Cost-Effectiveness of School Urinary Screening for Early Detection of IgA Nephropathy in Japan.

Importance: The evidence for and against screening for chronic kidney disease in youths who are asymptomatic is inconsistent worldwide. Japan has been conducting urinary screening in students for 50 years, allowing for a full economic evaluation that includes the clinical benefits of early detection and intervention for chronic kidney disease. Objectives: To evaluate the clinical effectiveness and cost-effectiveness of school urinary screening in Japan, with a focus on the benefits of the early detection and intervention for IgA nephropathy, and to explore key points in the model that are associated with the cost-effectiveness of the school urinary screening program. Design, Setting, and Participants: This economic evaluation with a cost-effectiveness analysis used a computer-simulated Markov model from the health care payer's perspective among a hypothetical cohort of 1 000 000 youths aged 6 years in first grade in Japanese elementary schools, followed up through junior and high school. The time horizon was lifetime. Costs and clinical outcomes were discounted at a rate of 2% per year. Costs were calculated in Japanese yen and 2020 US dollars (¥107 = US $1). Interventions: School urinary screening for IgA nephropathy was compared with no screening. Main Outcomes and Measures: Outcomes were costs and quality-adjusted life-years (QALYs). Cost-effectiveness was determined by evaluating whether the incremental cost-effectiveness ratio (ICER) per QALY gained remained less than ¥7 500 000 (US $70 093). Results: In the base case analysis, the ICER was ¥4 186 642 (US $39 127)/QALY, which was less than the threshold. There were 60.3 patients/1 000 000 patients in the no-screening strategy and 31.7 patients/1 000 000 patients in the screening strategy with an end-stage kidney disease. Cost-effectiveness improved as the number of screenings decreased (screening frequency <3 times: incremental cost, -¥75 [US $0.7]; incremental QALY, 0.00025; ICER, dominant), but the number of patients with end-stage kidney disease due to IgA nephropathy increased (40.9 patients/1 000 000 patients). Assuming the disutility due to false positives had a significant impact on the analysis; assuming a disutility of 0.01 or more, the population with no IgA nephropathy had an ICER greater than the threshold (¥8 304 093 [US $77 608]/QALY). Conclusions and Relevance: This study found that Japanese school urinary screening was cost-effective, suggesting that it may be worthy of resource allocation. Key factors associated with cost-effectiveness were screening cost, the probability of incident detection outside of screening, and IgA nephropathy incidence, which may provide clues to decision-makers in other countries when evaluating the program in their own context.

Current clinical practice in adapted automated peritoneal dialysis (aAPD)-A prospective, non-interventional study.

Adapted automated peritoneal dialysis (aAPD), comprising a sequence of dwells with different durations and fill volumes, has been shown to enhance both ultrafiltration and solute clearance compared to standard peritoneal dialysis with constant time and volume dwells. The aim of this non-interventional study was to describe the different prescription patterns used in aAPD in clinical practice and to observe outcomes characterizing volume status, dialysis efficiency, and residual renal function over 1 year. Prevalent and incident, adult aAPD patients were recruited during routine clinic visits, and aAPD prescription, volume status, residual renal function and laboratory data were documented at baseline and every quarter thereafter for 1 year. Treatments were prescribed according to the nephrologist's medical judgement in accordance with each center's clinical routine. Of 180 recruited patients, 160 were analyzed. 27 different aAPD prescription patterns were identified. 79 patients (49.4%) received 2 small, short dwells followed by 3 long, large dwells. During follow-up, volume status changed only marginally, with visit mean values ranging between 1.59 (95% confidence interval: 1.19; 1.99) and 1.97 (1.33; 2.61) L. Urine output and creatinine clearance decreased significantly, accompanied by reductions in ultrafiltration and Kt/V. 25 patients (15.6%) received a renal transplant and 15 (9.4%) were changed to hemodialysis. Options for individualization offered by aAPD are actually used in practice for optimized treatment. Changes observed in renal function and dialysis efficiency measures reflect the natural course of chronic kidney disease. No safety events were observed during the study period.

Urinary mRNA Signatures as Predictors of Renal Function Decline in Patients With Biopsy-Proven Diabetic Kidney Disease.

The clinical manifestations of diabetic kidney disease (DKD) are more heterogeneous than those previously reported, and these observations mandate the need for the recruitment of patients with biopsy-proven DKD in biomarker research. In this study, using the public gene expression omnibus (GEO) repository, we aimed to identify urinary mRNA biomarkers that can predict histological severity and disease progression in patients with DKD in whom the diagnosis and histologic grade has been confirmed by kidney biopsy. We identified 30 DKD-specific mRNA candidates based on the analysis of the GEO datasets. Among these, there were significant alterations in the urinary levels of 17 mRNAs in patients with DKD, compared with healthy controls. Four urinary mRNAs-LYZ, C3, FKBP5, and G6PC-reflected tubulointerstitial inflammation and fibrosis in kidney biopsy and could predict rapid progression to end-stage kidney disease independently of the baseline eGFR (tertile 1 vs. tertile 3; adjusted hazard ratio of 9.68 and 95% confidence interval of 2.85-32.87, p < 0.001). In conclusion, we demonstrated that urinary mRNA signatures have a potential to indicate the pathologic status and predict adverse renal outcomes in patients with DKD.

The ratio of measured to estimated glomerular filtration rate may be a marker of early mortality and dialysis requirement.

BACKGROUND: It has been suggested that, in patients with CKD stage 5, measured GFR (mGFR), defined as the mean of urea and creatinine clearance, as measured by a 24-h urine collection, is a better measure of renal function than estimated GFR (eGFR), based on the CKD-EPI formula. This could be due to reduced muscle mass in this group. Its use is recommended in the ERBP guidelines. Unplanned dialysis initiation (DI) is associated with increased morbidity, mortality, and reduced modality choice and is generally considered undesirable. We hypothesized that the ratio mGFR/eGFR (M/E) aids prediction of death and DI. METHODS: All 24-h measurements of urea and creatinine excretion were extracted from the clinical biochemistry databases in Zealand. Data concerning renal diagnosis, comorbidity, biochemistry, medical treatment, mortality and date of DI, were extracted from patient notes, the National Patient Registry and the Danish Nephrology Registry. Patients were included if their eGFR was < 30 ml/min/1.73m2. The last available value for each patient was included. Follow-up was 12 months. RESULTS: One thousand two hundred sixty-five patients were included. M/E was median 0.91 ± 0.43. It was highly correlated to previous determinations. It was negatively correlated to eGFR, comorbidity, high age and female sex. It was positively related to albumin and negatively to C-reactive protein. M/E was higher in patients treated with ACE inhibitors and diuretics but no other treatment groups. On a multivariate analysis, M/E was negatively correlated with mortality and combined mortality/DI, but not DI. A post hoc analysis showed a negative correlation to DI at 3 months. For patients with an eGFR 10-15 ml/min/1.73m2, combined mortality and DI at 3 months was for low M/E (< 0.75) 36%, medium (0.75-1.25) 20%, high (> 1.25) 8%. A low M/E predicted increased need for unplanned DI. A supplementary analysis in 519 patients where body surface area values were available, allowing BSA-corrected M/E to be analyzed, revealed similar results. CONCLUSION: A low mGFR/eGFR ratio is associated with comorbidity, malnutrition, and inflammation. It is a marker of early DI, mortality, and unplanned dialysis initiation, independently of eGFR, age and comorbidity. Particular attention paid to patients with a low M/E may lower the incidence of unplanned dialysis requirement.

Primary IgA nephropathy with nephrotic-range proteinuria in Chinese children.

ABSTRACT: To investigate the clinicopathological features and outcomes of primary IgA nephropathy with nephrotic-range proteinuria in Chinese children. Patients with biopsy-proven IgA nephropathy and nephrotic-range proteinuria between January 2011 and December 2017 were included, and their proteinuria and renal function were followed up. A total of 90 patients were enrolled, and 21.1% (19/90) of them had decreased renal function at diagnosis. Complete remission, partial remission, and no response of proteinuria occurred in 88.6% (70/79), 10.1% (8/79), and 1.3% (1/79), respectively, of the 79 patients who were followed up for 6 to 104 months. 73.7% (14/19) of the patients with decreased renal function at diagnosis recovered to normal level while 26.3% (5/19) of them did not recover or progressed to end-stage renal disease. Two patients with normal renal function at diagnosis progressed to renal insufficiency during follow-up period. By multivariate analysis, the risk for renal function deterioration was significantly higher in the partial remission and no response groups than in the complete remission group. Remission of proteinuria was important for improving renal prognosis in children with IgA nephropathy and nephrotic-range proteinuria. The outcomes for pediatric patients appeared to be better than that reported in adults.

A Scoring Model with Simple Clinical Parameters to Predict Successful Discontinuation of Continuous Renal Replacement Therapy.

BACKGROUND: Continuous renal replacement therapy (CRRT) is the standard treatment for severe acute kidney injury in critically ill patients. However, a practical consensus for discontinuing CRRT is lacking. We aimed to develop a prediction model with simple clinical parameters for successful discontinuation of CRRT. METHODS: Adult patients who received CRRT at Samsung Medical Center from 2007 to 2017 were included. Patients with preexisting ESRD and patients who progressed to ESRD within 1 year or died within 7 days after CRRT were excluded. Successful discontinuation of CRRT was defined as no requirement for renal replacement therapy for 7 days after discontinuing CRRT. Patients were assigned to either a success group or failure group according to whether discontinuation of CRRT was successful or not. RESULTS: A total of 1,158 patients were included in the final analyses. The success group showed greater urine output on the day before CRRT discontinuation (D-1) and the discontinuation day (D0). Multivariable analysis identified that urine output ≥300 mL on D-1, and mean arterial pressure 50∼78 mm Hg, serum potassium <4.1 mmol/L, and BUN <35 mg/dL (12.5 mmol/L) on D0 were predictive factors for successful discontinuation of CRRT. A scoring system using the 4 variables above (area under the receiver operating curve: 0.731) was developed. CONCLUSIONS: Scoring system composed of urine output ≥300 mL/day on D-1, and adequate blood pressure, serum potassium <4.1 mmol/L, and BUN <35 mg/dL (12.5 mmol/L) on D0 was developed to predict successful discontinuation of CRRT.

Evaluation of Residual Kidney Function during Once-Weekly Incremental Hemodialysis.

BACKGROUND: The initial once-weekly administration of incremental hemodialysis to patients with residual kidney function (RKF) has recently attracted considerable interest. METHODS: The aim of our study was to assess the performance of a series of different methods in measuring serum urea nitrogen and serum Cr (sCr) RKF in patients on once-weekly hemodialysis (1WHD). Evaluations were carried out by means of 24-h predialysis urine collection (Kr-24H) or 6-day inter-dialysis collection (Kr-IDI) and estimation of glomerular filtration rate based on (KrSUN + KrsCr)/2 for the purpose of identifying a simple reference calculation to be used in assessing RKF in patients on 1WHD dialysis. Ninety-five urine samples were collected from 12 1WHD patients. A solute solver urea and Cr kinetic modeling program was used to calculate residual urea and Cr clearances. Mann-Whitney U test, Pearson's correlation coefficient (R), and linear determination coefficient (R2) were used for statistical analysis. RESULTS: 1WHD patients displayed a mean KrSUN-IDI of 4.5 ± 1.2 mL/min, while KrSUN-24H corresponded to 4.1 ± 0.9 mL/min, mean KrsCr-IDI to 9.1 ± 4.0 mL/min, and KrsCr 24H to 8.9 ± 4.2 mL/min, with a high regression between IDI and 24-h clearances (for IDI had R2 = 0.9149 and for 24H had R2 = 0.9595). A good correlation was also observed between KrSUN-24H and (KrSUN + KrsCR/2) (R2 = 0.7466, p < 0.01. DISCUSSION: Urine collection over a 24-h predialysis period yielded similar results for both KrSUN and KrsCr compared to collection over a longer interdialytic interval (KrSUN + KrsCr)/2 could be applied to reliably assess RKF in patients on 1WHD. CONCLUSION: The parameters evaluated are suitable for use as a routine daily method indicating the commencement and continued use of the 1WHD Incremental Program.

Urinary Liver-Type Fatty Acid-Binding Protein Predicts Residual Renal Function Decline in Patients on Peritoneal Dialysis

BACKGROUND Liver-type fatty acid-binding protein (L-FABP) is a predictive marker for the early detection of acute kidney injury; however, less is known about how useful it is for predicting residual renal function (RRF) decline in patients on peritoneal dialysis (PD). MATERIAL AND METHODS The study subjects were 35 patients on PD who underwent multiple peritoneal equilibration tests (PETs) between October 2011 and October 2019. Urinary L-FABP levels were analyzed with enzyme-linked immunosorbent assay. The relationship between baseline clinical data, including urinary L-FABP levels and the subsequent annual rate of renal Kt/V decline, was investigated. RESULTS The median follow-up duration was 11 months and the rate of renal Kt/V decline was 0.29/y. Compared with outcomes in the group with renal Kt/V preservation, renal Kt/V decline was associated with both high daily levels of urinary protein excretion (0.60 g/d [range, 0.50-0.87] vs. 0.36 g/d [range, 0.19-0.48]; P=0.01) and high daily levels of urinary L-FABP excretion (111.2 mg/d [range, 76.1-188.6] vs. 61.5 mg/d [range, 35.7-96.0]; P=0.002). Multiple logistic regression analysis showed that only high daily levels of urinary L-FABP excretion were independently associated with renal Kt/V decline (odds ratio 1.03, 95% confidence interval 1.00-1.05; P=0.001). Furthermore, higher daily levels of urinary L-FABP excretion were significantly correlated with the higher annual rate of renal Kt/V decline (r=0.71, P<0.001). CONCLUSIONS We demonstrated that daily levels of urinary L-FABP are associated with RRF decline in patients on PD. The results of the present study indicate that assessment of urinary L-FABP levels may help predict RRF decline in patients on PD.

NAT8 Variants, N-Acetylated Amino Acids, and Progression of CKD.

BACKGROUND AND OBJECTIVES: Genetic variants in NAT8, a liver- and kidney-specific acetyltransferase encoding gene, have been associated with eGFR and CKD in European populations. Higher circulating levels of two NAT8-associated metabolites, N-δ-acetylornithine and N-acetyl-1-methylhistidine, have been linked to lower eGFR and higher risk of incident CKD in the Black population. We aimed to expand upon prior studies to investigate associations between rs13538, a missense variant in NAT8, N-acetylated amino acids, and kidney failure in multiple, well-characterized cohorts. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted analyses among participants with genetic and/or serum metabolomic data in the African American Study of Kidney Disease and Hypertension (AASK; n=962), the Atherosclerosis Risk in Communities (ARIC) study (n=1050), and BioMe, an electronic health record-linked biorepository (n=680). Separately, we evaluated associations between rs13538, urinary N-acetylated amino acids, and kidney failure in participants in the German CKD (GCKD) study (n=1624). RESULTS: Of 31 N-acetylated amino acids evaluated, the circulating and urinary levels of 14 were associated with rs13538 (P<0.05/31). Higher circulating levels of five of these N-acetylated amino acids, namely, N-δ-acetylornithine, N-acetyl-1-methylhistidine, N-acetyl-3-methylhistidine, N-acetylhistidine, and N2,N5-diacetylornithine, were associated with kidney failure, after adjustment for confounders and combining results in meta-analysis (combined hazard ratios per two-fold higher amino acid levels: 1.48, 1.44, 1.21, 1.65, and 1.41, respectively; 95% confidence intervals: 1.21 to 1.81, 1.22 to 1.70, 1.08 to 1.37, 1.29 to 2.10, and 1.17 to 1.71, respectively; all P values <0.05/14). None of the urinary levels of these N-acetylated amino acids were associated with kidney failure in the GCKD study. CONCLUSIONS: We demonstrate significant associations between an NAT8 gene variant and 14 N-acetylated amino acids, five of which had circulation levels that were associated with kidney failure.

Efficacy of different urinary uric acid indicators in patients with chronic kidney disease.

BACKGROUND: Mounting studies have shown that hyperuricemia is related to kidney diseases through multiple ways. However, the application of urinary uric acid indicators in patients with reduced renal function is not clear. In this study, we aim to determine the effects of renal function on various indicators reflecting uric acid levels in patients with chronic kidney disease (CKD). METHODS: Anthropometric and biochemical examinations were performed in 625 patients with CKD recruited from Dept of Nephrology of Huadong hospital affiliated to Fudan University. Multiple regression analyses were used to study correlations of the estimated glomerular filtration rate (eGFR) with serum uric acid (SUA) and renal handling of uric acid. For further study, smooth curve plots and threshold effect analyses were applied to clarify associations between renal function and uric acid levels. RESULTS: The nonlinear relationships were observed between eGFR and urinary uric acid indicators. The obvious inflection points were observed in smooth curve fitting of eGFR and fractional excretion of uric acid (FEur), excretion of uric acid per volume of glomerular filtration (EurGF). In subsequent analyses where levels of eGFR< 15 mL/min/1.73m2 were dichotomized (CKD5a/CKD5b), patients in the CKD5a showed higher levels of FEur and EurGF while lower levels of urinary uric acid excretion (UUA), clearance of uric acid (Cur) and glomerular filtration load of uric acid (FLur) compared with CKD5b group (all P < 0.05). And there was no significant difference of SUA levels between two groups. On the other hand, when eGFR< 109.9 ml/min/1.73 m2 and 89.1 ml/min/1.73 m2, the resultant curves exhibited approximately linear associations of eGFR with Cur and FLur respectively. CONCLUSION: FEur and EurGF showed significantly compensatory increases with decreased renal function. And extra-renal uric acid excretion may play a compensatory role in patients with severe renal impairment to maintain SUA levels. Moreover, Cur and FLur may be more reliable indicators of classification for hyperuricemia in CKD patients.

Urine 6-Bromotryptophan: Associations with Genetic Variants and Incident End-Stage Kidney Disease.

Higher serum 6-bromotryptophan has been associated with lower risk of chronic kidney disease (CKD) progression, implicating mechanisms beyond renal clearance. We studied genetic determinants of urine 6-bromotryptophan and its association with CKD risk factors and incident end-stage kidney disease (ESKD) in 4,843 participants of the German Chronic Kidney Disease (GCKD) study. 6-bromotryptophan was measured from urine samples using mass spectrometry. Patients with higher levels of urine 6-bromotryptophan had higher baseline estimated glomerular filtration rate (eGFR, p < 0.001). A genome-wide association study of urine 6-bromotryptophan identified two significant loci possibly related to its tubular reabsorption, SLC6A19, and its production, ERO1A, which was also associated with serum 6-bromotryptophan in an independent study. The association between urine 6-bromotryptophan and time to ESKD was assessed using Cox regression. There were 216 ESKD events after four years of follow-up. Compared with patients with undetectable levels, higher 6-bromotryptophan levels were associated with lower risk of ESKD in models unadjusted and adjusted for ESKD risk factors other than eGFR (

Determining factors for hemodiafiltration to equal or exceed the performance of expanded hemodialysis.

The aim of the study was to compare expanded hemodialysis (HDx) with hemodiafiltration (HDF) at different infusion flows to identify the main determinants, namely blood flow (Qb), replacement volume, infusion flow (Qi), ultrafiltration flow (Quf ), filtration fraction (FF), and the point at which the effectiveness of HDF equals or exceeds that of HDx. We conducted a prospective, single-center study in 12 patients. Each patient underwent 12 dialysis sessions: six sessions with Qb 350 and six with Qb 400 mL/min; with each Qb, one session was with HDx and five sessions were with FX80 (one in HD, and four with Qi 50, 75, 90/100 mL/min or autosubstitution in postdilution HDF). The reduction ratios (RR) of urea, creatinine, ß2 -microglobulin, myoglobin, prolactin, α1 -microglobulin, α1 -acid glycoprotein, and albumin were compared intraindividually and the global removal score (GRS) was calculated. The mean replacement volume with Qb 350 mL/min was 13.77 ± 0.92 L with Qi 50 mL/min, 20.75 ± 1.17 L with Qi 75, 23.83 ± 1.92 L with Qi 90, and 27.51 ± 2.77 L with autosubstitution. Similar results were obtained with Qb 400 mL/min, and the results were only slightly higher with Qi 100 mL/min or in autosubstitution. The GRS was positively correlated with replacement volume with Qb 350 (R2  = 0.583) and with Qb 400 (R2  = 0.584); with Quf with Qb 350 (R2  = 0.556) and with Qb 400 (R2  = 0.604); and also with FF with Qb 350 (R2  = 0.556) and with Qb 400 mL/min (R2  = 0.603). The minimum convective volume in HDF from which it is possible to overcome the efficacy of HDx was 19.2 L with Qb 350 and 17.6 L with Qb 400 mL/min. The cut-off point of Quf at which HDF exceeded the effectiveness of HDx was 80.6 mL/min with Qb 350 and 74.1 mL/min with Qb 400 mL/min. The cut-off point at which FF in HDF exceeded the effectiveness of the HDx was 23.0% with Qb 350 and 18.6% with Qb 400 mL/min. In conclusion, this study confirms the superiority of postdilution HDF over HDx when replacement volume, convective volume, Quf , or FF exceeds certain values. Increasing the Qb in postdilution HDF manages to increase the convective dose and more easily overcome the HDx.

Spectral characteristics of urine from patients with end-stage kidney disease analyzed using Raman Chemometric Urinalysis (Rametrix).

Raman Chemometric Urinalysis (RametrixTM) was used to discern differences in Raman spectra from (i) 362 urine specimens from patients receiving peritoneal dialysis (PD) therapy for end-stage kidney disease (ESKD), (ii) 395 spent dialysate specimens from those PD therapies, and (iii) 235 urine specimens from healthy human volunteers. RametrixTM analysis includes spectral processing (e.g., truncation, baselining, and vector normalization); principal component analysis (PCA); statistical analyses (ANOVA and pairwise comparisons); discriminant analysis of principal components (DAPC); and testing DAPC models using a leave-one-out build/test validation procedure. Results showed distinct and statistically significant differences between the three types of specimens mentioned above. Further, when introducing "unknown" specimens, RametrixTM was able to identify the type of specimen (as PD patient urine or spent dialysate) with better than 98% accuracy, sensitivity, and specificity. RametrixTM was able to identify "unknown" urine specimens as from PD patients or healthy human volunteers with better than 96% accuracy (with better than 97% sensitivity and 94% specificity). This demonstrates that an entire Raman spectrum of a urine or spent dialysate specimen can be used to determine its identity or the presence of ESKD by the donor.

The impact of kidney dysfunction categorized by urinary to serum creatinine ratio on clinical outcomes in patients with heart failure.

Kidney dysfunction (KD) is closely associated with poor clinical outcome in patients with heart failure (HF). KD is classified as intrinsic and pre-renal KD. However, the impact of each KD on the clinical outcome in patients with HF has not yet been fully elucidated. We measured the urinary to serum creatinine (UC/SC) ratio, a marker for intrinsic and pre-renal KD, in 1009 consecutive patients with HF at admission. There were 314 cardio-renal events including HF and advanced end-stage renal dysfunction during the median follow-up period of 1154 days. There were 63 (6%) patients with intrinsic KD (UC/SC ratio < 20), 118 (12%) patients with intermediate KD (UC/SC ratio 20-40), 607 (60%) patients with pre-renal KD (UC/SC ratio > 40), and 221 (22%) patients with no KD. Multivariate Cox's proportional hazard regression analysis demonstrated that intrinsic and intermediate KDs were significantly associated with poor clinical outcome. The prediction model for cardio-renal events was significantly improved by the addition of UC/SC ratio to the confounding risk factors. Subgroup analysis in patients with HF with severely reduced glomerular filtration rates showed that the prevalence rates of intrinsic, intermediate, and pre-renal KDs were 23%, 30%, and 47%, respectively. The cardio-renal event rate was the highest in the intrinsic KD group compared with that in the other groups. Intrinsic KD was closely associated with extremely poor clinical outcome in patients with HF. The UC/SC ratio could provide important clinical information for the treatment and management of KD in patients with HF.

Associations of urinary epidermal growth factor and monocyte chemotactic protein-1 with kidney involvement in patients with diabetic kidney disease.

BACKGROUND: In diabetic kidney disease (DKD), it is important to find biomarkers for predicting initiation and progression of the disease. Besides glomerular damage, kidney tubular injury and inflammation are also involved in the development of DKD. The current study investigated the associations of urinary epidermal growth factor (uEGF), monocyte chemotactic protein-1 (MCP-1) and the uEGF:MCP-1 ratio with kidney involvement in patients at early and advanced stages of DKD. METHODS: The concentration of uEGF and uMCP-1 was measured in two Chinese population-based studies. The associations of uEGF, uMCP-1 and uEGF/MCP-1 with occurrence of DKD were studied in a cross-sectional study (n = 1811) of early stage DKD. Associations of baseline uEGF, uMCP-1 and uEGF/MCP-1 with kidney outcome were assessed in a longitudinal cohort (n = 208) of advanced-stage DKD. RESULTS: In both studies, positive correlations were found between uEGF/urine creatinine (Cr) and estimated glomerular filtration rate (eGFR) at sampling and between uMCP-1/Cr and urinary albumin:creatinine ratio (uACR). In the cross-sectional study, uEGF/Cr and uEGF/MCP-1 were negatively associated with the occurrence of DKD {odds ratio (OR) 0.65 [95% confidence interval (CI) 0.54-0.79], P < 0.001; 0.82 (0.71-0.94), P = 0.005, respectively}. In the longitudinal cohort, the uEGF:MCP-1 ratio correlated more closely with the percentage change of eGFR slope (r = 0.33, P < 0.001) as compared with uEGF/Cr or uMCP-1/Cr alone. The composite endpoint was defined as end-stage renal disease or 30% reduction of eGFR. These three markers were independently associated with composite endpoint after adjusting for potential confounders [hazard ratio 0.76 (0.59-1.00), P = 0.047 for uEGF/Cr; 1.18 (1.02-1.38), P = 0.028 for uMCP-1/Cr; 0.79 (0.68-0.91), P = 0.001 for uEGF/MCP-1]. CONCLUSION: In Chinese patients, urinary EGF/MCP-1 was negatively associated with the occurrence of DKD. Moreover, uEGF/MCP-1 had a better ability to predict the composite endpoint and correlated more closely with kidney function decline in advanced DKD as compared with uEGF/Cr or uMCP-1/Cr alone.

Increased urinary miR-196a level predicts the progression of renal injury in patients with diabetic nephropathy.

BACKGROUND: Recent data suggest that miR-196a is predominantly expressed in the kidney and plays an inhibitory role in the progress of renal interstitial fibrosis (IF). However, the predictive value of miR-196a in diabetic nephropathy (DN) remains unknown. We validated the role of urinary miR-196a in the progression of renal injury in a cohort of patients with type 2 diabetes mellitus. METHODS: Our study included 209 patients with biopsy-proven DN. The mean follow-up time was 54.03 ± 32.94 months. Histological lesions were assessed using the pathological classification established by the Renal Pathology Society. Percentages of IF and tubular atrophy were assessed using the Aperio ScanScope system. We measured the correlation of urinary miR-196a with clinical and pathological parameters using the Spearman's correlation test. The influence of urinary miR-196a on renal outcomes was assessed using Cox regression analysis. RESULTS: Urinary miR-196a levels correlated positively with proteinuria (ρ = 0.385, P < 0.001), duration of diabetes mellitus (ρ = 0.255, P < 0.001) and systolic blood pressure (ρ = 0.267, P < 0.001). The baseline estimated glomerular filtration rate (eGFR) and hemoglobin level showed a negative correlation with urinary miR-196a (ρ = -0.247, P < 0.001 and ρ = -0.236, P = 0.001, respectively). Pathologically, urinary miR-196a levels correlated with glomerular sclerosis and IF in patients with DN. Urinary miR-196a was significantly associated with progression to end-stage renal disease [hazard ratio (HR) 2.03, P < 0.001] and a 40% reduction of baseline eGFR (HR 1.75, P = 0.001), independent of age, gender, body mass index, mean arterial pressure and hemoglobinA1c level. However, urinary miR-196a did not improve predictive power to proteinuria and eGFR in DN patients. CONCLUSIONS: Increased urinary miR-196a was significantly associated with the progression of renal injury and might be a noninvasive prognostic marker of renal fibrosis in DN patients.

Serum uromodulin is associated with the severity of clinicopathological findings in ANCA-associated glomerulonephritis.

BACKGROUND: Uromodulin (UMOD), also known as Tamm-Horsfall protein, is a kidney-specific protein expressed by epithelial cells lining the thick ascending limb of the loop of Henle. In the current study, we aimed to clarify the clinical significance of UMOD in ANCA-associated glomerulonephritis (AAG). MATERIALS AND METHODS: Sixty-one biopsy-proven AAG patients were included in this study. UMOD was measured using ELISA. The relationships between serum UMOD (sUMOD) levels and various clinicopathological findings were evaluated. RESULTS: AAG was classified into four categories (focal, crescentic, mixed, and sclerotic). In addition, tubulointerstitial lesions were classified as mild, moderate, and severe. The levels of sUMOD and urinary UMOD (uUMOD) were correlated with each other. A negative correlation between sUMOD levels and serum Cr levels, and positive correlation between sUMOD levels and eGFR were found. Patients in the high sUMOD group were associated with low serum Cr levels, focal classification, and mild tubulointerstitial injury compared to the low sUMOD group. Comparing the characteristics among histopathological classes, patients in the focal class had the best renal function and the highest levels of uUMOD/Cr and sUMOD. The focal class had significantly better renal survival compared with the severe histopathological classes (crescentic, mixed, and sclerotic). In univariate logistic regression analyses, prognostic factors for severe histopathological classes were low uUMOD/Cr, high serum Cr, and low sUMOD. Multivariate analyses revealed that low sUMOD predicted severe histopathological classes independent of serum Cr. The mean levels of sUMOD were significantly different between the focal class and severe histopathological classes, with a sensitivity of 70.6% and specificity of 90.0% (cut-off 143 ng/ml, AUC 0.80) by ROC curves. CONCLUSION: Low sUMOD levels were associated with severe clinicopathological findings and might be considered as a risk factor for end stage renal disease in AAG.

Non-invasive urinary biomarkers of renal function in sickle cell disease: an overview.

Sickle cell disease (SCD) is a hereditary condition characterized by homozygosis of the hemoglobin S (HbS) gene. Marked morbimortality is observed due to chronic hemolysis, endothelial injury, and episodes of vaso-occlusion, which leads to multi-organ damage. Renal impairment is common and may have different presentations, such as deficiency in urinary acidification or concentration, glomerulopathies, proteinuria, and hematuria, frequently resulting in end-stage renal disease (ESRD). Novel biomarkers of renal function, such as kidney injury molecule 1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) and monocyte chemoattractant protein 1 (MCP-1) are being studied in order to enable early diagnosis of kidney damage in SCD.

Design and Baseline Characteristics of the Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease Trial.

BACKGROUND: Among diabetics, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality, and progression of their underlying disease. Finerenone is a novel, non-steroidal, selective mineralocorticoid-receptor antagonist which has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD), while revealing only a low risk of hyperkalemia. However, the effect of finerenone on renal and CV outcomes has not been investigated in long-term trials yet. METHODS: The Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease -(FIDELIO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important renal and CV outcomes in T2D patients with CKD. FIDELIO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 5.5 years. FIDELIO-DKD randomized 5,734 patients with an estimated glomerular filtration rate (eGFR) ≥25-<75 mL/min/1.73 m2 and albuminuria (urinary albumin-to-creatinine ratio ≥30-≤5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of primary outcome (overall two-sided significance level α = 0.05), the composite of time to first occurrence of kidney failure, a sustained decrease of eGFR ≥40% from baseline over at least 4 weeks, or renal death. CONCLUSION: FIDELIO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of renal and CV events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.

Association of urinary acidification function with the progression of diabetic kidney disease in patients with type 2 diabetes.

OBJECTIVE: Although diabetic kidney disease (DKD) has been considered as a glomerulocentric disease in the past few decades, growing evidence demonstrated that tubular damage was indispensable in its pathogenesis and progression. This study was designed to investigate the association of urinary acidification dysfunction with the progression of DKD in type 2 diabetic patients. METHODS: Here the urinary acidification functions were measured from 80 participants with renal biopsy-proven DKD. The different kinds of renal tubular transportation dysfunction were analyzed, including the dysfunction of bicarbonate reabsorption, titratable acid secretion, and ammonium secretion. In addition, patients were followed up for 17 (interquartile range, 11-32) months to evaluate the effect of urinary acidification dysfunction in the progression of DKD. RESULTS: The most common urinary acidification dysfunction was the disorder of ammonium secretion, accounting for 53.75%. The more proteinuria excretion and the lower glomerular filtration rate (GFR) were observed in the urinary titratable acid disorder group than the normal group, and the same results were obtained for ammonium secretion disorder. Urine titratable acid was positively correlated with eGFR whereas it was inversely correlated with proteinuria, serum creatinine, and BUN. Moreover, 24 h urine protein, serum creatinine, BUN and cystatin C increased from DKD stage II to stage IV, whereas the eGFR and urine titratable acid decreased in the same way. Furthermore, Kaplan-Meier analysis and Cox regression showed that the disorder of titratable acid was an independent risk factor for DKD progression. CONCLUSIONS: The dysfunction of urinary titratable acid is a potential biomarker for the severity of proteinuria, eGFR and glomerular lesions in patients with DKD. Moreover, the titratable acid disorder is an independent risk factor of the DKD progression.