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Background Limited data exist on the association between gut permeability, circulating bacterial fragment and volume overload in peritoneal dialysis (PD) patients. We measured circulating bacterial fragments, N-terminal pro B-type natriuretic peptide (NT-proBNP), calprotectin and zonulin levels, and evaluate their association with the clinical outcomes in PD patients. Methods This was a single-center prospective study on 108 consecutive incident PD patients. Plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels were measured. Primary outcomes were technique and patient survival, secondary outcomes were hospitalization data. Results There was no significant correlation between plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels. The Homeostatic Model Assessment for Insulin Resistance (HOMA)-2β index, which represents insulin resistance, positively correlated with plasma bacterial DNA (r = 0.421, P  < .001) and calprotectin levels (r = 0.362, P  = .003), while serum NT-proBNP level correlated with the severity of volume overload and residual renal function. Serum NT-proBNP level was associated with technique survival even after adjusting for confounding factors [adjusted hazard ratio (aHR) 1.030, 95% confidence interval 1.009–1.051]. NT-proBNP level was also associated with patient survival by univariate analysis, but the association became insignificant after adjusting for confounding factors (aHR 1.010, P  = .073). Similarly, NT-proBNP correlated with the number of hospitalizations and duration of hospitalization by univariate analysis, but the association became insignificant after adjusting for confounding factors. Conclusion There was no correlation between markers of gut permeability, circulating bacterial fragments and measures of congestion in PD patients. Bacterial fragments levels and gut permeability are both associated with insulin resistance. Serum NT-proBNP level is associated with the severity of volume overload and technique survival. Further studies are required to delineate the mechanism of high circulating bacterial fragment levels in PD patients. [ABSTRACT FROM AUTHOR]

Background: Renal glycogen synthase kinase-3 beta (GSK3β) overactivity has been associated with a diverse range of kidney diseases. GSK3β activity in urinary exfoliated cells was reported to predict the progression of diabetic kidney disease (DKD). We compared the prognostic value of urinary and intrarenal GSK3β levels in DKD and nondiabetic chronic kidney disease (CKD). Methods: We recruited 118 consecutive biopsy-proved DKD patients and 115 nondiabetic CKD patients. Their urinary and intrarenal GSK3β levels were measured. They were then followed for dialysis-free survival and rate of renal function decline. Results: DKD group had higher intrarenal and urinary GSK3β levels than nondiabetic CKD (p < 0.0001 for both), but their urinary GSK3β mRNA levels were similar. Urinary p-GSK3β level is statistically significantly correlated with the baseline estimated glomerular filtration rate (eGFR), but urinary GSK3β level by ELISA, its mRNA level, the p-GSK3β level, or the p-GSK3β/GSK3β ratio had no association with dialysis-free survival or the slope of eGFR decline. In contrast, the intrarenal pY216-GSK3β/total GSK3β ratio significantly correlated with the slope of eGFR decline (r = −0.335, p = 0.006) and remained an independent predictor after adjusting for other clinical factors. Conclusion: Intrarenal and urinary GSK3β levels were increased in DKD. The intrarenal pY216-GSK3β/total GSK3β ratio was associated with the rate of progression of DKD. The pathophysiological roles of GSK3β in kidney diseases deserve further studies. [ABSTRACT FROM AUTHOR]

Background Peritoneal dialysis (PD) is a home-based renal replacement therapy. Since hospital staff are not often familiar with PD and its complications, PD patients may have an excess risk of developing PD-related peritonitis during hospital admission for unrelated reasons, and the outcome may be affected. Methods We reviewed 371 episodes of hospital-acquired PD peritonitis in our center from 2000 to 2019. Their clinical characteristics and outcomes were compared with 825 episodes that required hospital admission and 1964 episodes that were treated as outpatient. Results Hospitalized PD patients had a significantly higher risk of developing peritonitis than outpatients [incident rate ratio 4.41 (95% confidence interval 3.95–4.91]. Hospital-acquired peritonitis episodes were more commonly culture negative. Bacterial isolates from the hospital-acquired episodes were more likely resistant to ceftazidime (P < .0001) than the other groups. The primary response rate, complete cure rate and overall mortality of the hospital-acquired episodes were 66.6%, 62.0%, and 23.2%, respectively, all worse than episodes that developed outside the hospital (P < .0001 for all). Conclusion PD patients admitted to the hospital had a 4-fold increase in the risk of developing peritonitis. Hospital-acquired peritonitis episodes were more likely culture negative and resistant to antibiotics. They also had a lower primary response rate, a lower complete cure rate and higher mortality than episodes that developed outside the hospital. [ABSTRACT FROM AUTHOR]

• Previous studies showed that urinary levels of some miRNA targets are significantly altered in IgA nephropathy. • The persent study used healthy subjects and patients with biopsy-proved hypertensive nephrosclerosis as controls, so as to eliminate the confounding effect of kidney scarring. • The result showed that urinary miR-106a has good sensitivity but limited specificity in detecting IgA nephropathy. • Our result indicates that urinary miRNA level may be used for screening of IgA nephropathy. Urinary micro-RNA (miRNA) level may serve as non-invasive disease markers for immunoglobulin A nephropathy (IgAN), but urinary miRNA targets identified in previous studies may represent kidney scarring rather than being specific for IgAN. We aim to identify urinary miRNA targets for the diagnosis of IgAN by including hypertensive nephrosclerosis (HTN) as a control group. Methods In the development cohort, we performed complete miRNA profiling of urinary sediment in 33 patients with IgAN, 9 with HTN, and 9 healthy controls (CTL). Potential miRNA targets were quantified by a separate validation cohort of 72 IgAN, 34 HTN, and 20 healthy controls. Results In the development cohort, we identified 6 miRNA targets with urinary levels significantly increased in IgAN as compared to both HTN and CTL. In the validation study, all 6 miRNA targets remained increased than the other groups, although the result of miR-345 did not reach statistical significance. The area-under-curve of the receiver operating characteristic (ROC) curve for urinary mi-106a level for the diagnosis of IgAN was 0.742 (p < 0.0001), and the diagnostic performance was not further improved by having additional miRNA targets. At the cut-off ≥ 800 copy per 1000 copies of housekeeping gene, urinary miR-106a has 100% sensitivity and 14.8% specificity in detecting IgA nephropathy. Conclusions We identified 6 miRNA targets whose urinary levels are significantly elevated in IgAN, and urinary miR-106a level has an excellent sensitivity for the identification of IgAN. Further validation studies are needed to confirm its role in disease screening. [ABSTRACT FROM AUTHOR]

Background The global prevalence of both obesity and end-stage kidney diseases (ESKDs) has increased in recent decades. Given the complicated interaction between obesity and ESKD, we examined the change in the prevalence of obesity in incident Chinese peritoneal dialysis (PD) patients over the past 25 years. Methods We reviewed the anthropometric measures of incident PD patients in a single Hong Kong center from 1995 to 2019. The results are reported in five 5-year periods. Patients with and without diabetes were analyzed separately, and the incidence of new-onset diabetes after PD was explored. Results We reviewed 1681 patients. Their mean age was 58.4 ± 12.5 years; 931 patients (55.4%) had pre-existing diabetes. From 1995–99 to 2015–19, the prevalence of obesity or overweight at the initiation of PD increased progressively for every 5-year period (from 21.9% to 26.2, 37.9, 42.7 and 47.3%, P < 0.001 for linearity). The increase in the prevalence of obesity or overweight was more pronounced in diabetic patients (from 33.7% to 59.6%) than non-diabetic ones (from 13.2% to 32.3%). Among nondiabetics patients, the incidence of new-onset diabetes after started on PD showed an insignificant rising trend during that period (from 18.0, 19.7, 17.8 and 22.4% to 23.3%, P = 0.106). The incidence of new-onset impaired fasting glucose or diabetes was significantly higher in obese or overweight patients than the others (56.9% versus 51.4%, P < 0.001). Conclusions The prevalence of obesity has increased substantially in both diabetic and nondiabetic new PD patients in Hong Kong over the past 25 years. The incidence of new-onset diabetes was significantly higher in new PD patients with pre-existing obesity or overweight than those without obesity. The prognostic implication and impacts on the healthcare system deserve further studies. [ABSTRACT FROM AUTHOR]

• Mitochondrial DNA (mtDNA) resembles bacterial DNA and potentially triggers local and systemic inflammation. • We found that serum C-reactive protein level closely with PDE sediment mtDNA level and less with supernatant mtDNA level. • PDE supernatant mtDNA level correlated with peritoneal transport. • PDE sediment mtDNA level significantly correlated with systemic inflammation. • PDE sediment mtDNA level also independently predicted technique survival and duration of hospitalization. • The mechanism of the different implications between PDE sediment and supernatant mtDNA levels deserves further investigations. Mitochondrial DNA (mtDNA) resembles bacterial DNA and potentially triggers local and systemic inflammation. We evaluate the prognostic implications of PD effluent mtDNA level in peritoneal dialysis (PD) patients. We measured mtDNA in the PD effluent (PDE) sediment and supernatant of 168 incident PD patients. All patients were followed for hospitalization, technique and overall survival. The median PD effluent supernatant and sediment mtDNA levels were 255.4 unit (interquartile range [IQR] 157.5–451.3) and 201.6 unit (IQR 147.8–267.3), respectively. Serum C-reactive protein level closely with PDE sediment mtDNA level (r = 0.471, p < 0.001) and less with supernatant mtDNA level (r = 0.156, p = 0.044). PDE supernatant mtDNA level correlates with dialysate-to-plasma creatinine ratio at 4 h (D/P4) (r = 0.361, p < 0.001) but not with any clinical outcome. PDE sediment mtDNA was an independent predictor of technique survival (p = 0.011) and the duration of hospitalization (p = 0.044) after adjusting for clinical confounding factors. PDE sediment mtDNA level significantly correlated with systemic inflammation, while PDE supernatant mtDNA level correlated with peritoneal transport. PDE sediment mtDNA level also independently predicted technique survival and duration of hospitalization. The mechanism of the different implications between PDE sediment and supernatant mtDNA levels deserves further investigations. [ABSTRACT FROM AUTHOR]

Background: Physical frailty contributes to adverse clinical outcomes in peritoneal dialysis (PD) patients. Little has been reported about frailty transitions in this population. We aimed to describe the transitions of frailty in PD patients and identify factors that predicted changes in frailty state. Methods: In a prospective observational study, we recruited 267 PD patients. Frailty was assessed by a validated frailty score. Depression was graded by PHQ-9 score, and nutritional status was evaluated by serum albumin, Subjective Global Assessment (SGA), and comprehensive Malnutrition Inflammation Score (MIS). The primary outcome was the change in frailty score at follow-up compared to baseline. Results: At baseline, 194 (72.7%) patients were classified as frail. With time, their frailty scores significantly increased (p < 0.001), and 93 of the surviving subjects (78.2%) were classified as frail. There was a modest significant correlation between change in MIS (p < 0.001), change in SGA score (p < 0.001), and change in PHQ-9 score (p < 0.001) with change in frailty score. An increase in PHQ-9 score (p < 0.001) and MIS (p = 0.001), as well as longer duration of hospitalization (p = 0.001), was independently associated with a greater change in frailty score after adjustment for confounding factors. Frailty score was also improved in patients who were converted to hemodialysis (p = 0.048) and received renal transplantation (p = 0.005). Conclusion: Our findings suggested that frailty transitions were common in PD patients. Worsening in nutrition and depression, together with a longer duration of hospitalization, were associated with worsening in frailty. [ABSTRACT FROM AUTHOR]

Background Dialysate sodium (DNa) prescription policy differs between haemodialysis (HD) units, and the optimal DNa remains uncertain. We sought to summarize the evidence on the agreement between prescribed and delivered DNa, and whether the relationship varied according to prescribed DNa. Methods We searched MEDLINE and PubMed from inception to 26 February 2020 for studies reporting measured and prescribed DNa. We analysed results reported in aggregate with random-effects meta-analysis. We analysed results reported by individual sample, using mixed-effects Bland–Altman analysis and linear regression. Pre-specified subgroup analyses included method of sodium measurement, dialysis machine manufacturer and proportioning method. Results Seven studies, representing 908 dialysate samples from 10 HD facilities (range 16–133 samples), were identified. All but one were single-centre studies. Studies were of low to moderate quality. Overall, there was no statistically significant difference between measured and prescribed DNa {mean difference = 0.73 mmol/L [95% confidence interval (CI) −1.12 to 2.58; P = 0.44]} but variability across studies was substantial (I 2 = 99.3%). Among individually reported samples (n  = 295), measured DNa was higher than prescribed DNa by 1.96 mmol/L (95% CI 0.23–3.69) and the 95% limits of agreement ranged from −3.97 to 7.88 mmol/L. Regression analysis confirmed a strong relationship between prescribed and measured DNa, with a slope close to 1:1 (β  = 1.16, 95% CI 1.06–1.27; P < 0.0001). Conclusions A limited number of studies suggest that, on average, prescribed and measured DNa are similar. However, between- and within-study differences were large. Further consideration of the precision of delivered DNa is required to inform rational prescribing. [ABSTRACT FROM AUTHOR]

Background Relapsing and recurrent peritonitis episodes are major causes of technique failure in peritoneal dialysis (PD). We examined the efficacy of extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis. Methods From February 2016 to November 2018 we recruited 254 PD patients who fulfilled the diagnostic criteria for PD peritonitis. They were randomized to a standard group, with the duration of intraperitoneal (IP) antibiotic treatment following the International Society for Peritoneal Dialysis (ISPD) guideline according to the causative microorganisms, and an extended group, with 1 extra week of IP antibiotics. The primary endpoint was relapsing, recurrent or repeat peritonitis episodes within 6 months. Results The primary endpoint developed in 36 and 29 patients of the extended and standard groups, respectively (28.3% versus 22.8%; P = 0.34). The rate of complete cure, without relapsing, recurrent or repeat peritonitis within 6 months, was 63.8 and 69.3% for the extended and standard groups, respectively (P = 0.35). Repeat peritonitis episodes were more common in the extended than the standard group (15.0% versus 5.5%; P = 0.013). Conclusions In patients with PD-related peritonitis, extending the antibiotic therapy for 1 extra week beyond the ISPD protocol should not be recommended. Extending the treatment does not reduce the risk of relapsing or recurrent peritonitis episodes but rather is associated with a higher risk of repeat peritonitis episodes. [ABSTRACT FROM AUTHOR]

Background: Endocan is associated with endothelial dysfunction. In peritoneal dialysis (PD) patients, cardiovascular disease is a common cause of mortality. We examined the relationship between serum endocan level and clinical outcome of PD patients. Methods: We recruited 193 new PD patients (118 males, mean age 58.8 ± 11.6 years). Serum endocan levels were determined and stratified into tertile 1 (lowest) to 3 (highest). Nutritional status, arterial pulse wave velocity (PWV) and serum C-reactive protein (CRP) levels were measured. The patients were followed for at least 4 years for clinical outcomes. Results: For the whole cohort, patients with higher serum endocan levels had lower serum albumin and subjective global assessment score, higher carotid-femoral PWV, and higher serum CRP. For patients with suboptimal blood pressure (BP) control, cardiovascular event-free survival was 95.0, 95.5, and 78.5% for tertiles 1, 2, and 3 at 60 months respectively (p = 0.019). Multivariate Cox regression analysis showed that serum endocan level was an independent predictor of cardiovascular event-free survival. No association with cardiovascular event-free survival was found for patients with adequate BP control (95.0, 92.3, and 100% for tertile 1, 2, and 3 at 60 months, respectively, p = 0.6). Conclusions: Higher serum endocan level is associated with unfavourable nutritional, arterial and inflammatory conditions in PD patients. In patients with suboptimal BP control, higher serum endocan is also associated with worse cardiovascular outcome. [ABSTRACT FROM AUTHOR]

Background: Fluid overload is common among asymptomatic peritoneal dialysis (PD) patients. We aim to determine the prevalence and prognostic significance of fluid overload, as measured by bioimpedance spectroscopy, in asymptomatic incident PD patients. Methods: We performed a single-center study on 311 incident PD patients. Volume status was represented by the volume of overhydration (OH), OH/extracellular water (ECW) ratio, ECW/total body water (TBW) ratio, and ECW to intracellular water (ICW) ratio (E:I ratio). Patient survival, technique survival and cardiovascular event-free survival were determined. Results: The median period of follow up was 27.3 months. Fluid overload was present in 272 patients (87.5%) when defined as OH volume over 1.1L. All hydration parameters significantly correlated with Charlson Comorbidity Index, and inversely with total Kt/V, and serum albumin. Multivariate cause-specific Cox analysis showed that volume status independently predicted patient survival; every 0.1 unit increase in E:I ratio was associated with 24.5% increase in all-cause mortality (adjusted cause-specific hazard ratio [ACSHR] 1.245, p = 0.002). Hydration status was also an independent predictor of cardiovascular event-free survival after excluding hospital admission for congestive heart failure; each 0.1 unit increase in E:I ratio was associated with 18.7% decrease in cardiovascular event-free survival (ACSHR 1.187, p = 0.011). In contrast, hydration parameters were not associated with technique survival. Conclusions: Fluid overload is common in asymptomatic incident PD patients and is a strong predictor of patient survival and cardiovascular event. The impact of bioimpedance spectroscopy-guided fluid management on the outcome of PD patients deserves further study. [ABSTRACT FROM AUTHOR]

Background/Aims: Enterococcal peritonitis in peritoneal dialysis (PD) patients is associated with a high complication rate. The optimal treatment regimen of PD-related enterococcal peritonitis is controversial. The latest international guideline recommends intra-peritoneal (IP) vancomycin. Although ampicillin is often effective for systemic enterococcal infections, they have little in vitro activity when added to common PD solutions. Since oral amoxicillin achieves therapeutic drug level in the peritoneal cavity, we explore the efficacy of oral amoxicillin for enterococcal peritonitis. Methods: We studied 105 episodes of enterococcal peritonitis over 20 years in our unit; 43 (41.0%) were treated with oral amoxicillin, and 62 (59.0%) with IP vancomycin. Their clinical outcome was reviewed. Result: The overall primary response rate to oral amoxicillin and IP vancomycin was 76.4% and 85.5%, respectively (p = 0.3). The complete cure rate of oral amoxicillin and IP vancomycin was 55.8% and 54.8%, respectively (p = 0.8). When the 5 episodes of ampicillin-resistant Enterococcus episodes were excluded, the primary response rate and complete cure rate of oral amoxicillin were 86.8% and 63.2%, respectively. Conclusion: Oral amoxicillin has an excellent primary response rate and complete cure rate for PD-related peritonitis episodes caused by Enterococcus species, indicating that oral amoxicillin is a valid and convenient therapeutic option for enterococcal peritonitis episodes. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Family members of patients with end-stage renal disease (ESRD) have higher risk for chronic kidney disease (CKD). Limited study has examined the risk of developing CKD in relatives of patients in earlier stages of CKD. Methods From January 2008 to June 2009, the Hong Kong Society of Nephrology studied first-degree relatives of stage 1-5 CKD patients from 11 local hospitals. A total of 844 relatives of 466 index CKD patients (stages 1-2: 29.6%; stage 3: 16.7%; stage 4: 10.9%; stage 5: 42.7%) were reviewed for various risk factors of CKD. We also defined a composite marker of kidney damage by the presence of one or more following features: (i) positive urine protein, (ii) spot urine protein-to-creatinine ratio ≥0.15 mg/mg, (iii) hypertension and (iv) estimated glomerular filtration rate (eGFR) ≤60 mL/min per 1.73 m2 and determine its association with participant and index patient factors. Results Among these 844 relatives, 23.1%, 25.9% and 4.4% of them had proteinuria (urine protein ≥1+), haematuria (urine red blood cell ≥1+) and glycosuria (urine glucose ≥1+), respectively. Proteinuria ( P = 0.10) or glycosuria ( P = 0.43), however, was not associated with stages of CKD of index patients. Smoking participants had a significantly lower eGFR (102.7 vs. 107.1 mL/min per 1.73 m2) and a higher prevalence of proteinuria (33.6% vs. 21.4%). Multivariate analysis showed that older age, male gender, obesity, being parents of index patients and being the relatives of a female index patient were independently associated with a positive composite marker. Conclusion First-degree relatives of all stages of CKD are at risk of developing CKD and deserve screening. Parents, the elderly, obese and male relatives were more likely to develop markers of kidney damage. [ABSTRACT FROM AUTHOR]

There were limited data on the efficacy and safety profile on use of sodium–glucose co-transporter 2 receptor (SGLT2) inhibitors in diabetic patients with advanced chronic kidney disease (CKD). We aimed to evaluate the efficacy, in terms of improvement in glycemic profile, kidney function, prevention of adverse kidney and cardiovascular events, and the safety profile of SGLT2 inhibitors in a group of diabetic patients at CKD stage 3B-5 from a real-world population-based cohort. We performed a retrospective observational cohort study of type 2 diabetic patients at CKD stage 3B-5 who received SGLT2 inhibitors as compared to control from 1 January 2015 through 31 December 2021. Propensity score assignment by logistic regression and matching with control by the nearest score at 1:3 ratio was done. All patients were followed for 1 year. Outcomes were kidney-related adverse events and major adverse cardiovascular events (MACE), change in estimated glomerular filtration rate (eGFR), glycemic control, and side effects profiling. We analyzed 1,450 SGLT2 inhibitor users. They had significantly lower rates of kidney-related adverse events (7.7 % versus 24.1 %, p < 0.001) and MACE (9.6 % versus 15.1 %, p < 0.001) as compared to control group. Their eGFR also significantly improved (0.4 ± 9.3 versus −5.5 ± 10.6 ml/min/1.73 m2, p < 0.001). These patients also had a greater reduction in HbA1c (-0.40 ± 1.13 versus -0.04 ± 1.47 %, p < 0.001), and insulin requirement (-8.8 ± 35.2 versus 4.1 ± 19.4 units/day, p < 0.001). After adjusting for confounders, SGLT2 inhibitors protected against kidney-related adverse events (odds ratio [OR] 0.48, 95 % confidence interval [CI] 0.33 – 0.71, p < 0.001) and MACE (OR 0.47, 95 % CI 0.37 – 0.60, p < 0.001). Apart from a marginally higher rate of fungal urinary tract infection (0.08 ± 0.66 versus 0.03 ± 0.23 episodes per year, p < 0.001), SGLT2 inhibitor use was not associated with other side effects. SGLT2 inhibitor improved kidney function, glycemic profile, and reduced adverse kidney-related and cardiovascular events in diabetic patients with advanced CKD. [ABSTRACT FROM AUTHOR]

Background/Aims: Previous studies showed that frailty is prevalent in both pre-dialysis and dialysis patients. However, the prevalence and prognostic implication of frailty in Chinese peritoneal dialysis (PD) patients remain unknown. Methods: We used a validated questionnaire to determine the Frailty Score of 193 unselected prevalent PD patients. All patients were then followed for 2 years for their need of hospitalization and mortality. Results: Amongst the 193 patients, 134 (69.4%) met the criteria of being frail. Frailty Score significantly correlated with Charlson's comorbidity score (r = 0.40, p < 0.0001), Malnutrition Inflammation Score (r = 0.59, p < 0.0001), and inversely with Subjective Global Assessment score (r = -0.44, p < 0.0001). Frailty was closely associated with the need of hospitalization. Patients with nil, mild, moderate, and severe frailty required 2.4 ± 6.0, 1.6 ± 1.6, 2.7 ± 2.5, 5.2 ± 4.8 hospital admissions per year, respectively (p < 0.0001), and they stayed in hospital for 6.4 ± 9.2, 5.3 ± 6.2, 10.0 ± 10.4, 12.9 ± 20.1 days per hospital admission, respectively (p < 0.0001). However, Frailty Score was not an independent predictor of patient or technique survival. Conclusions: Frailty is prevalent among Chinese PD patients. Frail PD patients have a high risk of requiring hospitalization and their hospital stay tends to be prolonged. Early identification may allow timely intervention to prevent adverse health outcomes in this group of patients. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The reported causes of nephrotic syndrome (NS) varies between different countries. Less is known about the causes of nephrotic‐range proteinuria (NPU). We aimed to evaluate the underlying causes of NS and NPU. Methods: This was a single‐centre, retrospective study of adult patients who underwent renal biopsy between 1983 and 2015 in a tertiary referral hospital in Hong Kong. We determined the distribution of histopathological diagnoses with regard to the age subgroups and time periods. Results: Among 7456 patients who underwent renal biopsy, 982 and 838 patients had NS and NPU, respectively. The most common diagnosis in NS was minimal change disease (MCD) (33.3%), followed by membranous nephropathy (MN) (23.6%) and lupus nephritis (LN) (12.8%); whereas the most common diagnosis in NPU was LN (27.4%), followed by immunoglobulin A nephropathy (IgAN) (21.4%) and diabetic nephropathy (DN) (9.3%). In the NS group, MCD was the most common diagnosis in young adults while MN was the leading cause in the elderly. On the other hand, LN was the most common pathology in the NPU group until the age of 60. Over the past three decades, there was a trend of decrease in the proportion of IgAN in both NS and NPU group, while a combined pathology of hypertensive nephrosclerosis and diabetic nephropathy (HTNS and DN) increased significantly. Conclusions: The causes of NS and NPU in Chinese adults were different and may represent two distinct pathological identities. The spectrum of renal histopathology among these two groups changed significantly over time. [ABSTRACT FROM AUTHOR]

The role of intra-peritoneal mediators in the regulation peritoneal transport is not completely understood. We investigate the relation between longitudinal changes in dialysis effluent level of nuclear factor kappa-B (NF-κB) downstream mediators and the change in peritoneal transport over 1 year. We studied 46 incident PD patients. Their peritoneal transport characteristics were determined after starting PD and then one year later. Concomitant dialysis effluent levels of interleukin-6 (IL-6), cyclo-oxygenase-2 (COX-2) and hepatocyte growth factor (HGF) are determined. There were significant correlations between baseline and one-year dialysis effluent IL-6 and COX-2 levels with the corresponding dialysate-to-plasma creatinine level at 4 hours (D/P4) and mass transfer area coefficient of creatinine (MTAC). After one year, patients who had peritonitis had higher dialysis effluent IL-6 (26.6 ± 17.4 vs 15.1 ± 12.3 pg/ml, p = 0.037) and COX-2 levels (4.97 ± 6.25 vs 1.60 ± 1.53 ng/ml, p = 0.007) than those without peritonitis, and the number of peritonitis episode significantly correlated with the IL-6 and COX-2 levels after one year. In contrast, dialysis effluent HGF level did not correlate with peritoneal transport. There was no difference in any mediator level between patients receiving conventional and low glucose degradation product solutions. Dialysis effluent IL-6 and COX-2 levels correlate with the concomitant D/P4 and MTAC of creatinine. IL-6 and COX-2 may contribute to the short-term regulation of peritoneal transport. [ABSTRACT FROM AUTHOR]

Background: Emerging evidence suggests that long non-coding RNA (lncRNA) plays important roles in the regulation of gene expression. We determine the role of using urinary lncRNA as a non-invasive biomarker for lupus nephritis. Method: We studied three cohorts of lupus nephritis patients (31, 78, and 12 patients, respectively) and controls (6, 7, and 24 subjects, respectively). The urinary sediment levels of specific lncRNA targets were studied using real-time quantitative polymerase chain reactions. Results: The severity of proteinuria inversely correlated with urinary maternally expressed gene 3 (MEG3) (r = −0.423, p = 0.018) and ANRIL levels (r = −0.483, p = 0.008). Urinary MEG3 level also inversely correlated with the SLEDAI score (r = −0.383, p = 0.034). Urinary cancer susceptibility candidate 2 (CASC2) levels were significantly different between histological classes of nephritis (p = 0.026) and patients with pure class V nephritis probably had the highest levels, while urinary metastasis-associated lung carcinoma transcript 1 (MALAT1) level significantly correlated with the histological activity index (r = −0.321, p = 0.004). Urinary taurine-upregulated gene 1 (TUG1) level was significantly lower in pure class V lupus nephritis than primary membranous nephropathy (p = 0.003) and minimal change nephropathy (p = 0.04), and urinary TUG1 level correlated with eGFR in class V lupus nephritis (r = 0.706, p = 0.01). Conclusions: We identified certain urinary lncRNA targets that may help the identification of lupus nephritis and predict the histological class of nephritis. Our findings indicate that urinary lncRNA levels may be developed as biomarkers for lupus nephritis. [ABSTRACT FROM AUTHOR]

ABSTRACT To address the issue of heavy dialysis burden due to the rising prevalence of end-stage renal disease around the world, a roundtable discussion on the sustainability of managing dialysis burden around the world was held in Hong Kong during the First International Congress of Chinese Nephrologists in December 2015. The roundtable discussion was attended by experts from Hong Kong, China, Canada, England, Malaysia, Singapore, Taiwan and United States. Potential solutions to cope with the heavy burden on dialysis include the prevention and retardation of the progression of CKD; wider use of home-based dialysis therapy, particularly PD; promotion of kidney transplantation; and the use of renal palliative care service. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) is a major cause of mortality and morbidity in peritoneal dialysis (PD) patients. Two decades ago, the common co‐existence of malnutrition and systemic inflammation PD patients with atherosclerosis and CVD led to the proposed terminology of 'malnutrition‐inflammation‐atherosclerosis (MIA) syndrome'. Although the importance of malnutrition is well accepted, frailty represents a more comprehensive assessment of the physical and functional capability of the patient and encompasses the contributions of sarcopenia (a key component of malnutrition), obesity, cardiopulmonary as well as neuropsychiatric impairment. In recent years, it is also increasingly recognized that fluid overload is not only the consequence but also play an important role in the pathogenesis of CVD. Moreover, fluid overload is closely linked with the systemic inflammatory status, presumably by gut oedema, gastrointestinal epithelial barrier dysfunction and leakage of bacterial fragments to the systemic circulation. There are now a wealth of published evidence to show intricate relations between frailty, inflammation, fluid overload and atherosclerotic disease in patients with chronic kidney disease (CKD) and those on PD, a phenomenon that we propose the term 'FIFA complex'. In this system, frailty and atherosclerotic disease may be regarded as two patient‐oriented outcomes, while inflammation and fluid overload are two inter‐connected pathogenic processes. However, there remain limited data on how the treatment of one component affect the others. It is also important to define how treatment of fluid overload affect the systemic inflammatory status and to develop effective anti‐inflammatory strategies that could alleviate atherosclerotic disease and frailty. Summary at a Glance: There are intricate relations between frailty, inflammation, fluid overload and atherosclerotic disease in patients with chronic kidney disease (CKD) and those on peritoneal dialysis (PD).We propose the term 'FIFA complex', with frailty and atherosclerotic disease as two patient‐oriented outcomes, while inflammation and fluid overload as two inter‐connected pathogenic processes. [ABSTRACT FROM AUTHOR]

Background: Dysnatraemias are commonly reported in COVID-19. However, the clinical epidemiology of hypernatraemia and its impact on clinical outcomes in relation to different variants of SARS-CoV-2, especially the prevailing Omicron variant, remain unclear. Methods: This was a territory-wide retrospective study to investigate the clinical epidemiology and outcomes of COVID-19 patients with hypernatraemia at presentation during the period from 1 January 2020 to 31 March 2022. The primary outcome was 30-day mortality. Key secondary outcomes included rates of hospitalization and ICU admission, and costs of hospitalization. Results: In this study, 53,415 adult COVID-19 patients were included for analysis. Hypernatraemia was observed in 2688 (5.0%) patients at presentation, of which most cases (99.2%) occurred during the local "5th wave" dominated by the Omicron BA.2 variant. Risk factors for hypernatraemia at presentation included age, institutionalization, congestive heart failure, dementia, higher SARS-CoV-2 Ct value, white cell count, C-reactive protein and lower eGFR and albumin levels (p < 0.001 for all). Patients with hypernatraemia showed significantly higher 30-day mortality (32.0% vs. 5.7%, p < 0.001) and longer lengths of stay (12.9 ± 10.9 vs. 11.5 ± 12.1 days, p < 0.001) compared with those with normonatraemia. Multivariate analysis revealed hypernatraemia at presentation as an independent predictor for 30-day mortality (aHR 1.32, 95% CI 1.14–1.53, p < 0.001) and prolonged hospital stays (OR 1.55, 95% CI 1.17–2.05, p = 0.002). Conclusions: Hypernatraemia is common among COVID-19 patients, especially among institutionalized older adults with cognitive impairment and other comorbidities during large-scale outbreaks during the Omicron era. Hypernatraemia is associated with unfavourable outcomes and increased healthcare utilization. [ABSTRACT FROM AUTHOR]

Background There are limited data on the association of adipose microRNA expression with body composition and adverse clinical outcomes in patients with advanced chronic kidney disease (CKD). We aimed to evaluate the association of adipose miR-130b and miR-17-5p expressions with body composition, functional state, cardiovascular outcome and mortality in incident dialysis patients. Methods We performed a single-center prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. miR-130b and miR-17-5p expressions were measured from subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and physical function were assessed by bioimpedance spectroscopy and Clinical Frailty Scale. Primary outcome was 2-year survival. Secondary outcomes were 2-year technique survival and major adverse cardiovascular event (MACE) rate. Results Adipose expression of miR-130b and miR-17-5p correlated with parameters of muscle mass including intracellular water (miR-130b: r = 0.191, P = 0.02; miR-17-5p: r = 0.211, P = 0.013) and lean tissue mass (miR-17-5p: r = 0.176, P = 0.04; miR-17-5p: r = 0.176, P = 0.004). miR-130b expression predicted frailty significantly (P = 0.017). Adipose miR-17-5p expression predicted 2-year all-cause survival (P = 0.020) and technique survival (P = 0.036), while miR-130b expression predicted incidence of MACE (P = 0.015). Conclusions Adipose miR-130b and miR-17-5p expressions correlated with body composition parameters, frailty, and predicted cardiovascular events and mortality in advanced CKD patients. [ABSTRACT FROM AUTHOR]

There were limited data on adipose and serum zinc alpha-2-glycoprotein (ZAG) expression and its association with body composition in patients with advanced chronic kidney disease (CKD). This study aimed to quantify adipose and serum ZAG expression and evaluate their association with body composition and its longitudinal change, together with mortality in incident dialysis patients. We performed a single-center prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. ZAG levels were measured from serum sample, subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and functional state were evaluated by bioimpedance spectroscopy and Clinical Frailty Scale respectively at baseline and were repeated 1 year later. Primary outcome was 2-year survival. Secondary outcomes were longitudinal changes of body composition. At baseline, the average adipose and serum ZAG expression was 13.4 ± 130.0-fold and 74.7 ± 20.9 µg/ml respectively. Both adipose and serum ZAG expressions independently predicted adipose tissue mass (ATM) (p = 0.001, p = 0.008, respectively). At 1 year, ATM increased by 3.3 ± 7.4 kg (p < 0.001) while lean tissue mass (LTM) remained similar (p = 0.5). Adipose but not serum ZAG level predicted change in ATM (p = 0.007) and LTM (p = 0.01). Serum ZAG level predicted overall survival (p = 0.005) and risk of infection-related death (p = 0.045) after adjusting for confounders. In conclusion, adipose and serum ZAG levels negatively correlated with adiposity and predicted its longitudinal change of fat and lean tissue mass, whilst serum ZAG predicted survival independent of body mass in advanced CKD patient. [ABSTRACT FROM AUTHOR]

Hyperglycemia causes mitochondrial damage renal tubular cells, which contribute to the progression of diabetic kidney disease. However, the metabolic aberration of renal tubular cells in an hyperglycemic milieu has not been fully elucidated. In this study, human proximal renal tubular cell line (HK-2 cell) are incubated in glucose and mannitol at 5 mM or 25 mM. Cellular metabolome was determined by capillary electrophoresis time of flight mass spectrometer (CE-TOF/MS) and capillary electrophoresis-triple quadrupole mass spectrometry (CE-QqQMS). A total of 116 metabolites were quantified. Principal component analysis (PCA) revealed excellent clustering of metabolomic changes for different treatment conditions, and exposure to glucose at 5 and 25 mM lead to distinct metabolomic profiles as compared to samples treated with serum-free medium or mannitol as osmotic control. Hierarchical clustering analysis showed a number of characteristic changes in metabolic profile following exposure to 5 mM or 25 mM glucose. Notably, lactate-to-pyruvate ratio was significantly increased, while cellular levels of citric acid, α-ketoglutaric acid (i.e. 2-oxoglutaric acid), and fumaric acid were significantly reduced after exposure to glucose at 25 mM but not 5 mM. Moreover, cellular levels of reduced glutathione and total glutathione were significantly decreased, and S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH) ratio was significantly increased after exposure to glucose 25 mM but not 5 mM. We conclude that in response to high glucose, HK-2 cells characteristic metabolomic changes, including increase in lactate-to-pyruvate ratio, reduction in Krebs cycle metabolites, reduction in glutathione antioxidant activity, and increase in cellular methylation potential. Our results may shed light on the pathogenesis of diabetic kidney disease, but the expression of glucose metabolism-related protein and enzyme activity in HK-2 cells after hyperglycemia condition need to be confirmed by further studies. [ABSTRACT FROM AUTHOR]

Background: Several comorbidity scoring systems have been developed and validated, mostly in western hemodialysis patients with a high risk of cardiovascular disease. The performance of comorbidity scoring, however, depends on the patient population. In this study, we determine the optimal comorbidity scoring system for predicting survival of incident Chinese PD patients.Methods: We studied 461 incident PD patients. The performance of Charlson Comorbidity Index (CCI), Hemmelgarn score, and Liu score as the survival predictor was compared.Results: The mean age was 57.7 ± 13.7 years. The median CCI, Hemmelgarn, and Liu scores were 4 [inter-quartile range (IQR) 2–5], 1 (IQR 0–2), and 4 (IQR 2–5), respectively. Patients were followed for 45.5 ± 33.0 months. All 3 comorbidity scores were predictors of patient survival by univariate analysis. After adjusting for confounding factors, CCI was the best predictor of patient survival among the 3 indices, with each point increase in CCI conferring 31% excess in mortality risk [95% confidence interval (CI) 21–41%, p < 0.001]. In contrast, each point increase in Liu score confers 20% excess in mortality risk (95% CI 13–27%, p < 0.001). Although the Hemmelgarn score is an independent predictor of patient survival, over 70% of patients score 0 or 1 by this system, limiting its role as a prognostic marker.Conclusion: CCI should be the preferred method for quantifying comorbidity load in incident Chinese PD patients, and it is a good predictor of survival in this group of patients. [ABSTRACT FROM AUTHOR]

Background The role of microRNA (miRNA) in peritoneal fibrosis and longitudinal change in transport is uncertain. Methods We studied 80 new peritoneal dialysis (PD) patients. Peritoneal transport was determined by standard peritoneal equilibration test (PET) of creatinine at baseline. Based on published literature, PD effluent levels of 10 miRNA targets were quantified. PET and miRNA quantification were repeated one year later in 46 patients. Results Baseline PD effluent levels of all targets tested had modest but significant correlation with peritoneal transport parameters. PD effluent miR-21 and miR-589 levels correlated with dialysate-to-plasma creatinine concentration at 4 h (D/P4) at baseline (r = 0.377, p = 0.001 and r = 0.237, p = 0.037, respectively) and after one year of PD (r = 0.362, p = 0.014 and r = 0.402, p = 0.007). The change in PD effluent − 21 and miR-589 levels over one year correlated with the corresponding change in D/P4 (r = 0.470, p = 0.001 and r = 0.479, p = 0.002). The number of peritonitis episodes during follow up significantly correlated with the change in PD effluent miR-21 (r = 0.387, p = 0.009) and miR-589 (r = 0.336, p = 0.027) levels. There was no significant correlation between PD effluent miRNA level and ultrafiltration volume. Conclusion Amongst the 10 miRNA targets tested, miR-21 and miR-589 showed consistently significant relation with peritoneal transport. Further studies are needed to delineate their mechanisms of regulating peritoneal transport. [ABSTRACT FROM AUTHOR]

Background: Circulating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that plasma bacterial DNA level predicts cardiovascular events in new PD patients. Methods: We measured plasma bacterial DNA level in 191 new PD patients, who were then followed for at least a year for the development of cardiovascular event, hospitalization, and patient survival. Results: The average age was 59.3 ± 11.8 years; plasma bacterial DNA level 34.9 ± 1.5 cycles; average follow up 23.2 ± 9.7 months. At 24 months, the event-free survival was 86.1%, 69.8%, 55.4% and 30.8% for plasma bacterial DNA level quartiles I, II, III and IV, respectively (p < 0.0001). After adjusting for confounders, plasma bacterial DNA level, baseline residual renal function and malnutrition-inflammation score were independent predictors of composite cardiovascular end-point; each doubling in plasma bacterial DNA level confers a 26.9% (95% confidence interval, 13.0 – 42.5%) excess in risk. Plasma bacterial DNA also correlated with the number of hospital admission (r = -0.379, p < 0.0001) and duration of hospitalization for cardiovascular reasons (r = -0.386, p < 0.0001). Plasma bacterial DNA level did not correlate with baseline arterial pulse wave velocity (PWV), but with the change in carotid-radial PWV in one year (r = -0.238, p = 0.005). Conclusions: Circulating bacterial DNA fragment level is a strong predictor of cardiovascular event, need of hospitalization, as well as the progressive change in arterial stiffness in new PD patients. [ABSTRACT FROM AUTHOR]