Microscopic Haematuria and Clinical Outcomes in Patients With Stage 3-5 Nondiabetic Chronic Kidney Disease

Development and validation of a predictive model for end-stage renal disease in systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) affects many populations. This study aims to develop a predictive model and create a nomogram for assessing the risk of end-stage renal disease (ESRD) in patients diagnosed with SLE. Data from electronic health records of SLE patients treated at the Affiliated Hospital of North Sichuan Medical College between 2013 and 2023 were collected. The dataset underwent thorough cleaning and variable assignment procedures. Subsequently, variables were selected using one-way logistic regression and lasso logistic regression methods, followed by multifactorial logistic regression to construct nomograms. The model's performance was assessed using calibration, receiver operating characteristic (ROC), and decision curve analysis (DCA) curves. Statistical significance was set at P < 0.05. The predictive variables for ESRD development in SLE patients included anti-GP210 antibody presence, urinary occult blood, proteinuria, white blood cell count, complement 4 levels, uric acid, creatinine, total protein, globulin, glomerular filtration rate, pH, specific gravity, very low-density lipoprotein, homocysteine, apolipoprotein B, and absolute counts of cytotoxic T cells. The nomogram exhibited a broad predictive range. The ROC area under the curve (AUC) was 0.886 (0.858-0.913) for the training set and 0.840 (0.783-0.897) for the testing set, indicating good model performance. The model demonstrated both applicability and significant clinical benefits. The developed model presents strong predictive capabilities and considerable clinical utility in estimating the risk of ESRD in patients with SLE.

Asymptomatic hematuria in children: Korean Society of Pediatric Nephrology recommendations for diagnosis and management

Hematuria is a relatively common condition among school-aged children. Because international guidelines for asymptomatic hematuria in children are unavailable, developing practical guidelines for the diagnosis and management of asymptomatic hematuria based on scientific evidence while considering real-world practice settings, values, and patient and physician preferences is essential. The Korean Society of Pediatric Nephrology developed clinical guidelines to address key questions regarding the diagnosis and management of asymptomatic hematuria in children.

The Significance of Hematuria in Podocytopathies

BACKGROUND

Hematuria is frequently present in podocytopathies, but its significance and prognostic value is not well described in these proteinuric kidney diseases. This study describes the prevalence and association between hematuria and kidney-related outcomes in these disorders.

METHODS

Hematuria was assessed at the initial urinalysis in participants with the following podocytopathies-membranous nephropathy, minimal change disease, and FSGS-in the Nephrotic Syndrome Study Network and Cure Glomerulonephropathy cohorts with >24 months of follow-up. Multivariable Cox proportional hazards models were fit for time to composite outcome (kidney failure or 40% decline in eGFR and eGFR <60 ml/min per 1.73 m 2 ) and proteinuria remission (urine protein-to-creatinine ratio [UPCR] <0.3 mg/mg).

RESULTS

Among the 1516 adults and children in the study, 528 participants (35%) had FSGS, 499 (33%) had minimal change disease, and 489 (32%) had membranous nephropathy. Median (interquartile range) time from biopsy until the initial study urinalysis was 260 (49-750) days, and 498 participants (33%) were positive for hematuria. Participants with hematuria compared with those without were older (37 [16-55] versus 33 [12-55] years), more likely to have an underlying diagnosis of membranous nephropathy (44% versus 27%), had shorter time since biopsy (139 [27-477] versus 325 [89-878] days), and had higher UPCR (3.8 [1.4-8.0] versus 0.9 [0.1-3.1] g/g). After adjusting for diagnosis, age, sex, UPCR, eGFR, time since biopsy, and study cohort, hematuria was associated with a higher risk of reaching the composite outcome (hazard ratio, 1.31; 95% confidence interval, 1.04 to 1.65; P value, 0.02) and lower rate of reaching proteinuria remission (hazard ratio, 0.80; 95% confidence interval, 0.65 to 0.98; P value, 0.03).

CONCLUSIONS

Hematuria is prevalent among participants with the three podocytopathies and is significantly and independently associated with worse kidney-related outcomes, including both progressive loss of kidney function and remission of proteinuria.

Practice facilitation for scale up of clinical decision support for hypertension management: study protocol for a cluster randomized control trial

BACKGROUND

Only half of patients with hypertension have adequately controlled blood pressure. Clinical decision support (CDS) has the potential to overcome barriers to delivering guideline-recommended care and improve hypertension management. However, optimal strategies for scaling CDS have not been well established, particularly in small, independent primary care practices which often lack the resources to effectively change practice routines. Practice facilitation is an implementation strategy that has been shown to support process changes. Our objective is to evaluate whether practice facilitation provided with hypertension-focused CDS can lead to improvements in blood pressure control for patients seen in small primary care practices.

METHODS/DESIGN

We will conduct a cluster randomized control trial to compare the effect of hypertension-focused CDS plus practice facilitation on BP control, as compared to CDS alone. The practice facilitation intervention will include an initial training in the CDS and a review of current guidelines along with follow-up for coaching and integration support. We will randomize 46 small primary care practices in New York City who use the same electronic health record vendor to intervention or control. All patients with hypertension seen at these practices will be included in the evaluation. We will also assess implementation of CDS in all practices and practice facilitation in the intervention group.

DISCUSSION

The results of this study will inform optimal implementation of CDS into small primary care practices, where much of care delivery occurs in the U.S. Additionally, our assessment of barriers and facilitators to implementation will support future scaling of the intervention.

CLINICALTRIALS

gov Identifier: NCT05588466.

Machine-learning enhancement of urine dipstick tests for chronic kidney disease detection

OBJECTIVE

Screening for chronic kidney disease (CKD) requires an estimated glomerular filtration rate (eGFR, mL/min/1.73 m2) from a blood sample and a proteinuria level from a urinalysis. We developed machine-learning models to detect CKD without blood collection, predicting an eGFR less than 60 (eGFR60 model) or 45 (eGFR45 model) using a urine dipstick test.

MATERIALS AND METHODS

The electronic health record data (n = 220 018) obtained from university hospitals were used for XGBoost-derived model construction. The model variables were age, sex, and 10 measurements from the urine dipstick test. The models were validated using health checkup center data (n = 74 380) and nationwide public data (KNHANES data, n = 62 945) for the general population in Korea.

RESULTS

The models comprised 7 features, including age, sex, and 5 urine dipstick measurements (protein, blood, glucose, pH, and specific gravity). The internal and external areas under the curve (AUCs) of the eGFR60 model were 0.90 or higher, and a higher AUC for the eGFR45 model was obtained. For the eGFR60 model on KNHANES data, the sensitivity was 0.93 or 0.80, and the specificity was 0.86 or 0.85 in ages less than 65 with proteinuria (nondiabetes or diabetes, respectively). Nonproteinuric CKD could be detected in nondiabetic patients under the age of 65 with a sensitivity of 0.88 and specificity of 0.71.

DISCUSSION AND CONCLUSIONS

The model performance differed across subgroups by age, proteinuria, and diabetes. The CKD progression risk can be assessed with the eGFR models using the levels of eGFR decrease and proteinuria. The machine-learning-enhanced urine-dipstick test can become a point-of-care test to promote public health by screening CKD and ranking its risk of progression.

Association between microscopic hematuria and albuminuria in patients with chronic kidney disease caused by diabetes and hypertension: the Fukuoka Kidney disease Registry Study

BACKGROUND

The association between microscopic hematuria (MH) and albuminuria in patients with chronic kidney disease (CKD) caused by diabetes and hypertension remains unclear.

METHODS

The Fukuoka Kidney disease Registry Study is a Japanese multicenter prospective cohort study of 4476 patients with non-dialysis-dependent CKD. In this cohort, we conducted a cross-sectional study in 994 patients with diabetic nephropathy and hypertensive nephrosclerosis. Patients were divided into three groups according to erythrocyte count in urine sediment [T1: < 5/high power field (HPF); T2: 5-9/HPF; T3: ≥ 10/HPF]. Macroalbuminuria was defined as urinary albumin-creatinine ratio > 300 mg/g. Associations between the degree of MH (T1-T3) and the prevalence of macroalbuminuria were analyzed using logistic regression.

RESULTS

The prevalence of macroalbuminuria was 50.8%, 50.4%, and 67.4% in T1 (n = 725), T2 (n = 226), and T3 (n = 43), respectively. The multivariable-adjusted odds ratios for the presence of macroalbuminuria were 0.95 [95% confidence interval (CI) 0.65-1.39; P = 0.86] and 2.50 (95% CI 1.15-5.47; P = 0.022) for patients in T2 and T3, respectively, compared with patients in T1.

CONCLUSIONS

MH with erythrocytes ≥ 10/HPF was significantly associated with increased prevalence of macroalbuminuria in patients with non-dialysis-dependent CKD caused by diabetes and hypertension.

The application of new complex indicators in the detection of urine

BACKGROUND

Accurate diagnosis and assessment of hematuria is crucial for the early detection of chronic kidney disease(CKD). As instability of urinary RBC count (URBC) often results with clinical uncertainty, therefore new urinary indexes are demanded to improve the accuracy of diagnosis of hematuria. In this study, we aimed to investigate the benefit of applying new complex indicators based on random urine red blood cell counts confirmed in hematuric kidney diseases.

METHODS

All patients enrolled underwent renal biopsy, and their clinical information was collected. Urinary and blood biomedical indexes were implemented with red blood cell counts to derive complex indicators. Patients were divided into two groups (hematuria-dominant renal histologic lesions and non-hematuria-dominant renal histologic lesions) based on their renal pathological manifestations. The target index was determined by comparing the predictive capabilities of the candidate parameters for hematuric kidney diseases. Hematuria stratification was divided into four categories based on the scale of complex indicators and distributional features. The practicality of the new complex indicators was demonstrated by fitting candidate parameters to models comprising demographic information.

RESULTS

A total of 1,066 cases (678 hematuria-dominant renal histologic lesions) were included in this study, with a mean age of 44.9 ± 15 years. In differentiating hematuria-dominant renal histologic lesion from the non-hematuria-dominant renal histologic lesion, the AUC value of "The ratio of the random URBC to 24-h albumin excretion" was 0.76, higher than the standard approach of Lg (URBC) [AUC = 0.744] (95% Confidence interval (CI) 0.712 ~ 0.776). The odds ratio of hematuria-dominant renal histologic lesion (Type I) increased from Q2 (3.81, 95% CI 2.66 ~ 5.50) to Q4 (14.17, 95% CI 9.09 ~ 22.72). The predictive model, composed of stratification of new composite indexes, basic demographic characteristics, and biochemical parameters, performed best with AUC value of 0.869 (95% CI 0.856-0.905).

CONCLUSION

The new urinary complex indicators improved the diagnostic accuracy of hematuria and may serve as a useful parameter for screening hematuric kidney diseases.

Association of microscopic hematuria with long-term mortality in patients with hypertensive crisis

BACKGROUND

Microscopic hematuria is associated with increased risk of developing chronic kidney function impairment and even death. However, data on the long-term mortality risk associated with microscopic hematuria among patients with hypertensive crisis are scarce. We hypothesized that microscopic hematuria at initial presentation in patients with hypertensive crisis would be associated with increased long-term mortality.

METHODS

This retrospective study included patients admitted to the emergency department between 2016 and 2019 for hypertensive crisis (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg). Microscopic hematuria was defined as ≥ 3 red blood cells per high-power field on microscopic evaluation of urine.

RESULTS

Among 3595 patients, 1359 (37.8%) had microscopic hematuria. The 3-year all-cause mortality in patients with and without microscopic hematuria was 25.5% and 16.3%, respectively. After adjusting for confounding variables, patients with microscopic hematuria (adjusted HR, 1.30; 95% CI 1.10-1.54) showed a significantly higher risk of 3-year all-cause mortality than patients without microscopic hematuria. In a subgroup analysis based on the presence of proteinuria, microscopic hematuria was a significant predictor of all-cause mortality in patients without proteinuria (adjusted HR, 1.61; 95% CI 1.28-2.03) but not in patients with proteinuria.

CONCLUSION

Microscopic hematuria was a significant predictor of all-cause mortality in patients with hypertensive crisis. Our study suggests that microscopic hematuria can be a useful prognostic marker and may permit early detection of patients with an increased risk of death. Clinicians in the emergency department should consider screening for kidney function using urine analysis during the initial assessment of patients with hypertensive crisis.

Hematuria and subsequent long-term risk of end-stage kidney disease: A Danish population-based cohort study

BACKGROUND

Hematuria is a frequent incidental clinical finding and may be a symptom of pre-existing underlying benign or malignant urinary tract or kidney disease. However, in patients with no apparent underlying cause of hematuria, long-term prognosis of hematuria remains unknown.

OBJECTIVES

To assess the long-term risk of end-stage-kidney disease (ESKD) in patients with a hospital-based hematuria diagnosis and no apparent underlying cause.

METHODS

Patients with a hospital diagnosis of hematuria were included and matched in a 1:5 ratio with comparison persons from the background population by age, sex and residency. We calculated the cumulative risk of ESKD considering death as a competing risk. Furthermore, we computed unadjusted and adjusted hazard ratios with 95% confidence intervals using Cox hazard regression with adjustment for age, sex, and comorbidities.

RESULTS

We included 170,189 hematuria-diagnosed patients. The absolute 10-year risk of ESKD was 0.7% (95%CI: 0.7-0.8) in patients with hematuria and 0.4% (95%CI: 0.3-0.4) in comparison persons, hence yielding an overall adjusted hazard ratio of 1.6 (95%CI: 1.4-1.7). Hematuria also increased the risk of EKSD in patients with pre-existing comorbidities like diabetes (adjusted HR: 1.3 [95%CI: 1.1-1.5]) and urogenital cancer (adjusted HR: 1.4 ([95%CI: 1.1-1.9]), whereas no association was observed in patients with previous kidney disease (adjusted HR: 0.9 (95%CI: 0.8-1.0).

CONCLUSION

A hospital-based hematuria diagnosis in patients with no apparent underlying cause of hematuria is a marker of an increased risk of future ESKD.

Automated urine sediment analyzers underestimate the severity of hematuria in glomerular diseases

Hematuria, either glomerular or extraglomerular, is defined as 3 or more red blood cells (RBCs)/high power field. Currently, urinalyses are commonly performed using automated urine sediment analyzers. To assess whether RBC counting by automated urine sediment analyzers is reliable for defining hematuria in glomerular disease, random specimen urinalyses of men with nephritic glomerular disease (7674 urinalyses) and bladder cancer (12,510 urinalyses) were retrospectively reviewed. Urine RBCs were counted by an automated urine sediment analyzer based on flow cytometry (UF-1000i, Sysmex Corporation) or digital image analysis (Cobas 6500, Roche Diagnostics GmbH). In about 20% of urine specimens, the specific gravity was less than 1.010, making the RBC counts unreliable. In the urine specimens with specific gravity ≥ 1.010, RBC counts measured using either UF-1000i or Cobas 6500 were well correlated with the positive grades in the dipstick blood test. However, at a trace, 1+, or higher positive dipstick tests for blood, RBC counts were graded significantly lower in glomerular disease than in bladder cancer. The findings suggest that RBC counting by UF-1000i or Cobas 6500 underestimates the severity of hematuria in glomerular disease, possibly because dysmorphic RBCs in glomerular disease are susceptible to hemolysis and/or fail to be properly recognized.

Cross-sectional and longitudinal associations between dipstick hematuria and chronic kidney disease in patients with type 2 diabetes

AIMS

To examine the association of dipstick hematuria with kidney function and albuminuria in patients with type 2 diabetes (T2D).

METHODS

A total of 7,945 patients with T2D were studied. In the cross-sectional study, patients were classified into 6 groups based on the stage of albuminuria and estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73 m² at baseline. In the longitudinal study where patients were classified by the presence of hematuria, the primary composite endpoint was a 30% decrease in eGFR from baseline or the initiation of kidney replacement therapy. Other outcomes included eGFR slope and stage progression of albuminuria.

RESULTS

Cross-sectionally, hematuria was more prevalent in patients with more advanced stages of albuminuria and with lower eGFR, independently of each other. In the longitudinal study, patients with hematuria experienced 50% increased incidence of the primary endpoint (p < 0.001). The eGFR slope was steeper in patients with hematuria than in those without hematuria (p < 0.001). On the other hand, hematuria was unlikely to be associated with the progression of albuminuria.

CONCLUSIONS

In patients with T2D, dipstick hematuria was associated with prevalent albuminuria and reduced eGFR, as well as faster decline in kidney function but not higher risk of development or progression of albuminuria.

Higher cardiovascular mortality in men with persistent dipstick hematuria

BACKGROUND

We previously reported that dipstick hematuria (UH) was associated with higher all-cause mortality in men, but not in women. We extended the observation and examined the causes of death using repeated urinalysis in men.

METHODS

Subjects were those who participated the Tokutei-Kenshin between 2008 to 2015 in seven districts. Using National database of death certificate, we identified those who might have died and confirmed further with the collaborations of the regional National Health Insurance agency and public health nurses. Dipstick results of 1 + and higher were defined as hematuria. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using the Cox proportional hazard analysis. We adjusted for age, body mass index, eGFR, proteinuria, comorbid condition (diabetes mellitus, hypertension, and dyslipidemia), past history (stroke, heart disease, and kidney disease), and lifestyle (smoking, drinking, walking, and exercise).

RESULTS

A total of 170,119 men were studied and 70,350 (41.4% of the total) were re-examined next year. The prevalence of UH (-/-), UH (-/+), UH (±), and UH (+ /+) was 77.2% (N = 54,298), 14.0% (N = 9,838), 1.4% (N = 1014) and 7.4% (N = 5,200), respectively. We identified 1,162 deaths (1.7% of the total of the re-examined). The adjusted HR (95% CI) was 1.49 (1.22-1.81) for all-cause mortality and 1.83 (1.23-2.71) for cardiovascular death compared to those with UH (-/-), respectively. However, that for cancer mortality risk was not significant: 1.23 (0.92-1.64).

CONCLUSIONS

In men, persistent dipstick hematuria is a significantly risk factor of all-cause mortality, in particular cardiovascular death among general screening participants.

Association of dipstick hematuria with all-cause mortality in the general population: results from the specific health check and guidance program in Japan

Background

Dipstick urine tests are used for general health screening in Japan. The effects of this screening on mortality have not been examined, especially with regard to hematuria.

Methods

Subjects were those who participated in the 2008 Tokutei-Kenshin (nationwide specific health check and guidance program) in six districts in Japan. Using the national database of death certificates from 2008 to 2012, we identified subjects who might have died. We verified the candidates in collaboration with the regional National Health Insurance agency and public health nurses. Data were released to the research team supported by the Ministry of Health, Labor, and Welfare of Japan. Dipstick results of 1+ and higher were defined as hematuria (+). Hazard ratio (HR) [95% confidence interval (CI)] was calculated using the Cox proportional hazard analysis.

Results

Among 112 115 subjects, we identified that 1290 had died by the end of 2012. In hematuria (-) subjects, the crude mortality rates were 1.2% (1.8% in men, 0.7% in women), whereas in hematuria (+) subjects, they were 1.1% (2.9% in men, 0.7% in women). After adjusting for age, body mass index, estimated glomerular filtration rate, proteinuria, comorbid condition (diabetes mellitus, hypertension and dyslipidemia), past history (stroke, heart disease and kidney disease) and lifestyle (smoking, drinking, walking and exercise), the HR (95% CI) for dipstick hematuria (+) in men was 1.464 (1.147-1.846; P = 0.003), whereas that for hematuria (-) was 0.820 (0.617-1.073; P = 0.151).

Conclusions

Dipstick hematuria is significantly associated with mortality in men among Japanese community-based screening participants.

Hematuria as a risk factor for progression of chronic kidney disease and death: findings from the Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

Hematuria is associated with chronic kidney disease (CKD), but has rarely been examined as a risk factor for CKD progression. We explored whether individuals with hematuria had worse outcomes compared to those without hematuria in the CRIC Study.

METHODS

Participants were a racially and ethnically diverse group of adults (21 to 74 years), with moderate CKD. Presence of hematuria (positive dipstick) from a single urine sample was the primary predictor. Outcomes included a 50% or greater reduction in eGFR from baseline, ESRD, and death, over a median follow-up of 7.3 years, analyzed using Cox Proportional Hazards models. Net reclassification indices (NRI) and C statistics were calculated to evaluate their predictive performance.

RESULTS

Hematuria was observed in 1145 (29%) of a total of 3272 participants at baseline. Individuals with hematuria were more likely to be Hispanic (22% vs. 9.5%, respectively), have diabetes (56% vs. 48%), lower mean eGFR (40.2 vs. 45.3 ml/min/1.73 m2), and higher levels of urinary albumin > 1.0 g/day (36% vs. 10%). In multivariable-adjusted analysis, individuals with hematuria had a greater risk for all outcomes during the first 2 years of follow-up: Halving of eGFR or ESRD (HR Year 1: 1.68, Year 2: 1.36), ESRD (Year 1: 1.71, Year 2: 1.39) and death (Year 1:1.92, Year 2: 1.77), and these associations were attenuated, thereafter. Based on NRIs and C-statistics, no clear improvement in the ability to improve prediction of study outcomes was observed when hematuria was included in multivariable models.

CONCLUSION

In a large adult cohort with CKD, hematuria was associated with a significantly higher risk of CKD progression and death in the first 2 years of follow-up but did not improve risk prediction.

Hematuria and Renal Outcomes in Patients With Diabetic Chronic KidneyDisease

BACKGROUND

Hematuria may indicate nondiabetic renal disease in diabetic chronic kidney disease (CKD). However, some studies have reported that hematuria is noted in diabetic nephropathy and is associated with albuminuria. Hematuria is a risk factor for end-stage renal disease in glomerulonephritis, but its prognostic value in diabetic CKD is unknown. We investigated the factors associated with hematuria and the prognostic value of hematuria in patients with diabetic CKD.

MATERIAL AND METHODS

We included 1958 patients with type 2 diabetes and CKD stages 1-5, and 111 patients underwent renal biopsy. Patients in the biopsied cohort were younger and had more severe proteinuria, compared with those in the total cohort; hematuria was associated with nondiabetic renal disease.

RESULTS

In the total cohort, hematuria was observed in 15.0% of the patients and was associated with young age, a lower estimated glomerular filtration rate, proteinuria, high blood pressure and short diabetes duration. Hematuria was significantly associated with an increased risk (hazard ratio 1.39, 95% CI: 1.10-1.76, P < 0.001) of end-stage renal disease, particularly in patients with CKD stages 1-3 or a urine protein-to-creatinine ratio of <1,500mg/g (P for interaction < 0.05). The odds ratio of hematuria for rapid renal progression was 1.81 (95% CI: 1.29-2.53, P < 0.001).

CONCLUSIONS

Hematuria is associated with nondiabetic renal disease in biopsied patients with diabetic CKD and is associated with an increased risk of end-stage renal disease in patients with early diabetic CKD.

Risk factors for progression of chronic kidney disease in the EPPIC trials and the effect of AST-120

Background

Two randomized, double-blind, placebo-controlled trials (EPPIC-1 and EPPIC-2) investigated the efficacy and safety of AST-120, an oral spherical carbon adsorbent, in adults with chronic kidney disease (CKD). While the benefit of adding AST-120 to standard therapy was not supported by these trials, we performed a post hoc analysis to focus on CKD progression and to determine the risk factors for the primary endpoint in the EPPIC trial population.

Methods

In the EPPIC trials, patients were randomly assigned 1:1 to treatment with AST-120 or placebo. The primary endpoint was a composite of dialysis initiation, kidney transplantation, or doubling of serum creatinine. The EPPIC trial pooled population was evaluated with the same statistical methods used for analysis of the primary and secondary efficacy endpoints. The trials were registered on ClinicalTrials.gov (NCT00500682 [EPPIC-1] and NCT00501046 [EPPIC-2]).

Results

An analysis of the placebo population suggested baseline urinary protein to urinary creatinine ratio (UP/UCr) ≥1.0 and hematuria were independent risk factors for event occurrence and eGFR lowering. Analysis of the high risk patients revealed a difference in the primary endpoint occurrence between treatment groups, if angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers were administered (hazard ratio 0.74, 95% confidence interval 0.56–0.96). Also, the eGFR changes from baseline in the AST-120 group were smaller than that in the placebo group (P = 0.035).

Conclusions

CKD progression may have an association with baseline UP/UCr and hematuria. Treatment with AST-120 may delay the time to the primary endpoint in patients with progressive CKD receiving standard therapy, thus warranting further investigation.

Electronic supplementary material

The online version of this article (doi:10.1007/s10157-017-1447-0) contains supplementary material, which is available to authorized users.

Diabetic Retinopathy and Clinical Parameters Favoring the Presence of Diabetic Nephropathy could Predict Renal Outcome in Patients with Diabetic Kidney Disease

Diabetes duration, diabetic retinopathy (DR), and a diagnostic model have been proposed as clinical parameters favoring the presence of diabetic nephropathy (DN) in biopsied patients with diabetic kidney disease. DN, compared with non-diabetic renal disease, had poorer renal outcomes. We tested whether these clinical parameters favoring DN are associated with poorer renal outcomes in non-biopsied patients. In this study, 1330 patients with type 2 diabetes and chronic kidney disease stages 1-4 were included and divided according to diabetes mellitus (DM) duration >8 years, DR, or a diagnostic model for DN. These clinical parameters favoring DN were found in 62-77% of patients and associated with higher levels of proteinuria. In a Cox survival analysis, DR and the diagnostic model favoring DN were associated with an increased risk for end-stage renal disease with adjusted hazard ratios of 1.69 (95% CI: 1.16-2.45, P = 0.006) and 1.66 (95% CI: 1.05-2.61, P = 0.029), respectively. DR was associated with an increased risk for rapid renal disease progression. DM >8 years was not associated with renal outcome. Propensity score-matched analyses also showed similar results. In conclusion, DR and the diagnostic model favoring DN were associated with poorer renal outcomes.

Sublytic C5b-9 Induces Glomerular Mesangial Cell Apoptosis through the Cascade Pathway of MEKK2-p38 MAPK-IRF-1-TRADD-Caspase 8 in Rat Thy-1 Nephritis

The apoptosis of glomerular mesangial cells (GMCs) in the early phase of rat Thy-1 nephritis (Thy-1N), a model of human mesangioproliferative glomerulonephritis (MsPGN), is primarily triggered by sublytic C5b-9. However, the mechanism of GMC apoptosis induced by sublytic C5b-9 remains unclear. In this study, we demonstrate that expressions of TNFR1-associated death domain-containing protein (TRADD) and IFN regulatory factor-1 (IRF-1) were simultaneously upregulated in the renal tissue of Thy-1N rats (in vivo) and in GMCs under sublytic C5b-9 stimulation (in vitro). In vitro, TRADD was confirmed to be a downstream gene of IRF-1, because IRF-1 could bind to TRADD gene promoter to promote its transcription, leading to caspase 8 activation and GMC apoptosis. Increased phosphorylation of p38 MAPK was verified to contribute to IRF-1 and TRADD production and caspase 8 activation, as well as to GMC apoptosis induced by sublytic C5b-9. Furthermore, phosphorylation of MEK kinase 2 (MEKK2) mediated p38 MAPK activation. More importantly, three sites (Ser^153/164/239) of MEKK2 phosphorylation were identified and demonstrated to be necessary for p38 MAPK activation. In addition, silencing of renal MEKK2, IRF-1, and TRADD genes or inhibition of p38 MAPK activation in vivo had obvious inhibitory effects on GMC apoptosis, secondary proliferation, and urinary protein secretion in rats with Thy-1N. Collectively, these findings indicate that the cascade axis of MEKK2-p38 MAPK-IRF-1-TRADD-caspase 8 may play an important role in GMC apoptosis following exposure to sublytic C5b-9 in rat Thy-1N.