Silent gallbladder stone in kidney transplantation recipients: should it be treated? a retrospective cohort study

BACKGROUND

Treatment and follow-up strategies for silent gallbladder stones in patients before kidney transplantation (KT) remain unknown. Therefore, we aimed to elucidate the role of pre-KT cholecystectomy in preventing biliary and surgical complications.

MATERIALS AND METHODS

This study retrospectively analyzed 2,295 KT recipients and 3,443 patients waiting for KT at a single tertiary center from January 2005 to July 2022. The primary outcomes were the incidences of biliary and post-cholecystectomy complications in KT recipients. Firth's logistic regression model was used to assess the risk factors for biliary complications.

RESULTS

Overall, 543 patients awaiting KT and 230 KT recipients were found to have biliary stones. Among the KT recipients, 16 (7%) underwent cholecystectomy before KT, while others chose to observe their biliary stones. Pre-KT cholecystectomy patients did not experience any biliary complications, and 20 (9.3%) patients who chose to observe their stones experienced complications. Those who underwent cholecystectomy before KT developed fewer post-cholecystectomy complications (6.3%) compared with those who underwent cholecystectomy after KT (38.8%, P=0.042), including reduced occurrences of fatal postoperative complications based on the Clavien-Dindo classification. Multiple stones (odds ratio [OR], 3.09; 95% confidence interval [CI], 1.07-8.90; P=0.036), thickening of the gallbladder wall (OR, 5.39; 95% CI, 1.65-17.63; P=0.005), and gallstones>1 cm in size (OR 5.12, 95% CI: 1.92-13.69, P=0.001) were independent risk factors for biliary complications. Among patients awaiting KT, 23 (4.2%) underwent cholecystectomy during the follow-up, resulting in one post-cholecystectomy complication.

CONCLUSION

Gallstone-related biliary complications following KT and subsequent cholecystectomy was associated with more serious complications and worse treatment outcomes. Therefore, when KT candidates had risk factor for biliary complications, preemptive cholecystectomy for asymptomatic cholecystolithiasis could be considered to reduce further surgical risk.

The association of time-updated ambulatory blood pressure and renal progression in hypertensive patients with chronic kidney disease: post hoc analysis of ACCURATE study

OBJECTIVES

: This study aimed to evaluate the effect of time-updated ambulatory blood pressure on chronic kidney disease (CKD) progression in patients with hypertension.

METHODS

: Among patients with hypertension and CKD stages 3 and 4, enrolled in a clinical trial in which hypertension was treated based on office or ambulatory blood pressure (BP), participants assigned to the ambulatory BP were included in this study. Ambulatory BP was measured at the start of the study and 3, 6, and 18 months. Renal events were defined as a decrease in the estimated glomerular filtration rate (eGFR) by at least 30%, dialysis, or transplantation.

RESULTS

: A total of 21 cases of renal events were observed. For baseline BP, a multivariate Cox model revealed that neither office SBP nor any component of ambulatory SBP, including mean, day-time, night-time BPs was associated with the risk of renal events. For time-updated BP, a marginal structural model revealed that the office SBP was not associated with renal events [hazard ratio 1.03, 95% confidence interval (CI) 0.99-1.07, P  = 0.117], but higher ambulatory SBPs, including day-time (hazard ratio 1.05, 95% CI 1.01-1.10, P  = 0.014), night-time (hazard ratio 1.05, 95% CI 1.02-1.08, P  = 0.001), and mean (hazard ratio 1.06, 95% CI 1.02-1.10, P  = 0.002) ambulatory SBPs, were significantly associated with an increased risk of renal events.

CONCLUSION

: A higher time-updated ambulatory BP was associated with an increased risk of renal events in patients with hypertension and CKD, whereas baseline office and ambulatory BP, and time-updated office BP were not.

Menopausal hormone therapy and risk for dementia in women with CKD: A nationwide observational cohort study

AIM

The risk for dementia is increased in postmenopausal women. The incidences of premature menopause and dementia have increased in patients with chronic kidney disease (CKD). The potential benefits of hormone replacement therapy (HRT) on cognitive function may be a more critical issue for patients with CKD.

METHODS

Women aged >40 years with or without HRT were identified using the 2009 National Health Screening Questionnaire. Women who were newly diagnosed with CKD between 2009 and 2013 were enrolled. HRT was used as an exposure variable, and participants were followed from the day CKD was diagnosed to December 2019. The hazard ratio (HR) for dementia was evaluated using Cox proportional hazards regression analysis.

RESULTS

We included 755 426 postmenopausal women with CKD. The median follow-up period was 7.3 (IQR, 5.8-8.7) years. All-cause dementia, Alzheimer's disease, and vascular dementia occurred in 107 848 (14.3%), 87 833 (11.6%), and 10 245 (1.4%) women, respectively. HRT was significantly associated with a lower risk for dementia in the adjusted Cox regression model (all-cause dementia: HR 0.80; 95% confidence interval [CI] 0.78-0.82; p < 0.001; Alzheimer's disease: HR 0.80; 95% CI 0.77-0.82; p < 0.001; vascular dementia: HR 0.80; 95% CI 0.74-0.87; p < 0.001).

CONCLUSIONS

HRT was significantly associated with a lower risk for CKD-related cognitive dysfunction in postmenopausal women. Prospective studies are needed to determine whether HRT lowers the risk for dementia in menopausal women with CKD.

Non-indicated initiation of proton pump inhibitor and risk of adverse outcomes in patients with underlying chronic kidney disease: a nationwide, retrospective, cohort study

OBJECTIVE

Evidence related to the risk of kidney damage by proton pump inhibitor (PPI) initiation in patients with 'underlying' chronic kidney disease (CKD) remains scarce, although PPI use is generally associated with acute interstitial nephritis or incident CKD. We aimed to investigate the association between PPI initiation and the risk of adverse outcomes in patients with CKD in the absence of any deterministic indications for PPI usage.

DESIGN

Retrospective observational study.

SETTING

Korea National Health Insurance Service database from 2009 to 2017.

PARTICIPANTS

A retrospective cohort of new PPI and histamine H2-receptor antagonists (H2RA) users among people with CKD. Patients with a history of gastrointestinal bleeding or those who had an endoscopic or image-based upper gastrointestinal tract evaluation were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

The study subjects were followed to ascertain clinical outcomes including mortality, end-stage kidney disease (ESKD), myocardial infarction and stroke. The HRs of outcomes were measured using a Cox regression model after adjusting for multiple variables. We applied an inverse probability of treatment weighting (IPTW) model to control for residual confounders.

RESULTS

We included a total of 1038 PPI and 3090 H2RA users without deterministic indications for treatment. IPTW-weighted Cox regression analysis showed that PPI initiation was more significantly associated with a higher ESKD risk compared with that of H2RA initiation (adjusted HR 1.72 (95% CI 1.19 to 2.48)), whereas the risks of mortality or cardiovascular outcomes were similar between the two groups. In the subgroup analysis, multivariable Cox regression analysis showed that the association between PPI use and the progression to ESKD remained significant in non-diabetic and low estimated glomerular filtration rate (<60 mL/min/1.73 m2) groups (adjusted HR 1.72 (95% CI 1.19 to 2.48) and 1.63 (95% CI 1.09 to 2.43), respectively).

CONCLUSIONS

Initiation of PPI administration may not be recommended in patients with CKD without deterministic indication, as their usage was associated with a higher risk of ESKD.

Associations of metabolic variabilities and cardiovascular outcomes according to estimated glomerular filtration rate in chronic kidney disease: a nationwide observational cohort study

Background

The impact of baseline estimated glomerular filtration rate (eGFR) on the risk of adverse outcomes according to metabolic parameter variabilities in chronic kidney disease has rarely been investigated.

Methods

We conducted a retrospective nationwide cohort study using the National Health Insurance System data in Korea from 2007 to 2013 to identify individuals with three or more health screenings. The metabolic components variability was defined as intraindividual variability between measurements using the variability independent of the mean. The metabolic variability score was defined as the total number of high-variability metabolic components. Multivariable-adjusted Cox regression analysis was conducted to evaluate the risks of all-cause mortality, myocardial infarction, and ischemic stroke.

Results

During a mean follow-up of 6.0 ± 0.7 years, 223,531 deaths, 107,140 myocardial infarctions, and 116,182 ischemic strokes were identified in 9,971,562 patients. Low eGFR categories and higher metabolic variability scores were associated with a higher risk of adverse outcomes. The degree of association between metabolic variability and adverse outcomes was significantly larger in those with low eGFR categories than in those with preserved eGFR (p for interaction < 0.001). Representatively, those with high metabolic variability in the eGFR of <15 mL/min/1.73 m2 group showed a prominently higher risk for all-cause mortality (adjusted hazard ratio [aHR], 5.28; 95% confidence interval [CI], 4.02-6.94) when the degree was compared to the findings in those with preserved (eGFR of ≥60 mL/min/1.73 m2) kidney function (aHR, 2.55; 95% CI, 2.41-2.69).

Conclusion

The degree of adverse association between metabolic variability and poor prognosis is accentuated in patients with impaired kidney function.

Impact of albuminuria on early-onset type 2 diabetes mellitus: a nationwide population-based study

Background

Early-onset diabetes mellitus has a significant lifetime burden and is associated with higher morbidity and mortality. Since insulin resistance is one of the mechanisms of podocyte injury, we aimed to evaluate the effect of albuminuria on newly developed early-onset type 2 diabetes mellitus (T2DM).

Methods

We screened 6,891,399 subjects aged ≥20 and <40 years without a history of prediabetes or diabetes from the Korean National Health Insurance Service database between 2009 and 2012. A multivariate Cox proportional hazard model was used to identify the impact of albuminuria on early-onset T2DM.

Results

Among a total of 5,383,779 subjects, 62,148 subjects (1.2%) developed early-onset diabetes over 7.3 ± 1.2 years. Albuminuria was significantly associated with early-onset T2DM (adjusted hazard ratio [aHR], 1.62; 95% confidence interval [CI], 1.55-1.70) after adjustment for age, sex, anthropometric data, physical exercise status, serum glucose, and total cholesterol. The risk of early-onset T2DM increased more in subjects with more components of metabolic syndrome (MetS). Among each component of MetS, hypertriglyceridemia was prominently associated with early-onset T2DM (aHR, 2.02; 95% CI, 1.81-2.25) in subjects with albuminuria.

Conclusion

Dipstick albuminuria was significantly associated with early-onset T2DM in young adult populations. Close monitoring of albuminuria is warranted for disease risk modification, especially in subjects with MetS.

Cardiovascular and Mortality Risks in Young Health Screening Examinees With Marginal Estimated GFR

Introduction

Additional evidence is necessary to interpret kidney function parameters in young adults, particularly in those with marginal estimated glomerular filtration rate (eGFR) values. Therefore, we aimed to investigate the association between eGFR and adverse outcomes in general young adults.

Methods

We performed a nationwide retrospective cohort study using the health-screening database of South Korea. We included young adults aged 20-39 years without a history of major adverse cardiovascular events (MACE) or kidney failure, who underwent nationwide health screening in 2012. The study exposure was eGFR categorized into 15 ml/min per 1.73 m2 intervals. The risks of all-cause mortality and MACE were calculated using Cox regression analysis, adjusted for various clinicodemographic characteristics.

Results

In total, 3,132,409 young adults were included in this study. During a median follow-up of 7.3 years, marginal eGFR (60-75 ml/min per 1.73 m2) was not significantly associated with a higher risk of all-cause mortality (adjusted hazard ratio [aHR], 0.80 [0.74-0.87]). The results were similar for MACE outcomes (aHR, 0.94 [0.87-1.01]). Although the presence of dipstick albuminuria had a significant interaction with the association between eGFR categories and all-cause mortality (interaction term P = 0.028), the risks of all-cause mortality were not significantly higher (aHR, 0.98 [0.62, 1.55]) in those with albuminuria and eGFR 60-75 ml/min per 1.73 m2.

Conclusion

Marginal eGFR was not associated with higher risks of all-cause mortality and MACE in general young adults. Additional clinical investigations for incidentally found marginal eGFR values may be discouraged in general young adults.

Regulation of anti-inflammatory and antioxidant responses by methanol extract of Mikania cordata (Burm. f.) B. L. Rob. leaves via the inactivation of NF-κB and MAPK signaling pathways and activation of Nrf2 in LPS-induced RAW 264.7 macrophages

Mikania cordata (Burm. f.) B.L. Rob. has been traditionally used in tropical countries throughout Asia and Africa to treat gastric ulcers, dyspepsia, and dysentery. However, the mechanisms responsible for its anti-inflammatory and antioxidant activities are not fully understood. Therefore, this study sought to investigate the anti-inflammatory and antioxidant effects of methanol extracts of M. cordata (MMC) on inflammation and oxidative stress in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages and elucidate its underlying regulatory mechanism. MMC significantly suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW 264.7 macrophages by downregulating the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at both the mRNA and protein levels. Moreover, MMC effectively reduced the mRNA expression levels and production of pro-inflammatory cytokines, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). These suppressive effects of MMC on pro-inflammatory mediators and cytokines were mediated through the inhibition of transforming growth factor beta-activated kinase 1 (TAK1), which subsequently blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). MMC also upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2) by inducing the degradation of Kelch-like ECH-related protein 1 (Keap1), an Nrf2-specific E3 ligase. Accordingly, MMC enhanced Nrf2 target gene expression of anti-oxidative regulators such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). However, it had minimal effect on the DPPH radical scavenging capacity in vitro. Collectively, these findings demonstrate that MMC holds promise as a potential therapeutic agent for alleviating inflammation-related diseases and oxidative stress.

Comparison of cardiovascular event predictability between the 2009 and 2021 Chronic Kidney Disease Epidemiology Collaboration equations in a Korean chronic kidney disease cohort: the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease

BACKGROUND

The 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine-based estimated glomerular filtration rate (eGFRcr) equation contains a race component that is not based on biology and may cause a bias in results. Therefore, the 2021 eGFRcr and creatinine-cystatin C-based eGFR (eGFRcr-cysC) equations were developed with no consideration of race. This study compared the cardiovascular event (CVE) and all-cause mortality and CVE combined predictability among the three eGFR equations in Korean chronic kidney disease (CKD) patients.

METHODS

This study included 2,207 patients from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease. Receiver operating characteristic (ROC) and net reclassification improvement (NRI) index were used to compare the predictability of the study outcomes according to the 2009 eGFRcr, 2021 eGFRcr, and 2021 eGFRcr-cysC equations.

RESULTS

The overall prevalence of CVE and all-cause mortality were 9% and 7%, respectively. There was no difference in area under the curve of ROC for CVE and mortality and CVE combined among all three equations. Compared to the 2009 eGFRcr, both the 2021 eGFRcr (NRI, 0.013; 95% confidence interval [CI], - 0.002 to 0.028) and the eGFRcr-cysC (NRI, -0.001; 95% CI, -0.031 to 0.029) equations did not show improved CVE predictability. Similar findings were observed for mortality and CVE combined predictability with both the 2021 eGFRcr (NRI, -0.019; 95% CI, -0.039-0.000) and the eGFRcr-cysC (NRI, -0.002; 95% CI, -0.023 to 0.018).

CONCLUSION

The 2009 eGFRcr equation was not inferior to either the 2021 eGFRcr or eGFRcr-cysC equation in predicting CVE and the composite of mortality and CVE in Korean CKD patients.

Measured sodium excretion is associated with cardiovascular outcomes in non-dialysis CKD patients: results from the KNOW-CKD study

Background

There are insufficient studies on the effect of dietary salt intake on cardiovascular (CV) outcomes in chronic kidney disease (CKD) patients, and there is no consensus on the sodium (Na) intake level that increases the risk of CV disease in CKD patients. Therefore, we investigated the association between dietary salt intake and CV outcomes in CKD patients.

Methods

In the Korean cohort study for Outcome in patients with CKD (KNOW-CKD), 1,937 patients were eligible for the study, and their dietary Na intake was estimated using measured 24h urinary Na excretion. The primary outcome was a composite of CV events and/or all-cause death. The secondary outcome was a major adverse cardiac event (MACE).

Results

Among 1,937 subjects, there were 205 (10.5%) events for the composite outcome and 110 (5.6%) events for MACE. Compared to the reference group (urinary Na excretion< 2.0g/day), the group with the highest measured 24h urinary Na excretion (urinary Na excretion ≥ 8.0g/day) was associated with increased risk of both the composite outcome (hazard ratio 3.29 [95% confidence interval 1.00-10.81]; P = 0.049) and MACE (hazard ratio 6.28 [95% confidence interval 1.45-27.20]; P = 0.013) in a cause-specific hazard model. Subgroup analysis also showed a pronounced association between dietary salt intake and the composite outcome in subgroups of patients with abdominal obesity, female, lower estimated glomerular filtration rate (< 60 ml/min per 1.73m2), no overt proteinuria, or a lower urinary potassium-to-creatinine ratio (< 46 mmol/g).

Conclusion

A high-salt diet is associated with CV outcomes in non-dialysis CKD patients.

Role of pelitinib in the regulation of migration and invasion of hepatocellular carcinoma cells via inhibition of Twist1

BACKGROUND

Overexpression of Twist1, one of the epithelial-mesenchymal transition-transcription factors (EMT-TFs), is associated with hepatocellular carcinoma (HCC) metastasis. Pelitinib is known to be an irreversible epidermal growth factor receptor tyrosine kinase inhibitor that is used in clinical trials for colorectal and lung cancers, but the role of pelitinib in cancer metastasis has not been studied. This study aimed to investigate the anti-migration and anti-invasion activities of pelitinib in HCC cell lines.

METHODS

Using three HCC cell lines (Huh7, Hep3B, and SNU449 cells), the effects of pelitinib on cell cytotoxicity, invasion, and migration were determined by cell viability, wound healing, transwell invasion, and spheroid invasion assays. The activities of MMP-2 and -9 were examined through gelatin zymography. Through immunoblotting analyses, the expression levels of EMT-TFs (Snail1, Twist1, and ZEB1) and EMT-related signaling pathways such as mitogen-activated protein kinases (MAPKs) and Akt signaling pathways were measured. The activity and expression levels of target genes were analyzed by reporter assay, RT-PCR, quantitative RT-PCR, and immunoblotting analysis. Statistical analysis was performed using one-way ANOVA with Dunnett's Multiple comparison tests in Prism 3.0 to assess differences between experimental conditions.

RESULTS

In this study, pelitinib treatment significantly inhibited wound closure in various HCC cell lines, including Huh7, Hep3B, and SNU449. Additionally, pelitinib was found to inhibit multicellular cancer spheroid invasion and metalloprotease activities in Huh7 cells. Further investigation revealed that pelitinib treatment inhibited the migration and invasion of Huh7 cells by inducing Twist1 degradation through the inhibition of MAPK and Akt signaling pathways. We also confirmed that the inhibition of cell motility by Twist1 siRNA was similar to that observed in pelitinib-treated group. Furthermore, pelitinib treatment regulated the expression of target genes associated with EMT, as demonstrated by the upregulation of E-cadherin and downregulation of N-cadherin.

CONCLUSION

Based on our novel finding of pelitinib from the perspective of EMT, pelitinib has the ability to inhibit EMT activity of HCC cells via inhibition of Twist1, and this may be the potential mechanism of pelitinib on the suppression of migration and invasion of HCC cells. Therefore, pelitinib could be developed as a potential anti-cancer drug for HCC.

Anti-migration and anti-invasion effects of LY-290181 on breast cancer cell lines through the inhibition of Twist1

Breast cancer has become the most common cancer among women worldwide. Among breast cancers, metastatic breast cancer is associated with the highest mortality rate. Twist1, one of the epithelial-mesenchymal transition-regulating transcription factors, is known to promote the intravasation of breast cancer cells into metastatic sites. Therefore, targeting Twist1 to develop anti-cancer drugs might be a valuable strategy. In this study, LY-290181 dose-dependently inhibited migration, invasion, and multicellular tumor spheroid invasion in breast cancer cell lines. These anti-cancer effects of LY-290181 were mediated through the down-regulation of Twist1 protein levels. LY-290181 inhibited extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways. Therefore, our findings suggest that LY-290181 may serve as a basis for future research and development of an anti-cancer agent targeting metastatic cancers. [BMB Reports 2023; 56(7): 410-415].

Epigenome-wide association study of diabetic chronic kidney disease progression in the Korean population: the KNOW-CKD study

Since the etiology of diabetic chronic kidney disease (CKD) is multifactorial, studies on DNA methylation for kidney function deterioration have rarely been performed despite the need for an epigenetic approach. Therefore, this study aimed to identify epigenetic markers associated with CKD progression based on the decline in the estimated glomerular filtration rate in diabetic CKD in Korea. An epigenome-wide association study was performed using whole blood samples from 180 CKD recruited from the KNOW-CKD cohort. Pyrosequencing was also performed on 133 CKD participants as an external replication analysis. Functional analyses, including the analysis of disease-gene networks, reactome pathways, and protein-protein interaction networks, were conducted to identify the biological mechanisms of CpG sites. A phenome-wide association study was performed to determine the associations between CpG sites and other phenotypes. Two epigenetic markers, cg10297223 on AGTR1 and cg02990553 on KRT28 indicated a potential association with diabetic CKD progression. Based on the functional analyses, other phenotypes (blood pressure and cardiac arrhythmia for AGTR1) and biological pathways (keratinization and cornified envelope for KRT28) related to CKD were also identified. This study suggests a potential association between the cg10297223 and cg02990553 and the progression of diabetic CKD in Koreans. Nevertheless, further validation is needed through additional studies.

Novel Genetic Variants Associated with Chronic Kidney Disease Progression

SIGNIFICANCE STATEMENT

eGFR slope has been used as a surrogate outcome for progression of CKD. However, genetic markers associated with eGFR slope among patients with CKD were unknown. We aimed to identify genetic susceptibility loci associated with eGFR slope. A two-phase genome-wide association study identified single nucleotide polymorphisms (SNPs) in TPPP and FAT1-LINC02374 , and 22 of them were used to derive polygenic risk scores that mark the decline of eGFR by disrupting binding of nearby transcription factors. This work is the first to identify the impact of TPPP and FAT1-LINC02374 on CKD progression, providing predictive markers for the decline of eGFR in patients with CKD.

BACKGROUND

The incidence of CKD is associated with genetic factors. However, genetic markers associated with the progression of CKD have not been fully elucidated.

METHODS

We conducted a genome-wide association study among 1738 patients with CKD, mainly from the KoreaN cohort study for Outcomes in patients With CKD. The outcome was eGFR slope. We performed a replication study for discovered single nucleotide polymorphisms (SNPs) with P <10 -6 in 2498 patients with CKD from the Chronic Renal Insufficiency Cohort study. Several expression quantitative trait loci (eQTL) studies, pathway enrichment analyses, exploration of epigenetic architecture, and predicting disruption of transcription factor (TF) binding sites explored potential biological implications of the loci. We developed and evaluated the effect of polygenic risk scores (PRS) on incident CKD outcomes.

RESULTS

SNPs in two novel loci, TPPP and FAT1-LINC02374 , were replicated (rs59402340 in TPPP , Pdiscovery =7.11×10 -7 , PCRIC =8.13×10 -4 , Pmeta =7.23×10 -8 ; rs28629773 in FAT1-LINC02374 , Pdiscovery =6.08×10 -7 , PCRIC =4.33×10 -2 , Pmeta =1.87×10 -7 ). The eQTL studies revealed that the replicated SNPs regulated the expression level of nearby genes associated with kidney function. Furthermore, these SNPs were near gene enhancer regions and predicted to disrupt the binding of TFs. PRS based on the independently significant top 22 SNPs were significantly associated with CKD outcomes.

CONCLUSIONS

This study demonstrates that SNP markers in the TPPP and FAT1-LINC02374 loci could be predictive markers for the decline of eGFR in patients with CKD.

Association of Chronic Kidney Disease With Atrial Fibrillation in the General Adult Population: A Nationwide Population-Based Study

Background The incidences of atrial fibrillation (AF) and chronic kidney disease (CKD) are increasing, and AF is prevalent in patients with CKD. However, few studies have investigated the incidence or association of AF in a large CKD population from a longitudinal study. Methods and Results From a nationwide cohort, a total of 4 827 987 Korean individuals without prior AF, who received biennial health checkups provided by the National Health Insurance Service between 2009 and 2012 in Korea, were analyzed. Incidence of AF was ascertained through the end of 2018. During a median follow-up of 8.1 years, the annual incidence rate of AF was 1.17 per 1000 person-years among subjects without CKD, 1.55 for stage 1 CKD, 1.86 for stage 2 CKD, 2.1 for stage 3 CKD, and 4.33 for stage 4 CKD. In Fine-Gray regression models, CKD was associated with an increased risk of AF; the adjusted hazard ratios and 95% CIs of AF occurrence were 1.77 (1.69-1.85), 1.85 (1.80-1.91), 1.99 (1.95-2.04), and 4.04 (3.07-5.33) in individuals with CKD stages 1, 2, 3, and 4, respectively, compared with non-CKD. The association between CKD and incident AF remained statistically significant after adjustment for multiple confounding factors and was consistent across subgroups stratified by sex and age. Conclusions CKD is associated with an increased incidence of AF. Even mild CKD is associated with incident AF, and there was a stepwise increase in the risk of incident AF with a decrease in renal function.

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.

Comparison of outcomes of chronic kidney disease based on etiology: a prospective cohort study from KNOW-CKD

The causes of chronic kidney disease (CKD) affects its outcomes. However, the relative risks for adverse outcomes according to specific causes of CKD is not well established. In a prospective cohort study from KNOW-CKD, a cohort was analyzed using overlap propensity score weighting methods. Patients were grouped into four categories according to the cause of CKD: glomerulonephritis (GN), diabetic nephropathy (DN), hypertensive nephropathy (HTN), or polycystic kidney disease (PKD). From a total of 2070 patients, the hazard ratio of kidney failure, the composite of cardiovascular disease (CVD) and mortality, and the slope of the estimated glomerular filtration rate (eGFR) decline according to the cause of CKD were compared between causative groups in a pairwise manner. There were 565 cases of kidney failure and 259 cases of composite CVD and death over 6.0 years of follow-up. Patients with PKD had a significantly increased risk for kidney failure compared to those with GN [Hazard ratio (HR) 1.82], HTN (HR 2.23), and DN (HR 1.73). For the composite outcome of CVD and death, the DN group had increased risks compared to the GN (HR 2.07), and HTN (HR 1.73) groups but not to the PKD group. The adjusted annual eGFR change for the DN and PKD groups were - 3.07 and - 3.37 mL/min/1.73 m² per year, respectively, and all of these values were significantly different than those of the GN and HTN groups (- 2.16 and - 1.42 mL/min/1.73 m² per year, respectively). In summary, the risk of kidney disease progression was relatively higher in patients with PKD compared to other causes of CKD. However, the composite of CVD and death was relatively higher in patients with DN-related CKD than in those with GN- and HTN-related CKD.

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.

Identification of Serum Metabolites for Predicting Chronic Kidney Disease Progression according to Chronic Kidney Disease Cause

Early detection and proper management of chronic kidney disease (CKD) can delay progression to end-stage kidney disease. We applied metabolomics to discover novel biomarkers to predict the risk of deterioration in patients with different causes of CKD. We enrolled non-dialytic diabetic nephropathy (DMN, n = 124), hypertensive nephropathy (HTN, n = 118), and polycystic kidney disease (PKD, n = 124) patients from the KNOW-CKD cohort. Within each disease subgroup, subjects were categorized as progressors (P) or non-progressors (NP) based on the median eGFR slope. P and NP pairs were randomly selected after matching for age, sex, and baseline eGFR. Targeted metabolomics was performed to quantify 188 metabolites in the baseline serum samples. We selected ten progression-related biomarkers for DMN and nine biomarkers each for HTN and PKD. Clinical parameters showed good ability to predict DMN (AUC 0.734); however, this tendency was not evident for HTN (AUC 0.659) or PKD (AUC 0.560). Models constructed with selected metabolites and clinical parameters had better ability to predict CKD progression than clinical parameters only. When selected metabolites were used in combination with clinical indicators, random forest prediction models for CKD progression were constructed with AUCs of 0.826, 0.872, and 0.834 for DMN, HTN, and PKD, respectively. Select novel metabolites identified in this study can help identify high-risk CKD patients who may benefit from more aggressive medical treatment.

Associations among body composition parameters and quality of life in peritoneal dialysis patients

Health-related quality of life (HRQOL) is an important issue among patients undergoing dialysis treatment. Peritoneal dialysis (PD) is associated with a number of adverse body composition changes. However, whether body composition is associated with HRQOL is uncertain. The purpose of this study was to analyze the effects of body composition on HRQOL in PD patients. We performed a cross-sectional observational study on the association between body composition and HRQOL in PD patients at a single center. Body composition was determined by multifrequency bioimpedance spectroscopy. HRQOL is summarized to three composite scores: kidney disease component summary (KDCS), physical component summary (PCS), and mental component summary (MCS). The relationships between HRQOL and the hydration index, lean tissue index (LTI), and fat tissue index (FTI) were analyzed by regression analysis. One hundred and ninety-seven PD patients were included in the present study. Patients with severe fluid overload showed a lower PCS. The hydration index and FTI showed statistically significant negative associations with PCS. In subgroup analysis, the associations between the hydration index and PCS remained robust after stratifying according to sex, age, and residual urine. Our results indicated that both the hydration index and FTI were negatively associated with HRQOL, especially PCS.

Comparison of Outcomes of Mild and Severe Community- and Hospital-Acquired Acute Kidney Injury

PURPOSE

Acute kidney injury (AKI) has shown an increasingly common occurrence among hospitalized patients worldwide. We determined the incidence and compared the short- and long-term outcomes of all stages of community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI), and identified predictors for such outcomes.

MATERIALS AND METHODS

This observational, single-center, retrospective study identified patients admitted between January 2013 and December 2013 who developed CA-AKI or HA-AKI. Short- and long-term patient and renal outcomes were analyzed.

RESULTS

AKI incidence was 14.3% (1882, CA-AKI 4.8% and HA-AKI 9.5%). The highest 30-day and 1-year mortality were recorded in the CA-AKI group. Thirty-day mortality rate was 11.4% in CA-AKI group and 5.7% in HA-AKI group (p<0.001). One-year mortality rates were 20.1% and 13.3%, respectively (p<0.001). More CA-AKI patients developed kidney failure with replacement therapy within 1 year (27, 4.3% vs. 18, 1.4% respectively, p<0.001).

CONCLUSION

In conclusion, patients with CA-AKI had worse short- and long-term outcomes compared to HA-AKI patients. AKI severity and discharge serum creatinine were significant independent predictors of 30-day and 1-year mortality.

Insufficient early renal recovery and progression to subsequent chronic kidney disease in living kidney donors

BACKGROUND/AIMS

Renal recovery of a kidney donor after undergoing nephrectomy though challenging is essential. We aimed to examine the effect of estimated glomerular filtration rate (eGFR) percent change at 1-month post-donation on insufficient kidney function after kidney donation.

METHODS

A total of 3,952 living kidney donors who underwent donor nephrectomy from 1982 to 2019 from eight different tertiary hospitals in Korea were initially screened. Percent changes in the eGFR from baseline to 1-month post-donation were calculated. The degree of percent changes was categorized by quartile, and the 1st quartile was regarded as the group with the lowest decreased eGFR at 1-month after donation. The remaining eGFR less than 60 mL/min/1.73 m2 was the end-point. The Cox proportional hazard model was used for evaluating the impact of initial eGFR and eGFR percent change at 1-month post-donation on the condition with remaining eGFR &lt; 60 mL/ min/1.73 m2. In the multivariate analysis, we used variables with a p &lt; 0.1 in the univariate analysis.

RESULTS

A total of 1,585 donors were included in the analysis. During 62.2 ± 49.3 months, 13.7% of donors showed renal insufficiency. The 4th (adjusted hazard ratio [aHR], 10.41; 95% confidence interval [CI], 5.15 to 21.04) and the 3rd (aHR, 4.29; 95% CI, 2.15 to 8.56) quartiles of percent change in eGFR and the pre-donation eGFR (aHR, 0.90; 95% CI, 0.88 to 0.92) were associated with the development of renal insufficiency.

CONCLUSION

The impact of worse initial renal recovery on renal insufficiency was pronounced in donors with lower pre-donation eGFRs. Additionally, worse initial renal recovery of remaining kidney affected the long-term development of renal insufficiency in kidney donors.

Perception regarding live kidney donation in the general population of South Korea

This study aimed to know how the general population recognizes live kidney donation in Korea. Participants were randomly selected from the general population after proportional allocation by region, sex, and age. Selected participants received a questionnaire that included demographic information, socioeconomic and marital statuses, prior recognition of live donor kidney transplantation, expected changes after donation, and the need for support after donor nephrectomy. Among the 1,000 participants from the web-based survey, 83.8% answered they fully understood living donor kidney transplantation, 81.1% knew about them, and 51.1% were willing to donate. Various complications after nephrectomy and deterioration in health after donation were the most significant reasons for those reluctant to donate. Most agreed that the government should provide social and economic support to living kidney donors, especially after exposure to the description of donor nephrectomy. Financial support, including surgery and regular medical check-up costs, was the most preferred government support. The Korean general population seemed aware of the value and safety of kidney donation, although only half of them were willing to donate due to concerns about possible complications. Most participants agreed on social and economic support for living kidney donors, especially surgery-related costs.

Left Ventricular Diastolic Dysfunction and Progression of Chronic Kidney Disease: Analysis of KNOW-CKD Data

Background Few studies have examined the association between the early diastolic mitral inflow velocity/early diastolic mitral annulus velocity ratio (E/e') and chronic kidney disease progression. Methods and Results We reviewed data from 2238 patients with nondialysis chronic kidney disease from the KNOW-CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease); data from 163 patients were excluded because of missing content. A >50% decrease in estimated glomerular filtration rate from baseline, doubling of serum creatinine, or dialysis initiation and/or kidney transplantation were considered renal events. At baseline, median (interquartile range) ejection fraction and E/e' were 64.0% (60.0%-68.0%) and 9.1 (7.4-11.9), respectively. Proportions of ejection fraction <50% and E/e' ≥15 were 1.3% and 9.6%, respectively. More than one quarter of patients (27.2%) had an estimated glomerular filtration rate <30 mL/min per 1.73 m². During the mean 59.1-month follow-up period, 724 patients (34.9%) experienced renal events. In multivariable Cox proportional hazard regression analysis, the hazard ratio with 95% CI per 1-unit increase in E/e' was 1.027 (1.005-1.050; P=0.016). Penalized spline curve analysis yielded a suggested threshold of E/e' for renal events of 12; in our data set, the proportion of E/e' ≥12 was 4.1%. Conclusions Increased E/e' was associated with an increased hazard of renal events, suggesting that diastolic heart dysfunction is a novel risk factor for chronic kidney disease progression.

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).

POS1247 THE EFFECT OF IMMUNOSUPPRESSIVE AGENTS ON ANTIBODY FORMATION AFTER COVID-19 VACCINATION IN RHEUMATOID ARTHRITIS PATIENTS

Background

There is still controversy about the efficacy of COVID-19 vaccination and its extent in lowering immunogenicity of Rheumatoid Arthritis (RA) patients. The guideline in whether immunosuppressive agents need to be discontinued before the vaccination is continuously updated because it is considered to lower immunogenicity. Furthermore, there is great discussion on the effectiveness of the COVID-19 booster vaccine and interest in antibody generation in different types of vaccine, as in South Korea there are many patients who were prescribed the mRNA booster vaccine after two doses of ChAdOx1-S nCoV-19 vaccine.

Objectives

Thus, we investigated the differences of antibody production between patients who received only two doses of ChAdOx1-S nCoV-19 and those who received the mRNA booster vaccine. Also, antibody production under different types of immunosuppressive agents was analyzed.

Methods

From October 14, 2021 to January 21, 2022 at a tertiary referral center, two patient groups diagnosed with RA were studied prospectively; one group that completed 1st and 2nd doses of ChAdOx1-S nCoV-19 vaccine, second group that completed mRNA booster vaccine as well as two doses of ChAdOx1-S nCoV-19 vaccine. SARS-CoV-2 antibody testing on the semiquantitative anti-SARS-CoV-2 S enzyme immunoassay was done, and differences in antibody titers were analyzed in patients who received different immunosuppressive agents such as csDMARD, TNF inhibitor, JAK inhibitor, Tocilizumab, Abatacept and Corticosteroid. Statistical analysis with a multivariate logistic regression model was performed.

Results

In a total of 261 patients, 153 patients had completed two doses of ChAdOx1-S nCoV-19, 108 patients had completed third mRNA booster vaccine. Anti-SARS-CoV-2 RBD antibody positive rate (titer>0.8U/mL) was 97%(149/153) and 99%(107/108) respectively, and only 5 patients showed negative result. In the aspect of high antibody titer(>250U/mL), which is the upper limit of the RBD antibody immunoassay, the result showed rate of 31% (47/153) in the non-booster group and 94%(102/108) in the booster group respectively.

Among the different immunosuppressive agents and other clinical aspects, multivariate analysis revealed that corticosteroid use (OR 0.91; 95% CI: 0.86-0.98), older age(OR 4.33; 95% CI: 1.34-13.91), and male gender(OR 0.35; 95% CI 0.16-0.75) were significantly associated with low rate of high antibody titer.

Furthermore, out of 14 patients who underwent antibody test twice before and after the mRNA booster vaccine, other than four patients who already showed high titer of >250U/mL before the mRNA booster vaccine, 10 patients showed an increase in titer after the booster vaccine and 7 patients were acquired high titer of >250U/mL.

Figure 1.

Anti-SARS-CoV RBD antibody titer of two groups

Table 1.

Analysis of immunosuppressive agents and other clinical aspects for high antibody titer(>250U/mL) after two doses of ChAdOx1-S nCoV-19

Univariate analysisMultivariate analysisParameterOR95% CIp valueOR95% CIp valueClinical features Age0.9170.860-0.9780.0080.9170.857-0.9810.012 Sex3.6741.206-11.1910.0224.3301.348-13.9120.014 DAS 281.1440.670-1.9500.622 Duration0.9300.830-1.0430.214Medications csDMARD1.2730.639-2.5331.273 TNF inhibitor2.2110.795-6.1450.128 JAK inhibitor0.6650.275-1.6070.365 Abatacept0.3680.038-3.6020.391 Tocilizumab1.2640.438-3.6480.665 Corticosteroid0.4720.235-0.9490.0350.3490.163-0.7480.007Medication dose Methotrexate0.9930.919-1.0720.855 Corticosteroid0.8490.719-1.0030.054

Conclusion

Anti-SARS-CoV-2 RBD antibody positive rate was 97% or more regardless of the mRNA booster vaccination. However, patients who received the mRNA booster vaccine after two doses of ChAdOx1-S nCoV-19 vaccine showed high antibody titer (>250U/mL) three times more than those who did not receive the booster shot.

Our findings also showed that corticosteroid use, old age, and male gender is significantly associated with low rate of acquiring high antibody titer.

Disclosure of Interests

None declared

POS0762 LONG-TERM RENAL OUTCOMES OF PATIENTS WITH NON-PROLIFERATIVE LUPUS NEPHRITIS

Background

Although proliferative (class III or IV) lupus nephritis (LN) is the most common finding in the classification of LN, pure membranous (class V) or mesangial (class I or II) LN can occur as a form of LN. Even though non-proliferative LN (class I, II, or V) is a less severe form with good outcomes, data on long-term renal prognosis are limited.

Objectives

This study investigated the long-term outcomes and prognostic factors in non-proliferative LN.

Methods

We retrospectively reviewed the medical records of patients with systemic lupus erythematosus who were diagnosed with LN class I, II, V or II+IV by kidney biopsy between 1997 and 2021 at a tertiary referral center. Clinical and laboratory data were compared between patients with and without poor renal outcomes. Poor renal outcome was defined as an estimated glomerular filtration rate (eGFR) of < 60 mL/min/1.73 m2 or death due to renal cause. Univariate and multivariate analyses were performed with the Cox proportional hazard model to identify the factors associated with poor renal outcomes.

Results

We included 71 patients with non-proliferative LN (4: class I; 17: class II; 48: class V, 17; 2: class II+V). Median follow-up duration was 103 months (interquartile range 27–185) and the overall rate of poor renal outcomes at last follow-up was 29% (21/71), including end-stage renal disease (n=2) and renal death (n=1).

Univariate analysis indicated that older age (HR 1.05; 95% CI: 1.00–1.09), low eGFR (HR 0.97; 95% CI: 0.95–0.99) and failure to reach complete remission at 6 months (HR 0.332; 95% CI: 0.12–0.92) were significantly associated with poor renal outcomes. Multivariate analysis revealed that low eGFR at 6 months (HR 0.97; 95% CI: 0.95–0.99) was significantly associated with poor renal outcomes.

Figure 1.

Renal outcomes at last follow up

eGFR, estimated glomerular filtration rate (ml/min/1.73m2)

Table 1.

Univariate and multivariate Cox proportional hazard regression analyses of the factor associated with poor renal outcomes

ParameterUnivariate analysisMultivariate analysisHR95% CIp valueHR95% CIp valueClinical features Age1.0461.003-1.0910.0361.0020.960-1.0470.921 Sex1.6540.375-7.2980.506 SLEDAI1.0360.965-1.1120.327 Extra renal SLEDAI1.0380.971-1.110.272Renal profiles eGFR at LN diagnosis0.9930.976-1.0110.456 Proteinuria at LN diagnosis1.0001.000-1.0000.444 > 1g/24 hours0.6690.243-1.8410.437  > 3g/24 hours0.6240.229-1.6990.356 eGFR at 6M0.9670.948-0.9860.0010.9680.948-0.9880.002 eGFR at 12M0.9640.947-0.9810.000 Complete remission at 6M0.3320.119-0.9240.0350.5530.179-1.7070.303 Complete remission at 12M0.6670.232-1.9140.451 Transformation1.2460.423-0.7010.692Laboratory data Anti-dsDNA1.0010.999-1.0030.196 C31.0201.000-1.0410.051 C41.0270.969-1.0890.367 Albumin1.1800.661-2.1090.576ClassificationaClass I0.8020.102-6.3030.834Class II1.2980.412-4.0880.656Class V0.8870.308-2.5570.824Class II+V0.0480.000-16850.837Medicationsb ACEi/ARB1.6520.603-4.5280.329 Hydroxychloroquine1.3260.414-4.2420.635 Corticosteroid1.1860.154-9.1080.870 CNI2.4390.464-12.8240.292 MMF3.7880.959-14.9650.057  　 AZA0.5890.133-2.6110.486

a LN classifications were based on the International Society of Pathology/Renal Pathology Society (ISN/RPS) classification.

b Medications maintained at least one year since Lupus Nephritis diagnosis.

HR, hazard ratio; 95% CI, 95% confidence interval; SLEDAI, systemic lupus erythematosus disease activity index; eGFR, estimated glomerular filtration rate; LN, lupus nephritis; anti-dsDNA, anti-double strand DNA; C3/C4; complement 3/4; ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; CNI, carcineurin inhibitor; MMF, mycophenolate mofetil; AZA, azathioprine.

Conclusion

Poor renal outcomes occurred in approximately 30% of patients with non-proliferative LN (class I, II or V) after long-term follow-up.

Our findings suggest that more active management may be needed for non-proliferative LN, particularly in patients with low eGFR at 6 months.

Disclosure of Interests

None declared

Past the Precipice? Projected Coral Habitability Under Global Heating

Coral reefs are rapidly declining due to local environmental degradation and global climate change. In particular, corals are vulnerable to ocean heating. Anomalously hot sea surface temperatures (SSTs) create conditions for severe bleaching or direct thermal death. We use SST observations and CMIP6 model SST to project thermal conditions at reef locations at a resolution of 1 km, a 16-fold improvement over prior studies, under four climate emissions scenarios. We use a novel statistical downscaling method which is significantly more skillful than the standard method, especially at near-coastal pixels where many reefs are found. For each location we present projections of thermal departure (TD, the date after which a location with steadily increasing heat exceeds a given thermal metric) for severe bleaching recurs every 5 years (TD5Y) and every 10 years (TD10Y), accounting for a range of post-bleaching reef recovery/degradation. As of 2021, we find that over 91% and 79% of 1 km² reefs have exceeded TD10Y and TD5Y, respectively, suggesting that widespread long-term coral degradation is no longer avoidable. We project 99% of 1 km² reefs to exceed TD5Y by 2034, 2036, and 2040 under SSP5-8.5, SSP3-7.0, and SSP2-4.5 respectively. We project that 2%-5% of reef locations remain below TD5Y at 1.5°C of mean global heating, but 0% remain at 2.0°C. These results demonstrate the importance of further improving ecological projection capacity for climate-vulnerable marine and terrestrial species and ecosystems, including identifying refugia and guiding conservation efforts. Ultimately, saving coral reefs will require rapidly reducing and eliminating greenhouse gas emissions.

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).

Long-term risk of all-cause mortality in live kidney donors: a matched cohort study

Background

Long-term outcomes of live kidney donors remain controversial, although this information is crucial for selecting potential donors. Thus, this study compared the long-term risk of all-cause mortality between live kidney donors and healthy control.

Methods

We performed a retrospective cohort study including donors from seven tertiary hospitals in South Korea. Persons who underwent voluntary health screening were included as controls. We created a matched control group considering age, sex, era, body mass index, baseline hypertension, diabetes, estimated glomerular filtration rate, and dipstick albuminuria. The study outcome was progression to end-stage kidney disease (ESKD), and all-cause mortality as identified in the linked claims database.

Results

We screened 1,878 kidney donors and 78,115 health screening examinees from 2003 to 2016. After matching, 1,701 persons remained in each group. The median age of the matched study subjects was 44 years, and 46.6% were male. Among the study subjects, 2.7% and 16.6% had underlying diabetes and hypertension, respectively. There were no ESKD events in the matched donor and control groups. There were 24 (1.4%) and 12 mortality cases (0.7%) in the matched donor and control groups, respectively. In the age-sex adjusted model, the risk for all-cause mortality was significantly higher in the donor group than in the control group. However, the significance was not retained after socioeconomic status was included as a covariate (adjusted hazard ratio, 1.82; 95% confidence interval, 0.87-3.80).

Conclusion

All-cause mortality was similar in live kidney donors and matched non-donor healthy controls with similar health status and socioeconomic status in the Korean population.

Metabolic risks in living kidney donors in South Korea

Background

Considering the growing prevalence of Western lifestyles and related chronic diseases occurring in South Korea, this study aimed to explore the progression of metabolic risk factors in living kidney donors.

Methods

This study enrolled living kidney donors from seven hospitals from 1982 to 2016. The controls were individuals that voluntarily received health check-ups from 1995 to 2016 that were matched with donors according to age, sex, diabetes status, baseline estimated glomerular filtration rate, and date of the medical record. Data on hyperuricemia, hypertension, hypercholesterolemia, and overweight/obesity were collected to determine metabolic risks. Logistic regressions with interaction terms between the medical record date and donor status were used to compare the trends in metabolic risks over time in the two groups.

Results

A total of 2,018 living kidney donors and matched non-donors were included. The median age was 44.0 years and 54.0% were women. The living kidney donors showed a lower absolute prevalence for all metabolic risk factors, except for those that were overweight/obese, than the non-donors. The proportion of subjects that were overweight/obese was consistently higher over time in the donor group. The changes over time in the prevalence of each metabolic risk were not significantly different between groups, except for a lower prevalence of metabolic risk factors ≥ 3 in donors.

Conclusion

Over time, metabolic risks in living kidney donors are generally the same as in non-donors, except for a lower prevalence of metabolic risk factors ≥3 in donors.

Effect of negative-pressure wound therapy on wound complications in obese women after caesarean birth: a systematic review and meta-analysis

BACKGROUND

Obesity is associated with increased surgical-site infection (SSI) following caesarean section (CS).

OBJECTIVE

To summarise the evidence on the effectiveness of negative-pressure wound therapy (NPWT) for preventing SSI and other wound complications in obese women after CS.

SEARCH STRATEGY

MEDLINE, Embase, CINAHL, Cochrane CENTRAL databases and ClinicalTrials.gov were systematically searched in March 2021.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of NPWT compared with standard dressings after CS birth.

DATA COLLECTION AND ANALYSIS

Pooled effect sizes were calculated using either fixed or random effects models based on heterogeneity. The Cochrane risk of bias and Grading of Recommendations Assessment, Development and Evaluation tools were used to assess the quality of studies and overall quality of evidence.

MAIN RESULTS

Ten RCTs with 5583 patients were included; studies were published between 2012 and 2021. Nine RCTs with 5529 patients were pooled for the outcome SSI. Meta-analysis results suggest a significant difference favouring the NPWT group (relative risk [RR] 0.79, 95% CI 0.65-0.95, P < 0.01), indicating an absolute risk reduction of 1.8% among those receiving NPWT compared with usual care. The risk of blistering in the NPWT group was significantly higher (RR 4.13, 95% CI 1.53-11.18, P = 0.005). All studies had high risk of bias relative to blinding of personnel/participants. Only 40% of studies reported blinding of outcome assessments and 50% had incomplete outcome data.

CONCLUSIONS

The decision to use NPWT should be considered both in terms of its potential benefits and its limitations.

TWEETABLE ABSTRACT

NPWT was associated with fewer SSI in women following CS birth but was not effective in reducing other wound complications.

Greater adherence to the dietary approaches to stop hypertension dietary pattern is associated with preserved muscle strength in patients with autosomal dominant polycystic kidney disease: a single-center cross-sectional study

The present study aimed to determine whether certain diets lower the risk of low muscle strength in patients with autosomal dominant polycystic kidney disease (ADPKD). In this cross-sectional study, outpatient ADPKD patients were enrolled from a tertiary care hospital. Muscle strength was assessed on the basis of handgrip strength (HGS), and dietary pattern indices were calculated using dietary intake data. Among the 68 participants included in this study, 19 (27.9%) had low HGS. Cystatin C concentrations were significantly higher in all participants, and in women in the low compared to the normal HGS group in the unadjusted analyses (P = 0.004). Among analyzed dietary pattern indices, the Dietary Approaches to Stop Hypertension (DASH) score was lower, for all participants and men, in the low compared to the normal HGS group (P < 0.05). Especially, the component score for whole grains of the DASH score was significantly lower in men in the low compared to the normal HGS group in unadjusted analyses. The DASH score was positively correlated with HGS in men (r = 0.387, P = 0.046). In addition, logistic regression analysis showed that the DASH score was negatively associated with low HGS, for all participants (odds ratio = 0.851, P = 0.049) and men (odds ratio = 0.716, P = 0.043), after adjusting for age, sex, and body weight. These findings suggest that the DASH dietary pattern may promote the preservation of muscle strength in ADPKD patients. The DASH diet can be considered as a nutritional strategy to maintain muscle strength and prevent sarcopenia in ADPKD patients.

Economic Impact of Donating a Kidney on Living Donors: A Korean Cohort Study

RATIONALE & OBJECTIVE

Although existing studies have reported adverse health outcomes after kidney donation, its socioeconomic impact on living donors requires further study.

STUDY DESIGN

A retrospective observational cohort study including a matched comparison group.

SETTING & PARTICIPANTS

1,285 living kidney donors from 7 tertiary hospitals between 2003 and 2016, and a matched comparison group consisting of the same number of health screening examinees with similar baseline clinical characteristics and socioeconomic status. All participants were receiving Korean national health insurance.

EXPOSURE

Kidney donation as reflected in the Korean National Health Insurance System (NHIS) database.

OUTCOME

Changes in household economic status estimated by Korean national health insurance fees and changes in employment status reflected in the NHIS database.

ANALYTICAL APPROACH

The outcomes of the donor group and matched control group were compared annually using multivariable logistic regression analyses adjusted for clinical and demographic characteristics.

RESULTS

The median ages of the donors and matched controls were 45 and 46 years, respectively; 44.6% of both groups were male. Compared to the comparison group, living donors were at higher risk of being unemployed or losing employment during the first 2 years after donation (eg, first-year loss of employment: odds ratio (OR), 2.27 [95% CI, 1.55-3.33]); however, this association did not persist. Donors also had a significantly lower odds of improvement in economic status (OR, 0.57 [95% CI, 0.47-0.71]) and a higher odds of deterioration in financial status (OR, 1.54 [95% CI, 1.23-1.93]) in the first year after transplantation and subsequently.

LIMITATIONS

Unmeasured differences between donors and matched controls creating residual selection bias and confounding.

CONCLUSIONS

Living kidney donors may suffer loss of employment and poor economic status after their voluntary donation. The socioeconomic impact on these donors should be considered in conjunction with the potential long-term adverse health outcomes after donation.

Identification of a novel inhibitor of liver cancer cell invasion and proliferation through regulation of Akt and Twist1

When primary cancer faces limited oxygen and nutrient supply, it undergoes an epithelial–mesenchymal transition, which increases cancer cell motility and invasiveness. The migratory and invasive cancer cells often exert aggressive cancer development or even cancer metastasis. In this study, we investigated a novel compound, 3-acetyl-5,8-dichloro-2-((2,4-dichlorophenyl)amino)quinolin-4(1H)-one (ADQ), that showed significant suppression of wound healing and cellular invasion. This compound also inhibited anchorage-independent cell growth, multicellular tumor spheroid survival/invasion, and metalloprotease activities. The anti-proliferative effects of ADQ were mediated by inhibition of the Akt pathway. In addition, ADQ reduced the expression of mesenchymal markers of cancer cells, which was associated with the suppressed expression of Twist1. In conclusion, ADQ successfully suppressed carcinogenic activity by inhibiting the Akt signaling pathway and Twist1, which suggests that ADQ may be an efficient candidate for cancer drug development.

Antioxidant and Anti-Inflammatory Effects of Bischofia javanica (Blume) Leaf Methanol Extracts through the Regulation of Nrf2 and TAK1

Bischofia javanica (Blume) has been traditionally used to treat inflammatory diseases such as tonsillitis and ulcers throughout Asia, including China, Indonesia, and the Philippines: however, the molecular mechanisms by which B. javanica exerts its antioxidant and anti-inflammatory properties remain largely unknown. In this study, we analyzed the antioxidant and anti-inflammatory mechanisms of methanol extracts of B. javanica leaves (MBJ) in vitro and in vivo. MBJ decreased nitric oxide (NO) production and the expression of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, in lipopolysaccharide (LPS)-treated RAW 264.7 cells. The observed suppression of inflammatory responses by MBJ was correlated with an inhibition of the nuclear factor-κB (NF-κB) and the mitogen-activated protein kinase (MAPK) pathways. Additionally, MBJ induced nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that upregulates the expression of anti-inflammatory and antioxidant genes. Furthermore, MBJ exhibited antioxidant and anti-inflammatory effects in an acute hepatitis mouse model. In conclusion, our results confirm the medicinal properties of B. javanica, and therefore MBJ could be applied to improve inflammatory and redox imbalances in different types of pathologies.

Metabolic Acidosis Is an Independent Risk Factor of Renal Progression in Korean Chronic Kidney Disease Patients: The KNOW-CKD Study Results

Background: We aimed to evaluate serum bicarbonate as a risk factor for renal progression, cardiovascular events, and mortality in Korean CKD patients.

Methods: We analyzed 1,808 participants from a Korean CKD cohort whose serum bicarbonate levels were measured at enrollment. Serum bicarbonate levels were categorized as low, lower normal, higher normal, and high (total carbon dioxide <22, 22–26, 26.1–29.9, and ≥30 mmol/L, respectively) groups. Metabolic acidosis was defined as a serum bicarbonate level <22 mmol/L. The primary outcome was renal events defined as doubling of serum creatinine, 50% reduction of eGFR from the baseline values, or development of end-stage kidney disease. The secondary outcome consisted of cardiovascular events and death. In addition, patients whose eGFR values were measured more than three times during the follow-up period were analyzed for eGFR decline. The rapid decline in eGFR was defined as lower than the median value of the eGFR slope.

Results: The mean serum bicarbonate level was 25.7 ± 3.7 mmol/L and 240 (13.2%) patients had metabolic acidosis. During the follow-up period of 55.2 ± 24.1 months, 545 (30.9%) patients developed renal events and 187 (10.6%) patients developed a composite of cardiovascular events and death. After adjustment, the low serum bicarbonate group experienced 1.27 times more renal events than the lower normal bicarbonate group [hazard ratio (HR): 1.27; 95% CI: 1.01–1.60, P = 0.043]. There was no significant association between the bicarbonate groups and the composite outcome of cardiovascular events and death. The low bicarbonate group showed a significantly rapid decline in eGFR [odds ratio (OR): 2.12; 95% CI: 1.39–3.22, P < 0.001] compared to the lower normal bicarbonate group.

Conclusions: Metabolic acidosis was significantly associated with increased renal events and a rapid decline in renal function in Korean predialysis CKD patients.

Serum uric acid is associated with coronary artery calcification in early chronic kidney disease: a cross-sectional study

Background

Although uric acid (UA) is regarded as a risk factor for cardiovascular disease, whether UA is an independent risk factor contributing to coronary artery calcification in chronic kidney disease (CKD) is not well known. We evaluated whether UA level is associated with coronary artery calcium (CAC) score in a predialysis CKD cohort.

Methods

A total of 1,350 subjects who underwent coronary computed tomography as part of the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease were analysed. We conducted a logistic regression analysis to evaluate the association between UA and the presence of CAC.

Results

CAC was detected in 705 (52.2 %) patients, and the level of UA was significantly higher in CAC > 0 patients. UA showed a positive relationship with CAC > 0 in age- and sex-adjusted logistic regression analysis (Odds ratio (OR) 1.11, 95 % confidence interval (CI) 1.04–1.19, P = 0.003). However, UA showed no association with CAC > 0 in multivariate analysis. Further analysis showed that UA showed a positive association with CAC > 0 only in estimated glomerual filtration rate (eGFR) > 60 ml/min/1.73 m² (OR 1.23, 95 % CI 1.02–1.49, P = 0.036) but not in eGFR 30–59 ml/min/1.73 m² (OR 0.92, 95 % CI 0.78–1.08, P = 0.309) or < 30 ml/min/1.73 m² (OR 0.92, 95 % CI 0.79–1.08, P = 0.426).

Conclusions

UA level was significantly associated with CAC in early CKD, but not in advanced CKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02463-2.

Evolving outcomes of peritoneal dialysis: secular trends at a single large center over three decades

Background

Peritoneal dialysis (PD) is improving as a renal replacement therapy for end-stage renal disease (ESRD) patients. We analyzed the main outcomes of PD over the last three decades at a single large-scale PD center with an established high-quality care system.

Methods

As a retrospective cohort study, we included participants (n = 1,203) who began PD between 1990 and 2019. Major PD-related outcomes were compared among the three 10-year cohorts.

Results

The 1,203 participants were 58.3% male with a mean age of 47.9 ± 13.8 years. The median PD treatment duration was 45 months (interquartile range, 19–77 months); 362 patients (30.1%) transferred to hemodialysis, 289 (24.0%) received kidney transplants, and 224 (18.6%) died. Overall, the 5- and 8-year adjust patient survival rates were 64% and 49%, respectively. Common causes of death included infection (n = 55), cardiac (n = 38), and cerebrovascular (n = 17) events. The 5- and 8-year technique survival rates were 77% and 62%, respectively, with common causes of technique failure being infection (42.3%) and solute/water clearance problems (22.7%). The 5-year patient survival significantly improved over time (64% for the 1990–1999 cohort vs. 93% for the 2010–2019 cohort). The peritonitis rate also substantially decreased over time, from 0.278 episodes/patient-year (2000–2004) to 0.162 episodes/patient-year (2015–2019).

Conclusion

PD is an effective treatment option for ESRD patients. There was a substantial improvement in the patient survival and peritonitis rates over time. Establishing adequate infrastructure and an effective system for high-quality PD therapy may be warranted to improve PD outcomes.

Measured sodium excretion is associated with CKD progression: results from the KNOW-CKD study

BACKGROUND

Diet is a modifiable factor of chronic kidney disease (CKD) progression. However, the effect of dietary salt intake on CKD progression remains unclear. Therefore, we analyzed the effect of dietary salt intake on renal outcome in Korean patients with CKD.

METHODS

We measured 24-h urinary sodium (Na) excretion as a marker of dietary salt intake in the prospective, multi-center, longitudinal KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD). Data were analyzed from CKD patients at Stages G3a to G5 (n = 1254). We investigated the association between dietary salt intake and CKD progression. Patients were divided into four quartiles of dietary salt intake, which was assessed using measured 24-h urinary Na excretion. The study endpoint was composite renal outcome, which was defined as either halving the estimated glomerular filtration rate or developing end-stage renal disease.

RESULTS

During a median (interquartile range) follow-up of 4.3 (2.8-5.8) years, 480 (38.7%) patients developed the composite renal event. Compared with the reference group (Q2, urinary Na excretion: 104.2 ≤ Na excretion < 145.1 mEq/day), the highest quartile of measured 24-h urinary Na excretion was associated with risk of composite renal outcome [Q4, urinary Na excretion ≥192.9 mEq/day, hazard ratio 1.8 (95% confidence interval 1.12-2.88); P = 0.015] in a multivariable hazards model. Subgroup analyses showed that high-salt intake was particularly associated with a higher risk of composite renal outcome in women, in patients <60 years of age, in those with uncontrolled hypertension and in those with obesity.

CONCLUSIONS

High salt intake was associated with increased risk of progression in CKD.

Optomechanical crystals for spatial sensing of submicron sized particles

Optomechanical crystal cavities (OMC) have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, bacteria and viruses. In this work we demonstrate the working principle of OMCs operating under ambient conditions as a sensor of submicrometer particles by optically monitoring the frequency shift of thermally activated mechanical modes. The resonator has been specifically designed so that the cavity region supports a particular family of low modal-volume mechanical modes, commonly known as -pinch modes-. These involve the oscillation of only a couple of adjacent cavity cells that are relatively insensitive to perturbations in other parts of the resonator. The eigenfrequency of these modes decreases as the deformation is localized closer to the centre of the resonator. Thus, by identifying specific modes that undergo a frequency shift that amply exceeds the mechanical linewidth, it is possible to infer if there are particles deposited on the resonator, how many are there and their approximate position within the cavity region. OMCs have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, viruses and bacteria.