematic search to synthesize research findings related to dialysis withdrawal and identified gaps in the literature. The search strategy was developed and applied using PubMed, EMBASE and CINHAL databases. The selection criteria included articles written in English and published between 1997 and 2016 that examined dialysis withdrawal and associated factors in patients with any modality of renal dialysis.. Case reports and studies only including renal transplant patients were excluded. Fifteen articles were selected in accordance with these selection criteria.

RESULTS

The literature review revealed a scarcity of research on dialysis withdrawal and associated factors. Furthermore, the study findings were inconsistent and inconclusive. Authors have defined dialysis withdrawal in terms of dialysis discontinuation, withholding, death, withdrawal, treatment refusal/cessation, or technique failure. Authors have selected homogeneous patient population on either hemodialysis (HD) or peritoneal dialysis (PD) patients, thus making comparisons of studies and generalization of findings difficult.

CONCLUSION

Future studies should explore the influence of both HD and PD on patient-elected dialysis withdrawal using a large a priori calculated sample size.

Mathematical model of calcium exchange during haemodialysis using a citrate containing dialysate

Calcium has two important roles in haemodialysis. It participates in the activation of blood coagulation and calcium intakes have a major impact on patient mineral and bone metabolism. The aim of this article is to propose a mathematical model for calcium ions concentration in a dialyzer during haemodialysis using a citrate dialysate. The model is composed of two elements. The first describes the flows of blood and dialysate in a dialyzer fibre. It was obtained by asymptotic analysis and takes into account the anisotropy of the fibres forming a dialyzer. Newtonian and non-Newtonian blood rheologies were tested. The second part of the model predicts the evolution of the concentration of five chemical species present in these fluids. The fluid velocity field drives the convective part of a convection-reaction-diffusion system that models the exchange of free and complexed calcium. We performed several numerical experiments to calculate the free calcium concentration in the blood in a dialyzer using dialysates with or without citrate. The choice of blood rheology had little effect on the fluid velocity field. Our model predicts that only a citrate based dialysate without calcium can decrease free calcium concentration at the blood membrane interface low enough to inhibit blood coagulation. Moreover for a given calcium dialysate concentration, adding citrate to the dialysate decreases total calcium concentration in the blood at the dialyzer outlet. This decrease of the calcium concentration can be compensated by infusing in the dialyzed blood a quantity of calcium computed from the model.

Extended Duration Nocturnal Hemodialysis and Changes in Plasma Metabolite Profiles

BACKGROUND AND OBJECTIVES

In-center, extended duration nocturnal hemodialysis has been associated with variable clinical benefits, but the effect of extended duration hemodialysis on many established uremic solutes and other components of the metabolome is unknown. We determined the magnitude of change in metabolite profiles for patients on extended duration nocturnal hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a 52-week prospective, observational study, we followed 33 patients receiving conventional thrice weekly hemodialysis who converted to nocturnal hemodialysis (7-8 hours per session, three times per week). A separate group of 20 patients who remained on conventional hemodialysis (3-4 hours per session, three times per week) served as a control group. For both groups, we applied liquid chromatography-mass spectrometry-based metabolite profiling on stored plasma samples collected from all participants at baseline and after 1 year. We examined longitudinal changes in 164 metabolites among those who remained on conventional hemodialysis and those who converted to nocturnal hemodialysis using Wilcoxon rank sum tests adjusted for multiple comparisons (false discovery rate <0.05).

RESULTS

On average, the nocturnal group had 9.6 hours more dialysis per week than the conventional group. Among 164 metabolites, none changed significantly from baseline to study end in the conventional group. Twenty-nine metabolites changed in the nocturnal group, 21 of which increased from baseline to study end (including all branched-chain amino acids). Eight metabolites decreased after conversion to nocturnal dialysis, including l-carnitine and acetylcarnitine. By contrast, several established uremic retention solutes, including p-cresol sulfate, indoxyl sulfate, and trimethylamine N-oxide, did not change with extended dialysis.

CONCLUSIONS

Across a wide array of metabolites examined, extended duration hemodialysis was associated with modest changes in the plasma metabolome, with most differences relating to metabolite increases, despite increased dialysis time. Few metabolites showed reduction with more dialysis, and no change in several established uremic toxins was observed.

Clinical and hematological data to group different chronic kidney disease patients: A practical approach to establish different groups of patients

BACKGROUND

Chronic kidney disease (CKD) is the convergent point of several pathological processes, and its evolution is insidious and characterized by a progressive and irreversible loss of kidney function. This impaired function induces the accumulation of uremic toxins and individuals with terminal CKD often have altered physiological responses, including a persistent state of immuno-suppression and development of diseases. A better characterization and stratification of these patients with CKD in different immuno-compromised groups would contribute to more effective and personalized treatments. The focus of this study was to use two parameters to stratify patients with CKD into four separate groups that are representative of different immunological status.

METHODS

Patients with CKD were chosen randomly and stratified into four separate groups according to the period of time receiving dialysis treatment and leukocyte blood counts. The amount of apoptotic CD4 T cells were measured in each group of patients, and clinical/hematological parameters were correlated by multivariate analysis with each group.

RESULTS

Observations reveal that one of the four groups of patients with CKD (group 3) had more apoptotic CD4 T cells than the other group; this group also had an increased malnutrition inflammation score (MIS), an elevated Kt/V, and a higher incidence of smoking.

CONCLUSION

A simple two-parameter-based stratification strategy could be used to design effective immunological therapies that differentiate the degrees of immuno-suppression across groups of patients with CKD.

Impact of Altered Mineral Metabolism on Pathological Cardiac Remodeling in Elevated Fibroblast Growth Factor 23

Clinical and experimental studies indicate a possible link between high serum levels of fibroblast growth factor 23 (FGF23), phosphate, and parathyroid hormone (PTH), deficiency of active vitamin D (1,25D) and klotho with the development of pathological cardiac remodeling, i.e., left ventricular hypertrophy and myocardial fibrosis, but a causal link has not been established so far. Here, we investigated the cardiac phenotype in klotho hypomorphic (kl/kl) mice and Hyp mice, two mouse models of elevated FGF23 levels and klotho deficiency, but differing in parameters of mineral metabolism, by using histology, quantitative real-time PCR, immunoblot analysis, and serum and urine biochemistry. Additionally, the specific impact of calcium, phosphate, PTH, and 1,25D on hypertrophic growth of isolated neonatal rat cardiac myocytes was investigated in vitro. Kl/kl mice displayed high serum Fgf23 levels, increased relative heart weight, enhanced cross-sectional area of individual cardiac myocytes, activated cardiac Fgf23/Fgf receptor (Fgfr) 4/calcineurin/nuclear factor of activated T cell (NFAT) signaling, and induction of pro-hypertrophic NFAT target genes including Rcan1, bMHC, brain natriuretic peptide (BNP), and atrial natriuretic peptide (ANP) as compared to corresponding wild-type (WT) mice. Investigation of fibrosis-related molecules characteristic for pathological cardiac remodeling processes demonstrated ERK1/2 activation and enhanced expression of Tgf-β1, collagen I, and Mmp2 in kl/kl mice than in WT mice. In contrast, despite significantly elevation of serum and cardiac Fgf23, and reduced renal klotho expression, Hyp mice showed no signs of pathological cardiac remodeling. Kl/kl mice showed enhanced serum calcium and phosphate levels, while Hyp mice showed unchanged serum calcium levels, lower serum phosphate, and elevated serum iPTH concentrations compared to corresponding WT mice. In cultured cardiac myocytes, treatment with both calcium or phosphate significantly upregulated endogenous Fgf23 mRNA expression and stimulated hypertrophic cell growth and expression of pro-hypertrophic genes. The treatment with PTH induced hypertrophic cell growth only, and stimulation with 1,25D had no significant effects. In conclusion, our data indicate that Hyp mice, in contrast to kl/kl mice appear to be protected from pathological cardiac remodeling during conditions of high FGF23 levels and klotho deficiency, which may be due, at least in part, to differences in mineral metabolism alterations, i.e., hypophosphatemia and lack of hypercalcemia.

Paracrine Effects of FGF23 on the Heart

Fibroblast growth factor (FGF) 23 is a phosphaturic hormone primarily secreted by osteocytes to maintain phosphate and mineral homeostasis. In patients with and without chronic kidney disease, enhanced circulating FGF23 levels associate with pathologic cardiac remodeling, i.e., left ventricular hypertrophy (LVH) and myocardial fibrosis and increased cardiovascular mortality. Experimental studies demonstrate that FGF23 promotes hypertrophic growth of cardiac myocytes via FGF receptor 4-dependent activation of phospholipase Cγ/calcineurin/nuclear factor of activated T cell signaling independent of its co-receptor klotho. Recent studies indicate that FGF23 is also expressed in the heart, and markedly enhanced in various clinical and experimental settings of cardiac remodeling and heart failure independent of preserved or reduced renal function. On a cellular level, FGF23 is expressed in cardiac myocytes and in other non-cardiac myocytes, including cardiac fibroblasts, vascular smooth muscle and endothelial cells in coronary arteries, and in inflammatory macrophages. Current data suggest that secreted by cardiac myocytes, FGF23 can stimulate pro-fibrotic factors in myocytes to induce fibrosis-related pathways in fibroblasts and consequently cardiac fibrosis in a paracrine manner. While acting on cardiac myocytes, FGF23 directly induces pro-hypertrophic genes and promotes the progression of LVH in an autocrine and paracrine fashion. Thus, enhanced FGF23 may promote cardiac injury in various clinical settings not only by endocrine but also via paracrine/autocrine mechanisms. In this review, we discuss recent clinical and experimental data regarding molecular mechanisms of FGF23's paracrine action on the heart with respect to pathological cardiac remodeling.

Examining hemodialyzer membrane performance using proteomic technologies

The success and the quality of hemodialysis therapy are mainly related to both clearance and biocompatibility properties of the artificial membrane packed in the hemodialyzer. Performance of a membrane is strongly influenced by its interaction with the plasma protein repertoire during the extracorporeal procedure. Recognition that a number of medium-high molecular weight solutes, including proteins and protein-bound molecules, are potentially toxic has prompted the development of more permeable membranes. Such membrane engineering, however, may cause loss of vital proteins, with membrane removal being nonspecific. In addition, plasma proteins can be adsorbed onto the membrane surface upon blood contact during dialysis. Adsorption can contribute to the removal of toxic compounds and governs the biocompatibility of a membrane, since surface-adsorbed proteins may trigger a variety of biologic blood pathways with pathophysiologic consequences. Over the last years, use of proteomic approaches has allowed polypeptide spectrum involved in the process of hemodialysis, a key issue previously hampered by lack of suitable technology, to be assessed in an unbiased manner and in its full complexity. Proteomics has been successfully applied to identify and quantify proteins in complex mixtures such as dialysis outflow fluid and fluid desorbed from dialysis membrane containing adsorbed proteins. The identified proteins can also be characterized by their involvement in metabolic and signaling pathways, molecular networks, and biologic processes through application of bioinformatics tools. Proteomics may thus provide an actual functional definition as to the effect of a membrane material on plasma proteins during hemodialysis. Here, we review the results of proteomic studies on the performance of hemodialysis membranes, as evaluated in terms of solute removal efficiency and blood-membrane interactions. The evidence collected indicates that the information provided by proteomic investigations yields improved molecular and functional knowledge and may lead to the development of more efficient membranes for the potential benefit of the patient.

[Development of methods to evaluate nephrological screening and support measures, and lessons learned from the Styrian nephrological screening program "niere.schützen"]

Throughout the world, the incidence and prevalence of patients with chronic kidney disease have been steadily rising. In 2016, the Styrian nephrology awareness program "niere.schützen" ("Kidney Protection") was launched to early identify patients with renal insufficiency. The aim of this study was to search for existing international nephrological screening and support programs in order to identify possible evaluation parameters and concepts for niere.schützen. A search in MEDLINE® revealed five relevant international programs from four countries. These differed from one another with respect to the population to be screened, the screening method and the support measures. All the programs involved the transparent documentation of patient data, and allowed for disease monitoring, as well as the impact of specific measures on assessed parameters and variables (laboratory data, participation rates) to be determined. Depending on the data sources employed and the availability and comprehensiveness of additional documentation, three evaluation methods of different informative value were developed. The first method requires no participant labelling, while the second and third methods require the participants to be assigned to a particular program. With the third method, the documentation also needs to be conducted in line with a disease management program. Considering that the speedy implementation of the niere.schützen program is desired for political reasons, the only practical method is the first one as it does not entail patient documentation and only involves the evaluation of process parameters.

The Perceived Medical Condition Self-Management Scale can be applied to patients with chronic kidney disease

Chronic Kidney Disease (CKD) is a major burden on patients and the health care system. Treatment of CKD requires dedicated involvement from both caretakers and patients. Self-efficacy, also known as perceived competence, contributes to successful maintenance of patient's CKD self-management behaviors such as medication adherence and dietary regulations. Despite a clear association between self-efficacy and improved CKD outcomes, there remains a lack of validated self-report measures of CKD self-efficacy. To address this gap, the Perceived Kidney/Dialysis Self-Management Scale (PKDSMS) was adapted from the previously validated Perceived Medical Condition Self-Management Scale. We then sought to validate this using data from two separate cohorts: a cross-sectional investigation of 146 patients with end-stage renal disease receiving maintenance hemodialysis and a longitudinal study of 237 patients with CKD not receiving dialysis. The PKDSMS was found to be positively and significantly correlated with self-management behaviors and medication adherence in both patient cohorts. The PKDSMS had acceptable reliability, was internally consistent, and exhibited predictive validity between baseline PKDSMS scores and self-management behaviors across multiple time points. Thus, the PKDSMS is a valid and reliable measure of CKD patient self-efficacy and supports the development of interventions enhancing perceived competence to improve CKD self-management.