Association between dementia diagnosis at dialysis initiation and mortality in older patients with end-stage kidney disease in South Korea

Background

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis.

Methods

We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort.

Results

Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization.

Conclusion

A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Role of the CCL20/CCR6 axis in tubular epithelial cell injury: Kidney-specific translational insights from acute kidney injury to chronic kidney disease

This study investigated the role of the axis involving chemokine receptor 6 (CCR6) and its ligand chemokine (C-C motif) ligand 20 (CCL20) in acute kidney disease (AKD) using an ischemia-reperfusion injury (IRI) model. The model was established by clamping the unilateral renal artery pedicle of C57BL/6 mice for 30 min, followed by evaluation of CCL20/CCR6 expression at 4 weeks post-IRI. In vitro studies were conducted to examine the effects of hypoxia and H2 O2 -induced oxidative stress on CCL20/CCR6 expression in kidney tissues of patients with AKD and chronic kidney disease (CKD). Tubular epithelial cell apoptosis was more severe in C57BL/6 mice than in CCL20 antibody-treated mice, and CCR6, NGAL mRNA, and IL-8 levels were higher under hypoxic conditions. CCL20 blockade ameliorated apoptotic damage in a dose-dependent manner under hypoxia and reactive oxygen species injury. CCR6 expression in IRI mice indicated that the disease severity was similar to that in patients with the AKD phenotype. Morphometry of CCL20/CCR6 expression revealed a higher likelihood of CCR6+ cell presence in CKD stage 3 patients than in stage 1-2 patients. Kidney tissues of patients with CKD frequently contained CCL20+ cells, which were positively correlated with interstitial inflammation. CCL20/CCR6 levels were increased in fibrotic kidneys at 4 and 8 weeks after 5/6 nephrectomy. These findings suggest that modulating the CCL20/CCR6 pathway is a potential therapeutic strategy for managing the progression of AKD to CKD.

Importance of dialysis specialists in early mortality in elderly hemodialysis patients: a multicenter retrospective cohort study

The early mortality rate in elderly patients undergoing hemodialysis is more than twice that in young patients, requiring more specialized healthcare. We investigated whether the number of professional dialysis specialists affected early mortality in elderly patients undergoing hemodialysis. This multicenter retrospective cohort study analyzed data from 1860 patients aged ≥ 70 years who started hemodialysis between January 2010 and December 2017. Study regions included Seoul, Gyeonggi-do, Gangwon-do, Daejeon/Chungcheong-do, Daegu/Gyeongsangbuk-do, and Busan/Ulsan/Gyeongsangnam-do. The number of patients undergoing hemodialysis per dialysis specialist was calculated using registered data from each hemodialysis center. Early mortality was defined as death within 6 months of hemodialysis initiation. Gangwon-do (28.3%) and Seoul (14.5%) showed the highest and lowest early mortality rate, respectively. Similarly, Gangwon-do (64.6) and Seoul (43.9) had the highest and lowest number of patients per dialysis specialist, respectively. Relatively consistent results were observed for the regional rankings of early mortality rate and number of patients per dialysis specialist. Multivariate Cox regression analysis-adjusted for previously known significant risk factors-revealed that the number of patients per dialysis specialist was an independent risk factor for early mortality (hazard ratio: 1.031, p < 0.001). This study underscores the growing need for dialysis specialists for elderly hemodialysis patients in Korea.

Effect of low-density lipoprotein level and mortality in older incident statin-naïve hemodialysis patients

BACKGROUND

This study aimed to analyze low-density lipoprotein cholesterol (LDL-C) levels and their relationship with mortality in order to identify the appropriate lipid profile for older Korean hemodialysis patients.

METHODS

We enrolled a total of 2,732 incident hemodialysis patients aged > 70 years from a retrospective cohort of the Korean Society of Geriatric Nephrology from 2010 Jan to 2017 Dec, which included 17 academic hospitals in South Korea. Of these patients, 1,709 were statin-naïve, and 1,014 were analyzed after excluding those with missing LDL-C level data. We used multivariate Cox regression analysis to select risk factors from 20 clinical variables among the LDL-C groups.

RESULTS

The mean age of the entire patient population was 78 years, with no significant differences in age between quartiles Q1 to Q4. However, the proportion of males decreased as the quartiles progressed towards Q4 (p < 0.001). The multivariate Cox regression analysis, which included all participants, showed that low LDL-C levels were associated with all-cause mortality. In the final model, compared to Q1, the hazard ratios (95% confidence interval) were 0.77 (0.620-0.972; p = 0.027), 0.85 (0.676-1.069; p = 0.166), and 0.65 (0.519-0.824; p < 0.001) for Q2, Q3, and Q4, respectively, after adjusting for covariates, such as conventional and age-specific risk factors. The final model demonstrated that all-cause mortality increased as LDL-C levels decreased, as confirmed by a restrictive cubic spline plot.

CONCLUSIONS

In older hemodialysis patients who had not previously received dyslipidemia treatment, elevated LDL-C levels were not associated with increased all-cause mortality. Intriguingly, lower LDL-C levels appear to be associated with an unfavorable effect on all-cause mortality among high-risk hemodialysis patients.

Association between food insecurity and risk of chronic diseases affecting the kidney in older Korean patients

AIMS

This study aimed to examine the association between food insecurity and the prevalence of chronic diseases among older adults in South Korea and to compare the findings with data from the United States (US).

MATERIALS AND METHODS

We analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010 - 2012) and VI (2013 - 2015) and 4 years (2012 - 2015) of food security questionnaire data. The data of 46,189 National Health and Nutrition Examination Survey participants (1999 - 2016) were subjected to propensity score-matched (PSM) analysis.

RESULTS

We included 7,914 individuals from the KNHANES. In the older group (age > 65 years), no differences were observed in the prevalence of hypertension, diabetes, chronic kidney disease (CKD), and metabolic syndrome across the income groups. Income, education, and food security had no impact on hypertension, diabetes, and CKD prevalence in the multivariate logistic analysis after PSM. CKD was not associated with food insecurity (odds ratio (OR), 1.26; 95% confidence interval (CI), 0.94 - 1.26) in the final model using the KNHANES data; however, the U.S. NHANES data showed that an increased risk of hypertension was associated with food insecurity (OR, 1.27; 95% CI, 1.04 - 1.55).

CONCLUSION

As per the U.S. NHANES data, food insecurity was associated with a high prevalence of hypertension, while as per the South Korean KNHANES data, food insecurity was not found to be associated with CKD, indicating divergent relationships between food insecurity and chronic diseases in the two countries. Further research is needed to explore these differences.

Metformin Use and Long-term Clinical Outcomes in Kidney Transplant Recipients

RATIONALE & OBJECTIVE

Metformin has been recommended for some patients with advanced chronic kidney disease. However, the value of metformin in kidney transplant recipients (KTRs) with pretransplant diabetes mellitus (DM) or posttransplant DM is uncertain. We investigated the clinical effects of metformin in KTRs.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A total of 1,995 KTRs with diabetes from 6 tertiary referral centers in the Republic of Korea.

EXPOSURE

Metformin usage was defined as the use of metformin for>90 days after kidney transplantation; 1,193 KTRs were metformin users, and 802 KTRs did not use metformin. Changing usage of metformin among those exposed for >90 days was also characterized.

OUTCOME

Primary outcomes were all-cause mortality and death-censored graft failure (DCGF). Secondary outcomes were biopsy-proven acute rejection (BPAR) and lactic acidosis events.

ANALYTICAL APPROACH

Survival analyses were conducted using multivariable Cox regression and competing risk analyses using Fine and Gray models. Changes in metformin use over time were modeled using a time-varying covariate. Metformin usage, mean daily dose, and hemoglobin A1c (HbA1c) changes were considered in the landmark analysis to address time-varying confounding.

RESULTS

Metformin use was associated with a lower risk of DCGF (adjusted hazard ratio [AHR], 0.47 [95% CI, 0.23-0.96], P=0.038); there was no significant association with all-cause mortality (AHR, 0.94 [95% CI, 0.32-2.76], P=0.915) or BPAR (AHR 0.98 [95% CI, 0.62-1.54], P=0.942). In the subgroup analysis, metformin usage was associated with a reduced risk of all-cause mortality and a lower risk of DCGF for both pretransplantation DM and posttransplant DM groups. Metformin usage was associated with a lower risk of BPAR in the posttransplant DM group, although it was less effective in the pretransplantation DM group. There was no confirmed case of metformin-associated lactic acidosis (MALA) in the present cohort. A higher dose of metformin was correlated with lower risks of DCGF and BPAR.

LIMITATIONS

Data on newer antidiabetic drugs such as SGLT2 inhibitors are limited, and there is potential limited generalizability to other populations.

CONCLUSIONS

Metformin usage may benefit KTRs, as evidenced by its association with a reduced risk of DCGF and the absence of MALA events. Randomized controlled trials are needed to validate these observational findings.

Predicting outcomes of continuous renal replacement therapy using body composition monitoring: a deep-learning approach

Fluid balance is a critical prognostic factor for patients with severe acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). This study evaluated whether repeated fluid balance monitoring could improve prognosis in this clinical population. This was a multicenter retrospective study that included 784 patients (mean age, 67.8 years; males, 66.4%) with severe AKI requiring CRRT during 2017-2019 who were treated in eight tertiary hospitals in Korea. Sequential changes in total body water were compared between patients who died (event group) and those who survived (control group) using mixed-effects linear regression analyses. The performance of various machine learning methods, including recurrent neural networks, was compared to that of existing prognostic clinical scores. After adjusting for confounding factors, a marginal benefit of fluid balance was identified for the control group compared to that for the event group (p = 0.074). The deep-learning model using a recurrent neural network with an autoencoder and including fluid balance monitoring provided the best differentiation between the groups (area under the curve, 0.793) compared to 0.604 and 0.606 for SOFA and APACHE II scores, respectively. Our prognostic, deep-learning model underlines the importance of fluid balance monitoring for prognosis assessment among patients receiving CRRT.

Metabolomic profiling of overnight peritoneal dialysis effluents predicts the peritoneal equilibration test type

This study primarily aimed to evaluate whether peritoneal equilibration test (PET) results can be predicted through the metabolomic analysis of overnight peritoneal dialysis (PD) effluents. From a total of 125 patients, overnight PD effluents on the day of the first PET after PD initiation were analyzed. A modified 4.25% dextrose PET was performed, and the PET type was categorized according to the dialysate-to-plasma creatinine ratio at the 4-h dwell time during the PET as follows: high, high average, low average, or low transporter. Nuclear magnetic resonance (NMR)-based metabolomics was used to analyze the effluents and identify the metabolites. The predictive performances derived from the orthogonal projection to latent structure discriminant analysis (OPLS-DA) modeling of the NMR spectrum were estimated by calculating the area under the curve (AUC) using receiver operating characteristic curve analysis. The OPLS-DA score plot indicated significant metabolite differences between high and low PET types. The relative concentrations of alanine and creatinine were greater in the high transporter type than in the low transporter type. The relative concentrations of glucose and lactate were greater in the low transporter type than in the high transporter type. The AUC of a composite of four metabolites was 0.975 in distinguish between high and low PET types. Measured PET results correlated well with the total NMR metabolic profile of overnight PD effluents.

Inflammatory chemokine (C-C motif) ligand 8 inhibition ameliorates peritoneal fibrosis

Peritoneal fibrosis (PF) is an irreversible complication of peritoneal dialysis (PD) that leads to loss of peritoneal membrane function. We investigated PD effluent and serum levels and the tissue expression of chemokine (C-C motif) ligand 8 (CCL8) in patients with PD. Additionally, we investigated their association with PF in a mouse model. Eighty-two end-stage renal disease (ESRD) patients with PD were examined. CCL8 levels were measured via enzyme-linked immunosorbent assays in PD effluents and serum and analyzed with peritoneal transport parameters. Human peritoneal mesothelial cells (hPMCs) were obtained from the PD effluents of 20 patients. Primary cultured hPMCs were treated with recombinant (r) transforming growth factor (TGF)-β, and CCL8 expression was assessed via western blotting. As the duration of PD increased, the concentration of CCL8 in PD effluents significantly increased. Correlations between peritoneal transport parameters and dialysate CCL8 levels were observed. Western blotting analysis showed that CCL8 was upregulated via rTGF-β treatment, accompanied by increases in markers of inflammation, fibrosis, senescence, and apoptosis in hPMCs after induction of fibrosis with rTGF-β. Anti-CCL8 monoclonal antibody (mAb) treatment suppressed the rTGF-β-induced increase in all analyzed markers. Immunohistochemical analysis revealed that CCL8 along with fibrosis- and inflammation-related markers were significantly increased in the PF mouse model. Functional blockade of CCL8 using a CCR8 inhibitor (R243) abrogated peritoneal inflammation and fibrosis in vivo. In conclusion, high CCL8 levels in PD effluents may be associated with an increased risk of PD failure, and the CCL8 pathway is associated with PF. CCL8 blockade can ameliorate peritoneal inflammation and fibrosis.

Association between physical activity and risk of renal function decline and mortality in community-dwelling older adults: a nationwide population-based cohort study

BACKGROUND

Physical activity (PA) is an important risk factor associated with health outcomes. However, the relationship between PA and kidney function decline in older adults remains unclear. We examined the influence of PA on kidney function decline and mortality in community-dwelling older adults.

METHODS

Adults aged ≥ 65 years with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m² who had available health checkup data from 2009 to 2010 were included. The cohort was followed annually through December 2015 for anthropometric, sociodemographic, and medical information including outcomes and biennially for laboratory information from the health checkup. We divided these patients into three groups according to self-reported PA (Inactive group: no leisure-time PA, Active group: vigorous activity for at least 80 min/week or a sum of moderate-intensity activity and walking for at least 300 min/week, Low-active group: level of PA between the definitions of the other two groups). Associations between the intensity of PA and death, cardiovascular death, and ≥ 50% eGFR decline were investigated.

RESULTS

Among 102,353 subjects, 32,984 (32.23%), 54,267 (53.02%), and 15,102 (14.75%) were classified into the inactive, low-active, and active groups, respectively. The active group was younger, contained a higher proportion of men, and had higher frequencies of hypertension, diabetes mellitus, drinking, and smoking than the other groups. The active group had significantly lower incidence rates of mortality, cardiovascular mortality, and kidney function decline than the other groups (all p < 0.001). The active group also showed lower all-cause (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.70-0.82) and cardiovascular mortality (HR, 0.64; 95% CI, 0.53-0.78) and protection against ≥ 50% eGFR decline (HR, 0.81; 95% CI, 0.68-0.97) compared with the inactive group in the fully adjusted Cox proportional hazards regression model.

CONCLUSIONS

High PA was an independent modifiable lifestyle factor for reducing mortality and protecting against declines in kidney function in older adults.

Korean Society of Nephrology 2022 recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Association between homocysteinemia and mortality in CKD: A propensity-score matched analysis using NHANES-National Death Index

Hyperhomocysteinemia (HHcy) is considered a risk factor for cardiovascular disease (CVD), including chronic kidney disease (CKD). In this study, we investigated the association between levels of serum homocysteine (Hcy) and mortality, inferred from the presence of CKD. Our study included data of 9895 participants from the 1999 to 2016 National Health and Nutrition Examination Surveys (NHANES). Multivariable-adjusted Cox proportional hazard models using propensity-score, were used to examine dose-response associations between Hcy level and mortality. A total of 9895 participants, 1025 (10.3%) participants were diagnosed with CKD. In a multivariate Cox regression analysis including all participants, Hcy level was significantly associated with all-cause mortality in the nonCKD group, compared to the 1st quartile in the fully adjusted model (2nd quartile: hazard ratio (HR) 1.75, 95% confidence interval (CI) 1.348-2.274, P < .001; 3rd quartile: HR 2.22, 95% CI 1.726-2.855, P < .001; 4th quartile: HR 3.77, 95% CI 2.952-4.830, P < .001). However, this finding was not observed in the CKD group. The observed pattern was similar after propensity score matching. In the nonCKD group, overall mortality increased in proportion to Hcy concentration (2nd quartile: HR 2.19, 95% CI 1.299-3.709, P = .003; 3rd quartile: HR 2.60, 95% CI 1.570-4.332, P < .001; 4th quartile: HR 3.72, 95% CI 2.254-6.139, P < .001). However, the risk of all-cause mortality according to the quartile of Hcy level, did not increase in the CKD group. This study found a correlation between the Hcy level and mortality rate only in the nonCKD group. These altered risk factor patterns may be attributed to protein-energy wasting or chronic inflammation status, that is accompanied by CKD.

Korean Society of Nephrology 2022 Recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Executive summary of the Korean Society of Nephrology 2021 clinical practice guideline for optimal hemodialysis treatment

The Korean Society of Nephrology (KSN) has published a clinical practice guideline (CPG) document for maintenance hemodialysis (HD). The document, 2021 Clinical Practice Guideline on Optimal HD Treatment, is based on an extensive evidence-oriented review of the benefits of preparation, initiation, and maintenance therapy for HD, with the participation of representative experts from the KSN under the methodologists' support for guideline development. It was intended to help clinicians participating in HD treatment make safer and more effective clinical decisions by providing user-friendly guidelines. We hope that this CPG will be meaningful as a recommendation in practice, but not on a regulatory rule basis, as different approaches and treatments may be used by health care providers depending on the individual patient's condition. This CPG consists of eight sections and 15 key questions. Each begins with statements that are graded by the strength of recommendations and quality of the evidence. Each statement is followed by a summary of the evidence supporting the recommendations. There are also a link to full-text documents and lists of the most important reports so that the readers can read further (most of this is available online).

Blockade of STAT3 signaling alleviates progression of acute kidney injury-to-chronic kidney disease through anti-apoptosis

Signal transducer and activator of transcription 3 (STAT3) is a pivotal mediator of IL-6-type cytokine signaling. However, the roles of its full-length and truncated isoforms in acute kidney injury (AKI) and its transition to chronic kidney disease (CKD) remain elusive. Herein, the role of STAT3 isoforms in AKI-to-CKD transition was characterized using an ischemia-reperfusion injury (IRI) mouse model. IRI was induced in C57BL/6 mice. Stattic^®, a STAT3 inhibitor, was administered to the mice 3 h prior to IRI. Intrarenal cytokine expression was quantified using real-time PCR, and FACS analysis was performed. The effect of Stattic^® on human tubular epithelial cells (TECs) cultured under hypoxic conditions was also evaluated. Phosphorylated STAT3 isoforms were detected by western blotting. Stattic^® treatment attenuated IRI-induced tubular damage and inflammatory cytokine/chemokine expression, while decreasing macrophage infiltration and fibrosis in mouse unilateral IRI and UUO models. Similarly, in vitro STAT3 inhibition downregulated fibrosis and apoptosis in 72-h hypoxia-induced human TECs and reduced pSTAT3α-mediated inflammation. Moreover, pSTAT3 expression was increased in human acute tubular necrosis and CKD tissues. STAT3 activation is associated with IRI progression, and STAT3-α may be a significant contributor. Hence, STAT3 may affect AKI-to-CKD transition, suggesting a novel strategy for AKI management with STAT3 inhibitors.

Impact of DBP on all-cause and cardiovascular mortality: results from the National Health and Nutrition Examination survey, 1999-2014

INTRODUCTION

Hypertension is common and has a significant effect on cardiovascular morbidity and death. However, despite the development of several guidelines to manage SBP, there is little research or guidance on the evaluation and management of DBP or isolated diastolic hypertension (IDH).

METHOD

To determine the association of DBP with all-cause and cardiovascular mortality, we used NHANES data from 1999 to 2014 and included adults aged at least 18 years. The relationship between DBP, IDH and all-cause, cardiovascular mortality was evaluated.

RESULTS

Of the 35 109 participants, all-cause death occurred in 10.6%, and cardiovascular death occurred in 2.1% over a median follow-up of 7.2 years. Multivariate Cox regression analysis revealed that the risk of all-cause mortality was significantly higher in the lowest (≤56.9 mmHg) DBP groups than in the reference group (DBP 74-76.9 mmHg). However, the risk of cardiovascular mortality was significantly higher in the lowest and highest (≥83 mmHg) DBP group than in the reference group. The risk of all-cause mortality was higher for most groups with SBP at least 140 mmHg than for the reference group with DBP 74-76.9 mmHg and SBP 100-139.9 mmHg. Both the 2018 ESC/NICE and the 2017 AHA/ACC-defined IDH was not significantly associated with all-cause mortality.

CONCLUSION

DBP and all-cause mortality had an inverse relationship, whereas DBP and cardiovascular mortality had a U-shaped relationship, with the DBP reference group having the lowest risk for all-cause and cardiovascular mortality. There was no significant relationship between IDH and death.

Evaluating a shared decision-making intervention regarding dialysis modality: development and validation of self-assessment items for patients with chronic kidney disease

Background

Shared decision-making is a two-way symmetrical communication process in which clinicians and patients work together to achieve the best outcome. This study aimed to develop self-assessment items as a decision aid for choosing a dialysis modality in patients with chronic kidney disease (CKD) and to assess the construct validity of the newly developed items.

Methods

Five focus group interviews were performed to extract specific self-assessment items regarding patient values in choosing a dialysis modality. After survey items were refined, a survey of 330 patients, consisting of 152 hemodialysis (HD) and 178 peritoneal dialysis (PD) patients, was performed to validate the self-assessment items.

Results

The self-assessment for the decision aid was refined to 35 items. The structure of the final items appeared to have three dimensions of factors; health, lifestyle, and dialysis environment. The health factor consisted of 12 subscales (α = 0.724), the lifestyle factor contained 11 subscales (α = 0.624), and the dialysis environment factor was represented by 12 subscales (α = 0.694). A structural equation model analysis showed that the relationship between the decision aid factors (health, lifestyle, and dialysis environment), patients’ CKD perception, and cognition of shared decision-making differed between HD patients and PD patients.

Conclusion

We developed and validated self-assessment items as part of a decision aid to help patients with CKD. This attempt may assist CKD patients in making informed and shared decisions closely aligned with their values when considering dialysis modality.

Red blood cell distribution width as a predictor of mortality among patients regularly visiting the nephrology outpatient clinic

The association between increased red blood cell distribution width (RDW) and mortality among patients treated on an outpatient basis in the nephrology outpatient clinic is unclear. Therefore, our study aimed to investigate the association between baseline and time-averaged RDW and mortality risk in patients treated in our nephrology outpatient clinic. Our multi-center retrospective analysis was based on data of 16,417 outpatient nephrology patients with available baseline renal function and RWD values. The median baseline RDW was 13.0% (range, 10.0–32.1%). The high-RDW group was defined as the top quartile (≥ 13.8%, n = 4302). The crude mortality rate was 15.0% (n = 1806) at a median follow-up of 127.5 months. From the results of the multivariate Cox proportional hazards regression model adjusted for covariates, including eGFR, hemoglobin, and factors of anemia treatment, patients with a high time-averaged RDW had increased mortality risk (adjusted hazard ratio, 1.505; 95% confidence interval, 1.326–1.708; P < 0.001), irrespective of sex, presence of anemia, and chronic kidney disease, except in individuals aged < 45 years. Thus, increased baseline and time-averaged RDW were significantly associated with increased mortality in patients aged > 45 years treated on an outpatient basis in the nephrology clinic.

Executive Summary of the Korean Society of Nephrology 2021 Clinical Practice Guideline for Optimal Hemodialysis Treatment

The Korean Society of Nephrology (KSN) has published a clinical practice guideline (CPG) document for maintenance hemodialysis (HD). The document, 2021 Clinical Practice Guideline on Optimal HD Treatment, is based on an extensive evidence-oriented review of the benefits of preparation, initiation, and maintenance therapy for HD, with the participation of representative experts from the KSN under the methodologists’ support for guideline development. It was intended to help clinicians participating in HD treatment make safer and more effective clinical decisions by providing user-friendly guidelines. We hope that this CPG will be meaningful as a recommendation in practice, but not on a regulatory rule basis, as different approaches and treatments may be used by health care providers depending on the individual patient’s condition. This CPG consists of eight sections and 15 key questions. Each begins with statements that are graded by the strength of recommendations and quality of the evidence. Each statement is followed by a summary of the evidence supporting the recommendations. There is also a link to full-text documents and lists of the most important reports so that the readers can read further (most of this is available online).

Effect of shared decision-making education on physicians' perceptions and practices of end-of-life care in Korea

Background

Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea.

Methods

A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals.

Results

A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low.

Conclusion

The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required.

First snapshot on behavioral characteristics and related factors of patients with chronic kidney disease in South Korea during the COVID-19 pandemic (June to October 2020)

Background

The recent novel coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented changes in behavior. We evaluated the current status of precautionary behavior and physical activity in chronic kidney disease (CKD) patients during the COVID-19 pandemic.

Methods

A population of CKD patients (n = 306) registered in the Study on Kidney Disease and Environmental Chemicals (SKETCH, Clinical Trial No. NCT04679168) cohort recruited from June 2020 to October 2020 was included in the study. We conducted a questionnaire survey related to risk perception of COVID-19, precautionary behavior, and physical activity.

Results

There were 187 patients (61.1%) with estimated glomerular filtration rate of <45 mL/min/1.73 m². This population showed a higher degree of risk perception for COVID-19 than the general population. Age was the most significant determinant of risk perception among CKD patients. During the pandemic, social distancing and hygiene-related behavior were significantly increased (p < 0.001). The frequency of exercise was decreased only in those who took regular exercise, without diabetes, or with a lower Charlson comorbidity index (CCI) (p < 0.001), with no change among the other groups. Socioeconomic status and comorbidities significantly affected behavioral characteristics regardless of the category. Education and income were significantly associated with precautionary behaviors such as staying at home and hand sanitizer use. Patients with higher CCI status significantly increased frequency of exercise (adjusted odds ratio, 2.10; 95% confidence interval, 1.01–4.38).

Conclusion

CKD patients showed higher risk perception with active precautionary behavioral changes than the general population. Healthcare providers should be aware of the characteristics to comprise precautionary behavior without reducing physical activity.

Smart Decentralization of Personal Health Records with Physician Apps and Helper Agents on Blockchain: Platform Design and Implementation Study

Background

The Health Avatar Platform provides a mobile health environment with interconnected patient Avatars, physician apps, and intelligent agents (termed IoA³) for data privacy and participatory medicine; however, its fully decentralized architecture has come at the expense of decentralized data management and data provenance.

Objective

The introduction of blockchain and smart contract technologies to the legacy Health Avatar Platform with a clinical metadata registry remarkably strengthens decentralized health data integrity and immutable transaction traceability at the corresponding data-element level in a privacy-preserving fashion. A crypto-economy ecosystem was built to facilitate secure and traceable exchanges of sensitive health data.

Methods

The Health Avatar Platform decentralizes patient data in appropriate locations (ie, on patients’ smartphones and on physicians’ smart devices). We implemented an Ethereum-based hash chain for all transactions and smart contract–based processes to guarantee decentralized data integrity and to generate block data containing transaction metadata on-chain. Parameters of all types of data communications were enumerated and incorporated into 3 smart contracts, in this case, a health data transaction manager, a transaction status manager, and an application programming interface transaction manager. The actual decentralized health data are managed in an off-chain manner on appropriate smart devices and authenticated by hashed metadata on-chain.

Results

Metadata of each data transaction are captured in a Health Avatar Platform blockchain node by the smart contracts. We provide workflow diagrams each of the 3 use cases of data push (from a physician app or an intelligent agents to a patient Avatar), data pull (request to a patient Avatar by other entities), and data backup transactions. Each transaction can be finely managed at the corresponding data-element level rather than at the resource or document levels. Hash-chained metadata support data element–level verification of data integrity in subsequent transactions. Smart contracts can incentivize transactions for data sharing and intelligent digital health care services.

Conclusions

Health Avatar Platform and interconnected patient Avatars, physician apps, and intelligent agents provide a decentralized blockchain ecosystem for health data that enables trusted and finely tuned data sharing and facilitates health value-creating transactions with smart contracts.

NK1.1- natural killer T cells upregulate interleukin-17 expression in experimental lupus nephritis

Interleukin (IL)-17-secreting invariant natural killer T (NKT) cells are involved in several inflammatory diseases. However, their role in lupus nephritis (LN) has not been fully characterized. Samples from patients with LN or glomerulonephritis and healthy controls were obtained, and elevated IL-17+ NKT cell numbers and IL-17 expression were observed in blood cells and kidneys, respectively, in patients with LN. Comparison of a mouse model of experimental autoimmune LN with the parental strain (NKT-deficient B6.CD1d-/- mice) revealed improved proteinuria, disease severity, and histopathology and decreased levels of chemokine (C-X-C motif) ligand 16 and T cell receptor-α variable 14 expression. Spleens and kidneys of B6.CD1d-/- mice also showed downregulation of inflammatory markers and IL-17. In coculture with renal mesangial and NKT cells, inflammatory markers and IL-17 were upregulated following α-galactosylceramide treatment and downregulated after treatment with IL-17-blocking antibodies. This was most prominent with killer cell lectin-like receptor subfamily B member 1 C (NK1.1)- NKT cells. Thus, IL-17 is upregulated in LN. Activation of NKT cells regulates IL-17-related immune responses systemically and in the kidneys, primarily via NK1.1- NKT cells. IL-17-secreting NK1.1- NKT cells could serve as diagnostic and therapeutic targets for LN.NEW & NOTEWORTHY This study makes a significant contribution to the literature because our results indicate that IL-17 is upregulated in lupus nephritis and that natural killer T (NKT) cells are involved in its pathogenesis. Activation of NKT cells regulates IL-17-related immune responses, both systemically and in the kidney, and this mainly involves NK1.1- NKT cells. Furthermore, IL-17-secreting NK1.1- NKT cells could serve as a diagnostic and therapeutic target for lupus nephritis.

Different Seasonal Variations of Potassium in Hemodialysis Patients with High Longitudinal Potassium Levels: A Multicenter Cohort Study Using DialysisNet

PURPOSE

To determine seasonal variations in serum potassium levels among hemodialysis patients.

MATERIALS AND METHODS

This was a multicenter cohort study of patients whounderwent hemodialysis and were registered in DialysisNet at our four associated general hospitals between January and December 2016. Month-to-month potassium variability was quantified as SD/√{n/(n-1)}, and a non-hierarchical method was used to cluster groups according to potassium trajectories. Seasonal variations in potassium levels were analyzed using a cosinor analysis.

RESULTS

The analysis was performed on 279 patients with a mean potassium level of 5.08±0.58 mmol/L. After clustering, 52.3% (n=146) of patients were included in the moderate group (K⁺, 4.6±0.4 mmol/L) and 47.7% (n=133) in the high group (K⁺, 5.6±0.4 mmol/L). The mean potassium level peaked in January in the moderate group (4.83±0.74 mmol/L) and in August in the high group (5.51±0.70 mmol/L). In the high potassium group, potassium levels were significantly higher in summer than in autumn (p<0.001) and spring (p=0.007). Month-to-month potassium variability was greater in the high group than in the moderate group (0.59±0.19 mmol/L vs. 0.52±0.21 mmol/L, respectively, p=0.012). Compared to patients in the first quartile of potassium variability (≤0.395 mmol/L), those with higher variability (2nd-4th quartiles) were 2.8-4.2 fold more likely to be in the high potassium group.

CONCLUSION

Different seasonal patterns of serum potassium were identified in the moderate and high potassium groups, with potassium levels being significantly higher in the summer season in the high potassium group and in winter for the moderate potassium group.

Low serum total CO2 and its association with mortality in patients being followed up in the nephrology outpatients clinic

Large-scale studies have not been conducted to assess whether serum hypobicarbonatemia increases the risk for kidney function deterioration and mortality among East-Asians. We aimed to determine the association between serum total CO₂ (TCO₂) concentrations measured at the first outpatient visit and clinical outcomes. In this multicenter cohort study, a total of 42,231 adult nephrology outpatients from 2001 to 2016 were included. End-stage renal disease (ESRD) patients on dialysis within 3 months of the first visit were excluded. Instrumental variable (IV) was used to define regions based on the proportion of patients with serum TCO₂ < 22 mEq/L. The crude mortality rate was 12.2% during a median 77.0-month follow-up period. The Cox-proportional hazard regression model adjusted for initial kidney function, alkali supplementation, and the use of diuretics demonstrated that low TCO₂ concentration was not associated with progression to ESRD, but significantly increased the risk of death. The IV analysis also confirmed a significant association between initial TCO₂ concentration and mortality (HR 0.56; 95% CI 0.49–0.64). This result was consistently significant regardless of the underlying renal function. In conclusion, low TCO₂ levels are significantly associated with mortality but not with progression to ESRD in patients with ambulatory care.

Multisample Mass Spectrometry-Based Approach for Discovering Injury Markers in Chronic Kidney Disease

Urinary proteomics studies have primarily focused on identifying markers of chronic kidney disease (CKD) progression. Here, we aimed to determine urinary markers of CKD renal parenchymal injury through proteomics analysis in animal kidney tissues and cells and in the urine of patients with CKD. Label-free quantitative proteomics analysis based on liquid chromatography-tandem mass spectrometry was performed on urine samples obtained from 6 normal controls and 9, 11, and 10 patients with CKD stages 1, 3, and 5, respectively, and on kidney tissue samples from a rat CKD model by 5/6 nephrectomy. Tandem mass tag-based quantitative proteomics analysis was performed for glomerular endothelial cells (GECs) and proximal tubular epithelial cells (PTECs) before and after inducing 24-h hypoxia injury. Upon hierarchical clustering, out of 858 differentially expressed proteins (DEPs) in the urine of CKD patients, the levels of 416 decreased and 403 increased sequentially according to the disease stage, respectively. Among 2965 DEPs across 5/6 nephrectomized and sham-operated rat kidney tissues, 86 DEPs showed same expression patterns in the urine and kidney tissue. After cross-validation with two external animal proteome data sets, 38 DEPs were organized; only ten DEPs, including serotransferrin, gelsolin, poly ADP-ribose polymerase 1, neuroblast differentiation-associated protein AHNAK, microtubule-associated protein 4, galectin-1, protein S, thymosin beta-4, myristoylated alanine-rich C-kinase substrate, and vimentin, were finalized by screening human GECs and PTECs data. Among these ten potential candidates for universal CKD marker, validation analyses for protein S and galectin-1 were conducted. Galectin-1 was observed to have a significant inverse correlation with renal function as well as higher expression in glomerulus with chronic injury than protein S. This constitutes the first multisample proteomics study for identifying key renal-expressed proteins associated with CKD progression. The discovered proteins represent potential markers of chronic renal cell and tissue damage and candidate contributors to CKD pathophysiology.

Korean clinical practice guidelines for preventing transmission of coronavirus disease 2019 (COVID-19) in hemodialysis facilities

Coronavirus disease 2019 (COVID-19) is a highly contagious viral disease that is caused by the novel virus Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). COVID-19 has become pandemic since December 2019, when the first case developed in Wuhan, China. Patients receiving hemodialysis are more vulnerable to viral transmission because their immune functions are impaired and they receive treatment within a narrow space. Calling on previous experience with Middle East Respiratory Syndrome during the 2015 outbreak, the joint committee of the Korean Society of Nephrology and the Korean Society of Dialysis Therapy quickly formed a COVID-19 task force team to develop a manual before the first index case was diagnosed in the hemodialysis unit. This special article introduces clinical practice guidelines to prevent secondary transmission of COVID-19 within hemodialysis facilities, which were developed to protect patients, healthcare workers, and caregivers from this highly transmissible virus. The areas of infection control covered by these guidelines include standard precautions, performing dialysis therapy for confirmed or suspected cases, performing cohort isolation for contact patients, and disease monitoring and contact surveillance. We hope these guidelines help healthcare workers and hemodialysis patients around the world cope with the COVID-19 pandemic.

P1607CD 137 SIGNALING IN REGULATORY DENDRITIC CELLS IS REQUIRED FOR SUPPRESSING A SYSTEMIC INFLAMMATION IN THE BM12-INDUCIBLE MODEL OF SYSTEMIC LUPUS ERYTHEMATOSUS

Background and Aims

Although CD137 is well known as a costimulatory receptor in T cells, limited information is available for its immunoregulatory function. Here, we report that CD137 signaling maintains CD11b+ regulatory dendritic cells (DCs) that can suppress activation of donor TH1 and TH17 CD4+ T cells in chronic graft-versus-host disease (GVHD).

Method

Chronic GVHD can be induced by mouse BMT models in which donor and recipient strain combination is MHC class I identical but MHC II mismatched. This chronic GVHD model recapitulates human SLE.

Results

: The deletion of CD137 in recipient mice shifted the disease phenotype toward acute GVHD, which was caused by the activation of donor T cells. CD137-/- recipients had had characteristic changes associated with acute GVHD: 1) there were defects in differentiation of T follicular helper (TFH) cells, germinal-center B cells, and plasma cells, and production of anti-DNA IgG1 autoantibody; 2) their splenic DCs showed dysregulated expression of DC-specific transcription factors and pro-inflammatory genes, and 3) there were strong activation of donor T cells but decreased Treg cells in the CD137-/- recipient spleen. CD11b+ splenic DCs stimulated with agnostic anti-CD137 antibody and CpG markedly increased expression of immunomodulatory genes, and such regulatory DCs inhibited acute GVHD in CD137-/- recipients. Their suppressive action was mediated through IL-10 that is indispensable for the induction and expansion of peripheral Treg cells.

Conclusion

Our study identifies CD137 signaling in DCs as an important braking point to prevent systemic inflammation, and this control system may be considered as a therapeutic strategy for a variety of inflammatory and autoimmune diseases.

Prediction of the Mortality Risk in Peritoneal Dialysis Patients using Machine Learning Models: A Nation-wide Prospective Cohort in Korea

Herein, we aim to assess mortality risk prediction in peritoneal dialysis patients using machine-learning algorithms for proper prognosis prediction. A total of 1,730 peritoneal dialysis patients in the CRC for ESRD prospective cohort from 2008 to 2014 were enrolled in this study. Classification algorithms were used for prediction of N-year mortality including neural network. The survival hazard ratio was presented by machine-learning algorithms using survival statistics and was compared to conventional algorithms. A survival-tree algorithm presented the most accurate prediction model and outperformed a conventional method such as Cox regression (concordance index 0.769 vs 0.745). Among various survival decision-tree models, the modified Charlson Comorbidity index (mCCI) was selected as the best predictor of mortality. If peritoneal dialysis patients with high mCCI (>4) were aged ≥70.5 years old, the survival hazard ratio was predicted as 4.61 compared to the overall study population. Among the various algorithm using longitudinal data, the AUC value of logistic regression was augmented at 0.804. In addition, the deep neural network significantly improved performance to 0.841. We propose machine learning-based final model, mCCI and age were interrelated as notable risk factors for mortality in Korean peritoneal dialysis patients.

Post-traumatic stress symptoms in hemodialysis patients with MERS-CoV exposure

Background

Post-traumatic stress symptoms can occur in patients with medical illness. During the Middle East Respiratory Syndrome (MERS) outbreak in South Korea in 2015, some dialysis patients in three centers who were incidentally exposed to patients or medical staff with confirmed MERS-CoV infection were isolated to interrupt the spread of the infection. We aimed to investigate post-traumatic stress symptoms and risk factors among these patients.

Materials and methods

In total, 116 hemodialysis (HD) patients in contact with MERS-CoV-confirmed subjects were isolated using three strategies, namely, single room isolation, cohort isolation, and self-quarantine. We used the Impact of Event Scale-Revised-Korean (IES-R-K) to examine post-traumatic stress symptoms at 12 months after the isolation period.

Results

Of the 116 HD patients, 27 were lost to follow-up. Of the 89 patients, 67 (75.3%) completed the questionnaires. Single room isolation was used on 40 (58.8%) of the patients, cohort isolation on 20 (29.4%), and self-imposed quarantine on 8 (11.8%). In total, 17.9% of participants (n = 12) reported post-traumatic stress symptoms exceeding the IES-R-K’s cutoff point (≧18). Prevalence rates of IES-R-K ≧18 did not differ significantly according to isolation method. However, isolation duration was linearly associated with the IES-R-K score (standardized β coefficient − 0.272, P = 0.026). Scores in Avoidance, Emotional numbing and Dissociation subscale were higher in patients with longer isolation period.

Conclusion

MERS was a traumatic experience for quarantined HD patients. IES-R-K scores were not significantly different by isolation methods. However, short isolation was associated with post-traumatic stress symptoms.

Chemokine receptor 5 blockade modulates macrophage trafficking in renal ischaemic-reperfusion injury

Chemokine receptor 5 (CCR5) is a pivotal regulator of macrophage trafficking in the kidneys in response to an inflammatory cascade. We investigated the role of CCR5 in experimental ischaemic‐reperfusion injury (IRI) pathogenesis. To establish IRI, we clamped the bilateral renal artery pedicle for 30 min and then reperfused the kidney. We performed adoptive transfer of lipopolysaccharide (LPS)‐treated RAW 264.7 macrophages following macrophage depletion in mice. B6.CCR5^−/− mice showed less severe IRI based on tubular epithelial cell apoptosis than did wild‐type mice. CXCR3 expression in CD11b⁺ cells and inducible nitric oxide synthase levels were more attenuated in B6.CCR5^−/− mice. B6.CCR5^−/− mice showed increased arginase‐1 and CD206 expression. Macrophage‐depleted wild‐type mice showed more injury than B6.CCR5^−/− mice after M1 macrophage transfer. Adoptive transfer of LPS‐treated RAW 264.7 macrophages reversed the protection against IRI in wild‐type, but not B6.CCR5^−/− mice. Upon knocking out CCR5 in macrophages, migration of bone marrow‐derived macrophages from wild‐type mice towards primary tubular epithelial cells with recombinant CCR5 increased. Phospho‐CCR5 expression in renal tissues of patients with acute tubular necrosis was increased, showing a positive correlation with tubular inflammation. In conclusion, CCR5 deficiency favours M2 macrophage activation, and blocking CCR5 might aid in treating acute kidney injury.

Effect of isolation practice on the transmission of middle east respiratory syndrome coronavirus among hemodialysis patients: A 2-year prospective cohort study

Hemodialysis (HD) patients had a high rate of infection transmission and mortality during the middle east respiratory syndrome coronavirus (MERS-CoV) outbreak in Saudi Arabia. A standardized guideline on isolation technique for exposed HD patients is not available. Thus, this study aimed to evaluate the effect of different isolation strategies on the prevention of secondary viral transmission and clinical outcomes among exposed HD patients.During the 2015 MERS-CoV outbreak in Korea, 116 patients in 3 HD units were incidentally exposed to individuals with confirmed MERS-CoV infection and underwent different types of isolation, which were as follows: single-room isolation (n = 54, 47%), cohort isolation (n = 46, 40%), and self-imposed quarantine (n = 16, 13%). The primary outcome was rate of secondary viral transmission. The secondary outcome measures were changes in clinical and biochemical markers during the isolation period, difference in clinical and biochemical markers according to the types of isolation practice, and effect of isolation practice on patient survival.During a mean isolation period of 15 days, no further cases of secondary transmission were detected among HD patients. Plasma hemoglobin, serum calcium, and serum albumin levels and single-pool Kt/V decreased during the isolation period but normalized thereafter. Patients who were subjected to self-imposed quarantine had higher systolic and diastolic blood pressure, lower total cholesterol level, and lower Kt/V than those who underwent single-room or cohort isolation. During the 24-month follow-up period, 12 patients died. However, none of the deaths occurred during the isolation period, and no differences were observed in patient survival rate according to different isolation strategies.Although 116 participants in 3 HD units were incidentally exposed to MERS-CoV during the 2015 outbreak in Korea, strict patient surveillance and proper isolation practice prevented secondary transmission of the virus. Thus, a renal disaster protocol, which includes proper contact surveillance and isolation practice, must be established in the future to accommodate the needs of HD patients during disasters or outbreaks.

Real-world treatment patterns of renal anemia in hemodialysis patients: A multicenter cohort study performed using DialysisNet (RRAHD study)

A multicenter cohort study.The DialysisNet was previously developed for the management of hemodialysis (HD) patients based on the American Society for Testing and Materials Continuity of Care Records by metadata transformation. DialysisNet is a dialysis patient management program created by using the personal health record care platform to overcome the problems of registry studies, in real-time.Here, we aimed to investigate the pattern of treatment for renal anemia in HD patients using DialysisNet.We performed a multicenter cohort study among HD patients who were treated at one of the three Korean university-affiliated hospitals from January 2016 to December 2016. Subjects were divided into 4 hemoglobin variability groups by quartiles. The variable anemia treatment pattern was reviewed. To determine renal anemia treatment patterns, we automatically collected information on the practice of anemia treatment patterns such as erythropoietin stimulating agent (ESA) doses and administration frequencies, and targeted hemoglobin maintenance rate. Individual hemoglobin variabilities were expressed as (standard deviations)/(√(n/[n-1]).The records of 159 patients were analyzed (Hospital A: 35, Hospital B: 21, Hospital C: 103). Mean patients' age was 65.6 ± 12.8 years, and 61.6% were men. Overall, hemoglobin level was 10.5[7.43;13.93] g/dL. 158 (99.3%) patients were using ESA; and overall, the epoetin alfa dose was 33,000[4000;136,800] U per week. Hemoglobin levels (P = .206) and epoetin alfa doses were similar (P = .924) for patients with different hemoglobin variabilities. The hemoglobin target maintenance rate was lower in the highest hemoglobin variability group than in the lowest variability group (P = .045).In this study, detailed information on the actual anemia treatment patterns were obtained using the DialysisNet. We expect that DialysisNet will simplify and improve the renal anemia management for both dialysis patients and health care providers.

Long-term Mortality Risks Among Living Kidney Donors in Korea

RATIONALE & OBJECTIVE

Living kidney donors may have a higher risk for death and kidney failure. This study aimed to investigate the long-term mortality experience of living kidney donors compared with members of the general public in Korea who underwent voluntary health examinations.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

We first calculated standardized mortality ratios for 1,292 Korean living kidney donors who underwent donor nephrectomy between 1982 and 2016 and 72,286 individuals who underwent voluntary health examinations between 1995 and 2016. Next we compared survival between the 1,292 living kidney donors and a subgroup of the health examination population (n=33,805) who had no evident contraindications to living kidney donation at the time of their examinations. Last, a matched comparator group was created from the health examination population without apparent contraindication to donation by matching 4,387 of them to donors (n=1,237) on age, sex, body mass index, estimated glomerular filtration rate, urine dipstick albumin excretion, previously diagnosed hypertension and diabetes, and era.

EXPOSURES

Donor nephrectomy.

OUTCOMES

All-cause mortality and other clinical outcomes after kidney donation.

ANALYTICAL APPROACH

First, standardized mortality ratios were calculated separately for living kidney donors and the health examination population standardized to the general population. Second, we used Cox regression analysis to compare mortality between living kidney donors versus the subgroup of the health examination population without evident donation contraindications. Third, we used Cox regression analysis to compare mortality between living kidney donors and matched comparators from the health examination population without apparent contraindication to donation.

RESULTS

The living kidney donors and health examination population had excellent survival rates compared with the general population. 52 (4.0%) of 1,292 kidney donors died during a mean follow-up of 12.3±8.1 years and 1,072 (3.2%) of 33,805 in the health examiner subgroup without donation contraindications died during a mean follow-up of 11.4±6.1 years. Donor nephrectomy did not elevate the hazard for mortality after multivariable adjustment in kidney donors and the 33,805 comparators (adjusted HR, 1.01; 95% CI, 0.71-1.44; P=0.9). Moreover, living donors showed a similar mortality rate compared with the group of matched healthy comparators.

LIMITATIONS

Donors from a single transplantation center. Residual confounding owing to the observational study design.

CONCLUSIONS

Kidney donors experienced long-term rates of death comparable to nondonor comparators with similar health status.

Renin Angiotensin Aldosterone System Blockades Does Not Protect Residual Renal Function in Patients with Hemodialysis at 1 Year After Dialysis Initiation: A Prospective Observational Cohort Study

The beneficial effects of renin angiotensin aldosterone system (RAAS) blockade on residual renal function (RRF) in patients who have just initiated hemodialysis (HD) have been inconclusive. In this study, 935 patients with incident HD from a nationwide prospective observational cohort in Korea were included for analysis. The primary outcome showed that RRF as demonstrated by urine volume changes over 0, 3, and 12 months differed between the RAAS blockade and control groups. Mixed-effects linear regression was used to compare RRF between the groups. Patients in the RAAS group had a greater proportion of higher urine volume at study enrollment compared to the control group, but there was no difference in baseline characteristics, heart function, and dialysis-related indices. After adjusting for confounding factors, the RAAS group did not provide a significant benefit to RRF in a mixed-effects linear regression (p = 0.51). Male gender, high Charlson comorbidity index, diuretic use, and high weekly ultrafiltration volume were associated with faster decline in RRF. The RAAS group failed to provide a protective effect for the development of anuria 1 year after initiating dialysis based on the multivariate logistic regression (OR 0.73 95% CI 0.25-2.13, p = 0.57). In Korean patients with incident HD, RAAS blockade did not provide a protective effect for RRF after 1 year. Further research is needed to clarify the optimal treatment for preserving RRF in HD patients.

Factors affecting mortality during the waiting time for kidney transplantation: A nationwide population-based cohort study using the Korean Network for Organ Sharing (KONOS) database

BACKGROUND

Long waiting time for deceased donor kidney transplant is inevitable due to the scarcity of donor, resulting in highlighting the importance of waiting time care. We analyzed the Korean Network for Organ Sharing (KONOS) database to assess the impact of waiting time on post-transplant survival outcomes and investigate risk factors for mortality by waiting time based on a complete enumeration survey in Korea.

METHODS

We analyzed all persons aged over 18 years in deceased donor kidney transplant cases enrolled in the Korean Network for Organ Sharing (KONOS) database from January 2000 to January 2015. The primary end point was all-cause mortality after enrollment.

RESULTS

Of the 24,296 wait-listed subjects on dialysis, 5,255 patients received kidney transplants from deceased donors, with a median waiting time of 4.5 years. Longer waiting times had distinct deleterious effects on overall survival after transplantation. While waiting for a transplant, patients with diabetes were more likely to die before transplantation (HR 1.515, 95% CI 1.388-1.653, p<0.001). Age was another significant risk factor for mortality. Only 56% of people aged 65 years survived after 10 years of waiting, whereas 86% of people aged 35 years survived after 10 years. Moreover, women on the waiting list were more likely to live longer than men on the list.

CONCLUSIONS

More attention should be focused on patients with a higher risk of mortality while waiting for a deceased donor kidney transplant, such as patients with diabetes, those of advanced age, and those who are male.

Disaster preparedness for earthquakes in hemodialysis units in Gyeongju and Pohang, South Korea

In 2016 and 2017, there were earthquakes greater than 5.0 in magnitude on the Korean Peninsula, which has previously been considered an earthquake-free zone. Patients with chronic kidney disease are particularly vulnerable to earthquakes, as the term “renal disaster” suggests. In the event of a major earthquake, patients on hemodialysis face the risk of losing maintenance dialysis due to infrastructure disruption. In this review, we share the experience of an earthquake in Pohang that posed a serious risk to patients on hemodialysis. We review the disaster response system in Japan and propose a disaster preparedness plan with respect to hemodialysis. Korean nephrologists and staff in dialysis facilities should be trained in emergency response to mitigate risk from natural disasters. Dialysis staff should be familiar with the action plan for natural disaster events that disrupt hemodialysis, such as outages and water treatment system failures caused by earthquakes. Patients on hemodialysis also need to be educated about disaster preparedness. In the event of a disaster situation that results in dialysis failure, patients need to know what to do. At the local and national government level, long-term preparations should be made to handle renal disaster and patient safety logistics. Moreover, Korean nephrologists should also be prepared to manage cardiovascular disease and diabetes in disaster situations. Further evaluation and management of social and national disaster preparedness of hemodialysis units to earthquakes in Korea are needed.

Maternal and fetal outcomes of pregnancies in kidney donors: A 30-year comparative analysis of matched non-donors in a single center

Background

Woman kidney donors face obstetric complication risks after kidney donation, such as gestational hypertension and preeclampsia. Studies on childbirth-related complications among Asian women donors are scarce.

Methods

This retrospective cohort study included woman donors aged 45 years or younger at the time of kidney donation in a single tertiary hospital between 1985 and 2014. Pregnancy associated complications were investigated using medical records and telephone questionnaires for 426 pregnancies among 225 donors. Matched non-donor controls were selected by propensity score and the maternal and fetal outcomes were compared with those of donors. Primary outcomes were differences in maternal complications, and secondary outcomes were fetal outcomes in pregnancies of the donor and control groups.

Results

A total of 56 cases had post-donation pregnancies. The post-donation pregnancies group was younger at the time of donation and older at the time of delivery than the pre-donation pregnancies group, and there were no differences in primary outcomes between the groups except the proportion receiving cesarean section. Comparison of the complication risk between post-donation pregnancies and non-donor matched controls showed no significant differences in gestational hypertension, preeclampsia, or composite outcomes after propensity score matching including age at delivery, era at pregnancy, systolic blood pressure, body weight, and estimated glomerular filtration ratio (odds ratio, 0.63; 95% confidence interval, 0.19–2.14; P = 0.724).

Conclusion

This study revealed that maternal and fetal outcomes between woman kidney donors and non-donor matched controls were comparable. Studies with general population pregnancy controls are warranted to compare pregnancy outcomes for donors.

Terminal lucidity in the teaching hospital setting

Terminal lucidity is an unpredictable end-of-life experience that has invaluable implications in preparation for death. We retrospectively evaluated terminal lucidity at a university teaching hospital. Of 338 deaths that occurred during the study period (187 in the ICU and 151 in general wards), terminal lucidity was identified in 6 cases in general wards. Periods of lucidity ranged from several hours to 4 days. After experiencing terminal lucidity, half of the patients died within a week, and the remainder died within 9 days. More attention should be directed toward understanding terminal lucidity to improve end-of-life care in a meaningful way.