Residual proteinuria and eGFR predict progression of renal impairment within 2 years in type 2 diabetic patients with nephropathy who are receiving optimal treatment with angiotensin receptor blockers

Extending the ambit of SGLT2 inhibitors beyond diabetes: a review of clinical and preclinical studies on non-diabetic kidney disease

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are novel antidiabetic agents with overwhelming cardiorenal protection. Recent trials focusing on the nephroprotective role of SGLT2i have underscored its success as a phenomenal agent in halting the progression of kidney disease in patients with and without Type 2 diabetes mellitus. Multitudes of pleiotropic effects on tubules have raised hopes for reasonable nephroprotection beyond the purview of the hyperglycemic milieu.

AREA COVERED

This review summarizes various animal and human data as evidence for the utility of SGLT2i in non-diabetic chronic kidney disease (CKD). Web-based medical database entries were searched. On the premise of existing evidence, we have discussed mechanisms likely contributing to nephroprotection by SGLT2i in patients with non-diabetic CKD.

EXPERT OPINION

Further elucidation of mechanisms of nephroprotection offered by SGLT2i is required to extend its use as a nephroprotective agent. The use of non-traditional markers of kidney damage in future studies would improve the evaluation of their role in attenuating CKD progression. Emerging animal data support the early use of SGLT2i in states of modest proteinuria for superior outcomes. Future long-term trials in patients should aim to address the time of intervention with SGLT2i during the natural disease course of CKD for best outcomes.

miRNA-483-5p Targets HDCA4 to Regulate Renal Tubular Damage in Diabetic Nephropathy

This study was designed to evaluate the diagnostic value of miR-483-5p in diabetic nephropathy (DN), and its effect and mechanism on apoptosis and inflammation of human proximal renal tubular cells (HK2) induced by high glucose (HG). Thirty healthy controls, 30 types 2 diabetes mellitus (T2DM) patients, and 28 DN patients were enrolled. miR-483-5p mRNA levels in serum were analyzed by RT-qPCR assays. The receiver operating characteristic curve (ROC) was used to analyze the diagnostic value of miR-483-5p in DN. HK2 cells were induced by HG to establish an in vitro study model. CCK-8 and flow cytometry was used to detect cell viability, apoptosis, and reactive oxygen species (ROS) generation. Inflammation levels were measured by ELISA. Luciferase reporter assay was used to detect target genes of miR-483-5p. miR-483-5p was decreased in DN patients. The decreased level of miR-483-5p was positively correlated with estimated glomerular filtration rate (eGFR) and negatively correlated with proteinuria. miR-483-5p can significantly distinguish DN patients from healthy controls and T2DM and has a high diagnostic value. miR-483-5p decreased in HK2 cells induced by HG, and overexpression of miR-483-5p reversed HG-induced decreased cell activity, increased apoptosis, ROS production, and inflammation. Histone deacetylase 4 (HDCA4) was markedly increased in DN patients and HG-induced HK2 cells. miR-483-5p directly targeted HDCA4, and increasing miR-483-5p inhibited HDCA4 increased in HG-induced HK2. In conclusion, the results indicate that reduction of miR-483-5p has a high diagnostic value in DN, and overexpression of miR-483-5p has a certain protective effect on HK2 cells induced by HG by targeting HDCA4.

Association of platelet-to-lymphocyte ratio with kidney clinicopathologic features and renal outcomes in patients with diabetic kidney disease

BACKGROUND

Growing evidence points to the pivotal role of inflammation in the pathogenesis of diabetic kidney disease (DKD). However, as an inflammation-based prognostic score, the significance of platelet-to-lymphocyte ratio (PLR) in biopsy-proven DKD remains uncertain. Therefore, the current study aimed to evaluate the association of PLR with the clinicopathological features and the progression of DKD.

METHODS

In total, 167 patients with biopsy-proven T2DKD were retrospectively recruited. Clinicopathological characteristics were compared according to the tertiles of baseline PLR. Pearson's or Spearman correlations were used to examine the associations between PLR and baseline characteristics. Assessment of the prospective relationship of PLR with the kidney outcomes defined as a doubling of baseline serum creatinine or onset of end stage renal disease (ESRD), were investigated by Kaplan-Meier survival analysis. Moreover, a cubic spline curve was further calculated to explore the significance of PLR in DKD prognosis. On top of that, identification of the risk factors associated with DKD progression was executed by a model of Cox proportional hazards.

RESULTS

Median follow-up period was 23.77 months, during which 92 (55.1%) patients confronted DKD progression. Pearson's correlation indicated that urinary protein increased along with PLR rising (r = 0.193, P = 0.012). Kaplan-Meier survival curves revealed a significantly increased probability of event-free survival in the lowest tertile of PLR compared to those in the highest tertile (P = 0.018). A statistical linear correlation between PLR and DKD development was demonstrated by a restricted cubic spline analysis (P for nonlinear = 0.784). In addition, the analyses of multivariate Cox regression indicated that elevated PLR had an association with a greater risk of DKD progression (HR 1.004, 95%CI [1.000-1.008], P = 0.035), which was verified to be an independent risk factor for renal outcomes.

CONCLUSIONS

Our findings demonstrated that the PLR was associated with proteinuria and prognosis in DKD patients. It was an independent risk factor for kidney progression in biopsy-proven DKD.

Mesenchymal Stem Cell Therapy for Diabetic Kidney Disease: A Review of the Studies Using Syngeneic, Autologous, Allogeneic, and Xenogeneic Cells

Diabetic kidney disease (DKD) is a microvascular complication of diabetes mellitus (DM) and comprises multifactorial pathophysiologic mechanisms. Despite current treatment, around 30-40% of individuals with type 1 and type 2 DM (DM1 and DM2) have progressive DKD, which is the most common cause of end-stage chronic kidney disease worldwide. Mesenchymal stem cell- (MSC-) based therapy has important biological and therapeutic implications for curtailing DKD progression. As a chronic disease, DM may impair MSC microenvironment, but there is compelling evidence that MSC derived from DM1 individuals maintain their cardinal properties, such as potency, secretion of trophic factors, and modulation of immune cells, so that both autologous and allogeneic MSCs are safe and effective. Conversely, MSCs derived from DM2 individuals are usually dysfunctional, exhibiting higher rates of senescence and apoptosis and a decrease in clonogenicity, proliferation, and angiogenesis potential. Therefore, more studies in humans are needed to reach a conclusion if autologous MSCs from DM2 individuals are effective for treatment of DM-related complications. Importantly, the bench to bedside pathway has been constructed in the last decade for assessing the therapeutic potential of MSCs in the DM setting. Laboratory research set the basis for establishing further translation research including preclinical development and proof of concept in model systems. Phase I clinical trials have evaluated the safety profile of MSC-based therapy in humans, and phase II clinical trials (proof of concept in trial participants) still need to answer important questions for treating DKD, yet metabolic control has already been documented. Therefore, randomized and controlled trials considering the source, optimal cell number, and route of delivery in DM patients are further required to advance MSC-based therapy. Future directions include strategies to reduce MSC heterogeneity, standardized protocols for isolation and expansion of those cells, and the development of well-designed large-scale trials to show significant efficacy during a long follow-up, mainly in individuals with DKD.

Prognostic nomogram and score to predict renal survival of patients with biopsy-proven diabetic nephropathy

AIMS

Both clinical and pathogenetic markers for accurate prediction of end-stage renal disease in diabetic nephropathy (DN) are lacking. This study aimed to establish an effective prognostic nomogram and a score for renal survival (RS) in biopsy-proven DN.

METHODS

Analyses were derived from 110 DN patients who underwent renal biopsy at China-Japan Friendship Hospital between January 2006 and May 2018 with DN as the only glomerular disease diagnosis. The prognostic ability of 34 baseline clinicopathologic parameters was evaluated using univariate and multivariate Cox regression analyses. The predictive accuracy and discriminative ability of the final model were measured using the calibration curve and concordance index (C-index). Internal validation of the model was assessed using bootstrap resampling.

RESULTS

Urinary proteinuria excretion, stages of chronic kidney disease, glomerular hyalinosis, and extracapillary hypercellularity were independent prognostic factors for RS, and all were selected into the nomogram. The calibration curve for the probability of survival showed good agreement between the prediction by nomogram and actual observation. The C-index for predicting survival was 0.79 (95% confidence interval (CI) 0.72-0.86). A high C-index value of 0.76 indicated good internal validation. The prognostic score had the potential to delineate two prognosis groups with median RS of 24 and 70 months, respectively.

CONCLUSIONS

The proposed nomogram and score provide a useful individualized risk estimate of renal prognosis in patients with DN.

Histologic predictors of renal outcome in diabetic nephropathy: Beyond renal pathology society classification

The prognostic utility of histologic features in patients with diabetic nephropathy (DN) classified according to the Renal Pathology Society (RPS) classification is controversial. Therefore, we aimed to evaluate the relationship between histologic changes and renal outcome in DN patients.We examined the renal outcome at November 30, 2017 of 74 adult patients (median age of 54.6 years, 69% male, 81% diabetes mellitus (DM) type 2, estimated GFR (eGFR) 29.6 mL/min) with biopsy proven DN between 2010 and 2015. The primary endpoint was renal replacement therapy (RRT) initiation.Half of the patients progressed to end stage renal disease (ESRD) during follow-up; they had lower eGFR, increased proteinuria, hematuria and serum cholesterol. Regarding the pathologic features, they were more frequently in class III and IV, had higher interstitial fibrosis and tubular atrophy score (IFTA), increased interstitial inflammation, more frequent arteriolar hyalinosis and higher glomerular basement membrane (GBM) thickness. The mean kidney survival time was 2.7 (95%CI 2.1, 3.3) years. In univariate time-dependent analyses, higher RPS DN class, increased IFTA, the presence of arteriolar hyalinosis and arteriosclerosis were associated with RRT initiation.In the fully adjusted model, the clinical characteristics associated with poor renal survival were longer duration of DM, lower eGFR, increased proteinuria and higher hematuria and the only pathologic lesions to remain significant were the GBM thickness and the IFTA.In conclusion, in this European cohort, the severity of glomerular lesions evaluated with the RPS DN classification had limited utility in predicting RRT initiation. However, IFTA and GBM thickness were significantly associated with renal survival.

Serum fibrinogen predicts diabetic ESRD in patients with type 2 diabetes mellitus

AIMS

Although increased serum fibrinogen level was often observed in patients with diabetic nephropathy (DN), its association with DN severity and progression remains unclear. The aim of this study was to investigate the relationship between the serum fibrinogen levels and clinicopathological features and renal prognosis in Chinese patients with type 2 diabetes mellitus (T2DM) and DN.

METHODS

A total of 174 patients with T2DM and biopsy-proven DN were enrolled. Patients were stratified by the quartiles of serum fibrinogen levels; Q1: <3.30 g/L; Q2: between 3.30 and 4.00 g/L; Q3: between 4.00 and 4.74 g/L; Q4:≥4.74 g/L. The renal outcomes were defined by reaching end stage renal disease (ESRD). The influence of serum fibrinogen levels on renal outcomes was evaluated using Cox regression analysis.

RESULTS

The factors associated with higher level of fibrinogen (Q3 and Q4) were diabetic retinopathy, low e-GFR, high proteinuria and severe glomerular and tubulointerstitial lesions. Importantly, in adjusted analysis, higher levels of fibrinogen were independently related with a greater risk of reaching ESRD with a hazard ratio (HR) of 1.64 per standard deviation (SD) of the natural log-transformed fibrinogen concentration (95%CI, 1.22-2.20; p = 0.001). In reference to the Q1, the risk of renal failure increased by quartiles of the serum fibrinogen level: the HRs were 7.12 for the Q2 (95%CI, 2.29-22.16; p = 0.001), 5.77 for Q3 (95%CI, 1.99-16.75; p = 0.001), and 8.81 for Q4 (95%CI, 2.79-27.80; p < 0.001).

CONCLUSIONS

These findings suggested that the elevated serum levels of fibrinogen were associated with diabetic ESRD in patients with T2DM.

Adjunctive therapy with statins reduces residual albuminuria/proteinuria and provides further renoprotection by downregulating the angiotensin II-AT1 pathway in hypertensive nephropathy

OBJECTIVES

Blockade of the renin-angiotensin II (Ang II) system by AT1 blockers (ARBs) and angiotensin-converting enzyme inhibitors retards the progression of chronic kidney disease (CKD) by reducing albuminuria/proteinuria. However, many patients with CKD suffer from residual albuminuria/proteinuria, which is an independent risk factor for CKD progression. The aim of the current study is to investigate the effect of pitavastatin, one of the adjunctive agents to ARBs, on the reduction of albuminuria/proteinuria and further renoprotection mediated by telmisartan in spontaneously hypertensive rats.

METHODS AND RESULTS

Forty-two-week-old spontaneously hypertensive rats were grouped randomly and received 8 weeks of treatments with vehicle, telmisartan, pitavastatin or a combination of telmisartan and pitavastatin. Both albuminuria and proteinuria were inhibited significantly in the telmisartan-treated group, but an obviously residual albuminuria was maintained. The combination treatment with telmisartan and pitavastatin displayed a more effective decrease in albuminuria and proteinuria, even to the normal level. Enhanced nephroprotection was also observed in this combination group, which was independent of the cholesterol-lowering effects. Further mechanistic studies revealed that the combination therapy greatly attenuated the expression of intrarenal Ang II and AT1, thereby decreasing the activation of TGF-β-Smad and NF-κB and inhibiting fibrosis and inflammation.

CONCLUSION

Adjunctive therapy with pitavastatin dramatically reduced residual albuminuria/proteinuria and enhanced nephroprotection, likely by downregulating the expression of intrarenal Ang II and AT1. It could be concluded that statins might be a promising adjunctive therapeutic agent to conventional ARB treatment in hypertensive renal damage.

Segmental Sclerosis and Extracapillary Hypercellularity Predict Diabetic ESRD

Pathogenetic markers of diabetic kidney disease (DKD) progression to ESRD are lacking. We characterized the prognostic value of histologic findings in DKD for time to ESRD in native kidney specimens from biopsies performed from 1995 to 2011 with diabetic glomerulosclerosis as the only glomerular disease diagnosis (n=109). Biopsy specimens were analyzed according to standard methods, including determination of diabetic nephropathy class, as defined by the Renal Pathology Society. Clinical data were extracted from electronic medical records. We used competing risk models, with death as the competing risk, to estimate subdistribution hazard ratios (HRs) for ESRD. All multivariable models included age, sex, black race, baseline eGFR, and baseline proteinuria. Pathologic characteristics achieving P<0.1 were added into successively complex models. ESRD occurred in 56% of patients, and 26% of patients died before reaching ESRD. In univariate analyses, diabetic nephropathy class was not statistically significant in predicting time to ESRD. The final multivariable model (n=106) showed a borderline association between mild mesangial expansion and decreased risk for ESRD (subdistribution HR, 0.64; 95% confidence interval, 0.40 to 1.00). Poor prognostic factors in the final model included segmental sclerosis and extracapillary hypercellularity (subdistribution HR, 2.04; 95% confidence interval, 1.36 to 3.05; and subdistribution HR, 2.21; 95% confidence interval, 1.19 to 4.11, respectively). In conclusion, we identified segmental sclerosis and extracapillary hypercellularity as novel, poor prognostic indicators of time from DKD to ESRD. Whether these indicators represent a distinct pathogenetic phenotype of DKD will require a large study with a broad spectrum of disease severity.

Prognostic value of proteinuria and glomerular filtration rate on Taiwanese patients with diabetes mellitus and advanced chronic kidney disease: a single center experience

BACKGROUND

Several risk factors were associated with poor outcomes in diabetic patients with chronic kidney disease (CKD). However, few studies addressed the prognostic implications of these factors in advanced CKD. Our study aimed to provide more evidence for risk factor stratification of diabetic patients with advanced CKD.

METHOD

A total of 447 diabetic patients with advanced CKD, age of 18-80, who visited the nephrology out-patient clinic were enrolled. All patients were in stage 3B-5 CKD. The primary outcomes included long-term renal replacement therapy and mortality. The occurrence of cardiovascular events was also analyzed as secondary outcome. Multivariate Cox regression models were used to address each risk factor in this cohort. We also used this cohort to evaluate the validity of the modified diabetic nephropathy score.

RESULTS

Patients with lower estimated glomerular filtration rate (eGFR) were associated with higher degree of proteinuria. In the multivariate Cox regression model, eGFR and the degree of proteinuria were both strong outcome predictors. The effects of glycosylated hemoglobin and blood pressure in this advanced CKD cohort were minimal. Elder patients with advanced CKD had a higher mortality rate, but commenced less renal replacement therapy. Applying these indicator analyses, we proposed a modified diabetic nephropathy score for outcome prediction.

CONCLUSIONS

Our analysis demonstrated the impact of eGFR and proteinuria in the advanced CKD group. Indicators in early CKD possessed a different prognostic profile in this advanced CKD cohort, therefore, necessitating a modified scoring system.

Glomerular diseases outcome at one year in a tertiary care centre

Objectives:

To determine outcome in primary and secondary glomerular diseases at one year follow up.

Methods:

Study design is observational cohort, done in out-patient department, Dow Iinternational Medical College, DUHS. All information gathered on a proforma. All patients with dipstick positive proteinuria and clinical glomerular disease were included in study. Patients with no proteinuria were excluded so were patients with stage 5 CKD. Patients were followed for proteinuria and renal insufficiency at completion of one year follow up. Statistical analysis was done on SPSS version 16.

Result:

Total number of patients who completed one year follow up was 173. Mean age of patients was 51.67+ 10.16 (range 15 to 75 years). Ninety two (53.2%), were males and 81(46.8%) were females, ratio being 1.1: 1.0. Mean weight of our patients was 67.43+ 14.13 Kg, (35 to 107 kg). Commonest cause of glomerular disease in our patient was diabetic nephropathy which was seen in 94.2% patients. Commonest associated problem with glomerular disease was hypertension seen in 66.5% of patients. Four out of 173 patients had stage 5 CKD at end of follow up at one year while quantitativ proteinuria remained same at one year follow up.

Conclusion:

One year follow up is critical for patients with glomerular disease associated with stage 4 CKD as progression to end stage renal failure may be seen within one year in these patients.

Effect of pentoxifylline on renal function and urinary albumin excretion in patients with diabetic kidney disease: the PREDIAN trial

Diabetic kidney disease (DKD) is the leading cause of ESRD. We conducted an open-label, prospective, randomized trial to determine whether pentoxifylline (PTF), which reduces albuminuria, in addition to renin-angiotensin system (RAS) blockade, can slow progression of renal disease in patients with type 2 diabetes and stages 3-4 CKD. Participants were assigned to receive PTF (1200 mg/d) (n=82) or to a control group (n=87) for 2 years. All patients received similar doses of RAS inhibitors. At study end, eGFR had decreased by a mean±SEM of 2.1±0.4 ml/min per 1.73 m(2) in the PTF group compared with 6.5±0.4 ml/min per 1.73 m(2) in the control group, with a between-group difference of 4.3 ml/min per 1.73 m(2) (95% confidence interval [95% CI], 3.1 to 5.5 ml/min per 1.73 m(2); P<0.001) in favor of PTF. The proportion of patients with a rate of eGFR decline greater than the median rate of decline (0.16 ml/min per 1.73 m(2) per month) was lower in the PTF group than in the control group (33.3% versus 68.2%; P<0.001). Percentage change in urinary albumin excretion was 5.7% (95% CI, -0.3% to 11.1%) in the control group and -14.9% (95% CI, -20.4% to -9.4%) in the PTF group (P=0.001). Urine TNF-α decreased from a median 16 ng/g (interquartile range, 11-20.1 ng/g) to 14.3 ng/g (interquartile range, 9.2-18.4 ng/g) in the PTF group (P<0.01), with no changes in the control group. In this population, addition of PTF to RAS inhibitors resulted in a smaller decrease in eGFR and a greater reduction of residual albuminuria.