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The tubulointerstitial compartment comprises most of the kidney parenchyma. Inflammation in this compartment (tubulointerstitial nephritis—TIN) can be acute and resolves if the offending factor is withdrawn or may enter a chronic process leading to irreversible kidney damage. Etiologic factors differ, including different exposures, infections, and autoimmune and genetic tendency, and the initial damage can be acute, recurrent, or permanent, determining whether the acute inflammatory process will lead to complete healing or to a chronic course of inflammation leading to fibrosis. Clinical and laboratory findings of TIN are often nonspecific, which may lead to delayed diagnosis and a poorer clinical outcome. We provide a general review of TIN, with special mention of the molecular pathophysiological mechanisms of the associated kidney damage. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to explore the value of Doppler ultrasound imaging and shear wave elastography (SWE) in evaluating renal interstitial fibrosis/tubular atrophy (IFTA). Methods: During April 2019 and November 2023, biopsy-proven IgA nephropathy (IgAN) patients were enrolled in our study. Conventional ultrasound, Doppler ultrasound imaging and SWE measurements were performed, and related parameters were collected. According to the Oxford classification of IgAN, interstitial fibrosis/tubular atrophy (T) lesions were grouped into T0, T1 and T2 group. Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic accuracy of SWE in identifying IFTA. Results: A total of 100 IgAN patients were enrolled in the final cohort. 67 patients were in the T0 group, and 33 patients were in the T1/T2 group. The average SWE values were 42.17 ± 9.11 kPa in the T0 group and 36.83 ± 10.32 kPa in the T1/T2 group (p = 0.01). Multivariate logistic regression revealed that the SWE value and end diastolic velocity (EDV) of the interlobar artery were found to be independent risk factors for IFTA. For the diagnosis of IFTA, the area under the ROC curve (AUC) of SWE alone was 0.652, whereas the AUC of SWE in combination with the EDV was 0.807 (p = 0.008). Conclusion: The combination of Doppler ultrasound imaging and SWE measurements could improve the diagnostic performance of quantitative assessment of IFTA in IgAN patients. [ABSTRACT FROM AUTHOR]

Background: IgA nephropathy (IgAN), the most common primary glomerulonephritis, often presents as advanced renal failure with end-stage renal disease at diagnosis. Tubulointerstitial injury and fibrosis on histology are the most important predictors of renal outcome. A non-invasive biomarker is required for assessment of progression in IgA nephropathy. We investigated the utility of blood profibrotic molecules, TGF-β1 and miRNA-21-5p (miR-21), to identify a non-invasive biomarker for renal fibrosis in IgAN. Materials and methods: The study included 30 IgAN (mean age 31.5 ± 9 years) at the time of initial diagnosis, 25 age–sex-matched healthy controls and 10 Lupus nephritis patients as disease controls. Serum TGF-β1 was analyzed by enzyme-linked immunosorbent assay and plasma miR-21 by qRT-PCR, normalized with U6-snRNA. The levels were correlated with clinical features, laboratory parameters, histological Oxford MEST-C score and renal outcome. Results: The serum TGF-β1 and plasma miR-21 were significantly higher in patients with IgAN than in healthy controls. TGF-β1 significantly correlated with serum creatinine, eGFR, Oxford T score and miR-21. High plasma miR-21 was significantly associated with T score and interstitial inflammation. On multivariate analysis, high levels of TGF-β1 and miR-21 correlated with lower eGFR and T score, respectively. On a follow-up period of 21.5 months, high miR-21 expression at diagnosis was associated (p = 0.02) with a poor renal outcome having a shorter time to doubling of serum creatinine. Conclusion: High blood TGF-β1 and miR-21 expression at diagnosis of IgAN show significant correlation with renal function and degree of chronic tubulointerstitial injury on histology. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prognostic value of metabolic syndrome (MetS) and its relationship with renal structure changes in patients with type 2 diabetes and associated diabetic nephropathy (DN). Methods: 411 Chinese patients with type 2 diabetes and biopsy-confirmed DN were enrolled in this retrospective study. MetS was defined according to the modified criteria of the 2005 International Diabetes Federation. Baseline demographics and clinical information at the time of renal biopsy were extracted from the hospital's electronic medical records system. Renal pathological findings were assessed according to Renal Pathology Society system. Univariate and multivariate logistic regression analyses were performed to define the pathological covariates associated with MetS. A competing risk model, with death as the competing risk, was used to estimate the sub-distribution hazard ratio (SHR) of MetS for end-stage kidney disease (ESKD). Results: 224 (55%) patients had MetS. Patients with MetS had poor renal function and more severe interstitial fibrosis tubular atrophy scores (IFTA) than those without MetS. Multivariate logistic regression analysis revealed that IFTA was significantly associated with MetS (odds ratio per score increase 1.45, 95% confidence interval [CI] 1.02–2.05). Of the patients with DN at risk, 40% of patients progressed to ESKD. After adjusting for renal function and pathological parameters, the presence of MetS was an independent predictor for progression to ESKD (SHR 1.93, 95% CI 1.34–2.79). The SHRs for progression to ESKD also increased as the number of MetS components increased. Additionally, adding the IFTA scores improved the prognostic power of a model that only contained MetS and clinical covariates for predicting future ESKD. Conclusion: MetS is an independent prognostic predictor of ESKD in patients with T2D and DN, while adding the IFTA scores increased the prognostic value of MetS for renal outcome. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the application value of diffusion kurtosis imaging (DKI) for monitoring renal function and interstitial fibrosis. Methods: Forty-two patients suspected of having primary nephropathy, hypertension or diabetes with impaired renal function were examined with DKI. DKI metrics of renal cortex and medulla on both sides of each patient were measured, including mean kurtosis (MK), axial kurtosis (Ka), radial kurtosis (Kr), mean diffusivity (MD) and fractional anisotropy (FA). The differences in DKI metrics between stable and impaired estimated glomerular filtration rate (eGFR) patients as well as between mild and severe interstitial fibrosis patients were compared. Correlations of DKI metrics with clinical indicators and pathology were analyzed. Diagnostic performance of DKI to assess the degree of renal dysfunction was analyzed. Results: Cortical MK, parenchymal Ka, MD and medullary FA were different in stable vs impaired eGFR patients and mild vs severe interstitial fibrosis patients (all p <.05). Negative correlation was found between Ka and eGFR (cortex: r = − 0.579; medulla: r = − 0.603), between MD and interstitial fibrosis (cortex: r = − 0.899; medulla: r = − 0.770), and positive correlation was found between MD and eGFR (cortex: r = 0.411; medulla: r = 0.344), between Ka and interstitial fibrosis (cortex: r = 0.871; medulla: r = 0.844) (all p <.05). DKI combined with mean arterial blood pressure (MAP) and urea showed good diagnostic power for assessing the degree of renal dysfunction (sensitivity: 90.5%; specificity: 89.5%). Conclusions: Noninvasive DKI has certain application value for monitoring renal function and interstitial fibrosis. [ABSTRACT FROM AUTHOR]

Background: Rejection is responsible for just under 50% of graft loss in the pediatric kidney transplant population. Early identification and treatment of allograft injury, specifically modifiable pathologies such as subclinical rejection (SCR), calcineurin inhibitor toxicity, and BK virus nephropathy, may improve allograft survival. Protocol surveillance biopsy (SB) currently offers the earliest opportunity for targeted interventions. Methods: This is a single-center retrospective review of 215 kidney SBs obtained from 2008 to 2016 in 97 pediatric kidney transplant recipients. SBs were obtained at 6, 12, and 24 months post-transplantation. Frequency of abnormal histologic findings, estimated glomerular filtration rate at time of SB, and SB-related complications were recorded. Data were analyzed to investigate possible time trends and the presence of demographic or clinical associations with abnormal histologic findings. Results: Potentially modifiable histologic findings were seen in 38.1% of all SBs. SCR was found with increasing frequency across all time points with an estimated 49% increase in the odds of a SCR finding per additional 6 months post-transplantation (aOR 1.49, 95% CI 1.06–2.09, p = 0.022). Among follow-up biopsies in patients who underwent treatment for SCR, 50% had no SCR and 18.8% showed histologic improvement. The complication rate associated with SB was 1.9% (4/215 SBs) and consisted of only minor complications. Conclusions: SBs are safe and offer the opportunity to identify and treat modifiable histologic changes in the pediatric kidney transplant population. The performance of SBs for up to 2 years after transplantation can have meaningful clinical impact. [ABSTRACT FROM AUTHOR]

Survival time of kidney transplant patients is primarily threatened by chronic allograft dysfunction (CAD), whose typical feature is interstitial fibrosis and tubular atrophy (IF/TA). CAD could be caused by ischemia–reperfusion injury (IRI) during renal transplantation. MiR-378 is correlated with multiple kidney diseases and implicated in CAD. To clarify the underlying mechanism of miR-378 on renal allograft, we utilize renal unilateral IRI mice and H/R NRK52E cells. To evaluate the acute tubular damage, we determined the apoptotic rate by TUNEL assay and examined mice kidney sections of H&E staining 1 day after IRI. To assess the chronic renal interstitial inflammation and fibrosis, we detected the infiltration rates of CD45R+ leukocytes and Ly6b+ neutrophils by immunohistochemistry, examined mice kidney sections of picrosirius staining and measured the mRNA level of Col1a1 14 days after IRI. To investigate the H/R injury of NRK52E cells, MTT assay was performed to detect cell viability, TUNEL assay was performed to determine apoptotic rate and luciferase reporter assay was carried out to demonstrate the potential target of miR-378. Moreover, we determined the levels of miR-378 of renal allograft biopsies in healthy patients and patients diagnosed with IF/TA. We found agomir-378 treatment significantly reduced the apoptotic rate and tubular damage scores assessed by H&E staining 1 day after IRI. Agomir-378 treatment also decreased infiltration rates of both CD45R+ leukocytes and Ly6b+ neutrophils and fibrosis examined by picrosirius staining and by the mRNA level of Col1a1 14 days after IRI. Experiments in vitro revealed that miR-378 increased cell viability and decreased apoptotic rate of NRK52E cells subjected to H/R. Additionally, luciferase reporter assay confirmed that caspase 3 was targeted by miR-378 directly. Furthermore, we found the levels of miR-378 were significantly lower in renal allografts of patients with IF/TA than those of healthy controls. Taken together, we have found that miR-378 has potential protective effects on renal allografts to prevent IRI during kidney transplantation and following IF/TA of renal allografts. [ABSTRACT FROM AUTHOR]

Myocardial infarction is a clinical form of necrosis in the myocardium caused by an imbalance between the coronary blood supply and myocardial demand. Garcinol is a polyisoprenylated benzophenone found in the fruit of Garcinia indica, which is abundant in tropical regions. This fruit contains high levels of garcinol, isoxanthochymol, isogarcinol, hydroxycitric acid and xanthochymol. Garcinol and hydroxycitric acid have been shown to have antioxidant effects. In this study, rats were assigned to sham, control, low-dose, high-dose and positive control groups. Hemodynamic and apoptotic markers were evaluated, and histopathological analysis was conducted. The mRNA and protein levels of caspase-3, Bax, Bcl-2 and cleaved caspase-3 were quantified. Garcinol treatment increased the heart rate and improved the maximum rate of increase in left-ventricle (LV) pressure (+dp/dtmax), maximum rate of decrease in LV pressure (–dp/dtmax), LV ejection fraction and LV systolic pressure in rats with induced heart failure. Garcinol treatment reversed body, liver and heart weight changes, resulting in returns to near-normal levels. In the garcinol treatment group, the number of broken fibers, extent of inflammatory cell infiltration and rate of apoptosis remained within normal ranges. Garcinol reduced the cross-sectional areas of cardiomyocytes, and reduced interstitial fibrosis to a normal level. The mRNA and protein levels of cleaved caspase-3, caspase-3 and Bax were reduced, whereas those of Bcl-2 were increased, following high-dose (100 mg/kg) garcinol treatment. These findings suggest that garcinol effectively prevents apoptosis in rats with isoproterenol-induced heart failure and in cardiac H9C2 cells. [ABSTRACT FROM AUTHOR]

Background: To improve the long-term outcomes following renal transplantation, prevention of renal-allograft interstitial fibrosis (IF), mainly due to calcineurin inhibitors, is an important therapeutic target. Everolimus (EVR) was reported to have antifibrotic effects. We aimed to investigate the safety, efficacy, and IF of our modified immunosuppressive regimen, which includes early introduction of EVR and reduced-exposure tacrolimus (Tac) (EVR group), and compare it with the standard-exposure tacrolimus-based regimen (Tac group) in de novo living-donor renal recipients. Methods: In this retrospective, single-center cohort study, we compared the 2-year clinical courses between the two groups according to intention to treat. Additionally, in patients in whom biopsies were obtained at 1 h, 3 months, and 12 months post-transplant, we compared IF between the groups using imaging analysis. Results: Overall, 47 patients were included (EVR group, n = 22; Tac group, n = 25). There were no significant differences in renal function and incidences of rejection and viral infections between the groups at the 2-year post-transplant follow-up. However, pathologic imaging analysis (n = 34) revealed chronological progression of IF in the Tac group during the first year post-transplant and no changes in the EVR group (fibrosis rate at 3 months: 20.8 vs. 13.6%, p < 0.001; at 12 months: 24.7 vs. 14.7%, p < 0.001, respectively). Conclusion: Our modified immunosuppressive regimen may have an antifibrotic effect on transplanted kidneys without loss of safety and efficacy. [ABSTRACT FROM AUTHOR]

In search of a non-invasive alternative detection of early-stage cardiac allograft vasculopathy (CAV), in this preliminary study we tested the hypothesis that interstitial fibrosis quantified with cardiac magnetic resonance (CMR) can serve as a biomarker for the detection of CAV. Late-stage CAV was detected with routine X-ray coronary angiography (XRCA), while a coronary intima-media thickness ratio (IMTR) > 1 on optical coherence tomography (OCT) was used to detect early-stage CAV. Interstitial fibrosis was quantified in the endomyocardial biopsy (EMB) and indirectly with CMR as the T1 relaxation time and extracellular volume (ECV). CMR was performed within 48 h of a single invasive procedure with XRCA, OCT, and EMB procurement in stable HTx recipients (n = 27; age 54 ± 13 years, 5.4 ± 3.7 years post-transplant). XRCA-CAV and IMTR > 1 were present in 15% and 75% of study patients, respectively. The T1 relaxation times and ECV were increased in patients with XRCA-CAV (p = 0.03 each), while IMTR and EMB interstitial fibrosis were not significantly different (both p > 0.05). ECV (ρ = 0.46, p = 0.02) and IMTR (ρ = 0.58; p = 0.01) correlated with the histological quantity of interstitial fibrosis, while the T1 relaxation time (p = 0.06) did not. The correlation of the IMTR with the EMB interstitial fibrosis tentatively validates the hypothesis that interstitial fibrosis may serve as an early indicator of CAV. Moreover, the significant association of CMR-based ECV with the magnitude of interstitial fibrosis in the biopsy suggests ECV as a potential biomarker for interstitial fibrosis due to early-stage CAV. The measurement of ECV may therefore have a role for non-invasive detection and follow-up of early-stage CAV. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the risk factors of renal flare in patients with membranous lupus nephritis (class V lupus nephritis). Biopsy-proven pure membranous lupus nephritis patients diagnosed between January 1997 and September 2017 were studied. We assessed and compared the clinical and pathological parameters between patients who experienced renal flare and those who did not. To identify risk factors of renal flare, multivariable Cox proportional hazard regression analysis was performed. Out of the 53 patients with pure membranous lupus nephritis, 17 patients (32.1%) experienced renal flare during a median follow-up of 121.5 months (range 44.4–196.9). Patients who experienced renal flare had significantly higher proportion of tubulointerstitial inflammation (76.5% vs. 36.1%, p = 0.006) and tubular atrophy/interstitial fibrosis (70.6% vs. 27.8%, p = 0.003) at baseline. In multivariable Cox proportional hazard regression analysis, the presence of tubulointerstitial inflammation [adjusted hazard ratio (HR) 5.532, 95% confidence interval (CI) 1.722–17.776, p = 0.004] and tubular atrophy/interstitial fibrosis (adjusted HR 4.328, 95% CI 1.450–12.916, p = 0.009) at baseline was significantly associated with increased risk of renal flare. The presence of tubulointerstitial inflammation and tubular atrophy/interstitial fibrosis is associated with increased risk of renal flare in patients with membranous lupus nephritis. [ABSTRACT FROM AUTHOR]

Copyright of Rechtsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Interstitial fibrosis after acute myocardial infarction (MI) leads to cardiac structural remodeling and dysfunction. The peroxisome proliferator-activated receptor-gamma (PPAR-γ) agonist chrysin has been shown to protect injured myocardium through suppression of oxidative stress and inflammation. This study was designed to investigate the effect and mechanism of chrysin on myocardial fibrosis. A rat MI model was created by ligating the left coronary artery. The rats with MI were treated with chrysin (40 mg/kg/day) or 0.5% carboxymethylcellulose sodium by intragastric administration for 4 weeks after operation. The effect of chrysin on cardiac fibroblasts (CFs) were also assessed in vitro. Echocardiography showed that cardiac function was significantly improved after chrysin treatment. Chrysin reduced the levels of MDA and SOD and GSH-Px in myocardial tissue. Chrysin attenuated the interstitial and perivascular fibrosis and the expression of collagenlin the peri-infarcted zone and remarkably decreased the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9. Chrysin up-regulated PPAR-γ and inhibited the nuclear factor-kappa B (NF-κB) pathway by suppressing inhibitor kappa B kinase β phosphorylation. Immunohistochemistry analysis and PCR detected downregulated expression of AP-1 after chrysin treatment. Chrysin also markedly reduced the increased α-SMA, typeland type III collagen expression of CFs mediated by AngII in vitro. In conclusion, chrysin has an antifibrosis cardioprotective effect on the infarct peripheral zone after MI. The underlined mechanism may be the up-regulation of PPAR-γ and inhibition of the NF-κB and AP1 pathway. [ABSTRACT FROM AUTHOR]

A novel multi-organ disease that is fatal in early childhood was identified in three patients from two non-consanguineous families. These children were born asymptomatic but at the age of 2 months they manifested progressive multi-organ symptoms resembling no previously known disease. The main clinical features included progressive cerebropulmonary symptoms, malabsorption, progressive growth failure, recurrent infections, chronic haemolytic anaemia and transient liver dysfunction. In the affected children, neuropathology revealed increased angiomatosis-like leptomeningeal, cortical and superficial white matter vascularisation and congestion, vacuolar degeneration and myelin loss in white matter, as well as neuronal degeneration. Interstitial fibrosis and previously undescribed granuloma-like lesions were observed in the lungs. Hepatomegaly, steatosis and collagen accumulation were detected in the liver. A whole-exome sequencing of the two unrelated families with the affected children revealed the transmission of two heterozygous variants in the NHL repeat-containing protein 2 (NHLRC2); an amino acid substitution p.Asp148Tyr and a frameshift 2-bp deletion p.Arg201GlyfsTer6. NHLRC2 is highly conserved and expressed in multiple organs and its function is unknown. It contains a thioredoxin-like domain; however, an insulin turbidity assay on human recombinant NHLRC2 showed no thioredoxin activity. In patient-derived fibroblasts, NHLRC2 levels were low, and only p.Asp148Tyr was expressed. Therefore, the allele with the frameshift deletion is likely non-functional. Development of the Nhlrc2 null mouse strain stalled before the morula stage. Morpholino knockdown of nhlrc2 in zebrafish embryos affected the integrity of cells in the midbrain region. This is the first description of a fatal, early-onset disease; we have named it FINCA disease based on the combination of pathological features that include fibrosis, neurodegeneration, and cerebral angiomatosis. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to examine whether plasma neutrophil gelatinase-associated lipocalin (NGAL) levels predict the outcome of kidney function and correlate with the severity of tubulointerstitial damages in patients with chronic kidney disease (CKD). Methods: In this prospective 18-month cohort study of 112 patients with CKD between 2010 and 2011, associations between plasma NGAL levels and estimated glomerular filtration ratio (eGFR), further worsening of kidney function and histological lesion on kidney biopsy were investigated. Results: Serum levels of creatinine and eGFR before the study were 1.48 ± 0.65 mg/dl and 42.6 ± 22.0 ml/min/1.73 m. Median plasma NGAL level was 148.5 (83.75-248.25) ng/ml and showed no correlation with eGFR or age. 87 out of 112 patients were able to follow up for 18 months. Patients with higher levels of NGAL (>107.8 ng/ml) showed significantly more decrease in eGFR in CKD stage 1 or 2 than those with lower levels of NGAL (≦107.8 ng/ml), while there was no difference in change in eGFR in CKD stage 3-5 between patients with higher and lower levels of NGAL. In the kidney biopsy of 27 patients out of enrolled patients, plasma NGAL levels correlated significantly with the degree of interstitial cell infiltration and fibrosis, but did not correlate with that of glomerular sclerosis. In ROC analysis, plasma NGAL levels predicted tubulointerstitial cell infiltrations more accurately [AUC = 0.8300 than eGFR (AUC = 0.716)]. Conclusion: Plasma NGAL is a useful marker of interstitial lesions in patients with CKD and a predictor of further kidney worsening in the early CKD stage. [ABSTRACT FROM AUTHOR]

Background: The discovery of circulating microRNAs (miRNAs), as potential noninvasive diagnostic biomarkers, has opened new avenues of research for identifying patients with chronic failure in renal transplantation. The present study aimed to investigate the expression levels of four immune-related miRNAs (miR-21, miR-31, miR-142-3p and miR-155) in plasma samples of renal recipients. Methods: The plasma expression levels of the miRNAs were evaluated by quantitative real-time PCR (qPCR) in 53 renal recipients with long-term stable allograft function, SGF ( N = 27), and with biopsy-proven interstitial fibrosis and tubular atrophy (IFTA) ( N = 26) and also healthy controls ( N = 15). The possible correlation between clinical parameters and the circulating miRNAs and the receiver-operating characteristic (ROC) analysis were performed. Results: Our results showed that expression of miR-21 ( p = 0.023), miR-142-3p ( p = 0.048) and miR-155 ( p = 0.005) was significantly upregulated in plasma samples of recipients with IFTA in comparison with SGF and healthy control groups. Concentration of miR-21 (∆Ct value) in plasma was negatively correlated with creatinine ( r = −0.432, p = 0.028) and positively correlated with eGFR ( r = 0.423, p = 0.031). The multivariate ROC curve analysis indicated that miR-21, miR-142-3p and miR-155 in plasma samples could discriminate almost most of the IFTA patients (area under curve = 0.802, sensitivity = 81%, specificity = 92%). Conclusion: Our data suggested that altered expression of miR-21, miR-142-3p and miR-155 in plasma samples may be associated with renal dysfunction and can be used for graft monitoring. [ABSTRACT FROM AUTHOR]

Renal fibrosis is an important factor for end-stage renal failure. However, only few therapeutic options for its treatment are established. Zaprinast, a phosphodiesterase 5 inhibitor, and serelaxin, the recombinant form of the naturally occurring hormone relaxin, are differently acting modulators of cyclic guanosine monophosphate (cGMP) signaling. Both agents enhance cGMP availability in kidney tissue. These substances alone or in combination might interfere with the development of kidney fibrosis. Therefore, we compared the effects of combination therapy with the effects of monotherapy on renal fibrosis. Renal fibrosis was induced by unilateral ureteral obstruction (UUO) for 7 days in wild-type (WT) and cGKI knockout (KO) mice. Renal antifibrotic effects were assessed after 7 days. In WT, zaprinast and the combination of zaprinast and serelaxin significantly reduced renal interstitial fibrosis assessed by α-SMA, fibronectin, collagen1A1, and gelatinases (MMP2 and MMP9). Intriguingly in cGKI-KO, mRNA and protein expression of fibronectin and collagen1A1 were reduced by zaprinast, in contrast to serelaxin. Gelatinases are not regulated by zaprinast. Although both substances showed similar antifibrotic properties in WT, they distinguished in their effect mechanisms. In contrast to serelaxin which acts both on Smad2 and Erk1, zaprinast did not significantly diminish Erk1/2 phosphorylation. Interestingly, the combination of serelaxin/zaprinast achieved no additive antifibrotic effects compared to the monotherapy. Due to antifibrotic effects of zaprinast in cGKI-KO, we hypothesize that additional cGKI-independent mechanisms are supposed for antifibrotic signaling of zaprinast. [ABSTRACT FROM AUTHOR]

The longstanding focus in chronic kidney disease (CKD) research has been on the glomerulus, which is sensible because this is where glomerular filtration occurs, and a large proportion of progressive CKD is associated with significant glomerular pathology. However, it has been known for decades that tubular atrophy is also a hallmark of CKD and that it is superior to glomerular pathology as a predictor of glomerular filtration rate decline in CKD. Nevertheless, there are vastly fewer studies that investigate the causes of tubular atrophy, and fewer still that identify potential therapeutic targets. The purpose of this review is to discuss plausible mechanisms of tubular atrophy, including tubular epithelial cell apoptosis, cell senescence, peritubular capillary rarefaction and downstream tubule ischemia, oxidative stress, atubular glomeruli, epithelial-to-mesenchymal transition, interstitial inflammation, lipotoxicity and Na/H exchanger-1 inactivation. Once a a better understanding of tubular atrophy (and interstitial fibrosis) pathophysiology has been obtained, it might then be possible to consider tandem glomerular and tubular therapeutic strategies, in a manner similar to cancer chemotherapy regimens, which employ multiple drugs to simultaneously target different mechanistic pathways. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate if specific clinical and histological findings can be related to biopsy complications to enable more closely monitoring patients at high risk. Methods: Results from 1081 biopsies (994 patients, median age 54.5 years; 896 native and 185 transplant kidney biopsies) were included. Diagnostic quality, morphology, clinical data and complications were prospectively registered. Results: In native kidney biopsies, the most common diagnosis was IgA-nephritis, while in transplant kidney biopsies it was rejection. Patients with IgA-nephritis had a higher risk of major complications (11.7 versus 6.4 %, Odds Ratio (OR) 1.8, Confidence Interval (CI) 1.1-3.2) when compared to patients with other diseases. In native kidney biopsies, patients who experienced major complications had higher degrees of glomerulosclerosis (31 versus 20 %, p = 0.008), whereas in transplant kidney biopsies, patients had higher degrees of interstitial fibrosis (82 versus 33 %, p < 0.001) when compared to patients without major complications. IgA-nephritis-patients had a higher risk of re-biopsies (4.7 versus 1.3 %, OR 4, CI 1.5-11) than patients with other diseases. Patients with native kidneys who needed re-biopsies were younger (42.6 versus 52.3 years, p = 0.031) and had a higher degree of interstitial fibrosis (63 versus 34 %, p = 0.046). Conclusions: Patients with IgA-nephritis have an increased risk of major biopsy complications. The risk of re-biopsies was higher in younger individuals and in patients with IgA-nephritis. [ABSTRACT FROM AUTHOR]

Background and aim: The infusion of chronic angiotensin II (Ang II) has been shown to promote renal interstitial fibrosis. To evaluate the pathophysiological significance of the natriuretic peptide-GC-A system, we infused Ang II (1.0 mg/kg/day) in GC-A-deficient mice (GC-A-KO). Methods: We used 5 groups (Wild-Saline n = 12, Wild-Ang II n = 14, GC-A-KO-Saline n = 11, GC-A-KO-Ang II n = 13, and GC-A-KO-Ang II-Hydralazine n = 10). Saline or Ang II was infused subcutaneously using an osmotic minipump for 3 weeks. Hydralazine was administered orally (0.05 g/L in drinking water). Results: Systolic blood pressure was significantly higher in the GC-A-KO-Saline group (130 ± 12 mmHg) than in the Wild-Saline group (105 ± 30 mmHg), and was similar to that in the Wild-Ang II (141 ± 17 mmHg) and GC-A-KO-Ang II-Hydralazine (140 ± 20 mmHg) groups. Systolic blood pressure was significantly higher in the GC-A-KO-Ang II group (159 ± 21 mmHg) than in the 4 other groups. Renal tubular atrophy and interstitial fibrosis were significantly more severe in the GC-A-KO-Ang II group (atrophy 13.4 %, fibrosis 12.0 %) than in the Wild-Saline (0, 2.0 %), Wild-Ang II (2.9, 4.4 %), and GC-A-KO-Saline (0, 2.6 %) groups. Hydralazine could not inhibit this aggravation (GC-A-KO-Ang II-Hydralazine 13.5, 11.3 %). The expression of monocyte chemotactic protein-1 in tubular cells, and F4/80 and alpha-smooth muscle actin in the interstitium was clearly detected in the Ang II-infused wild and GC-A-KO groups and was associated with renal tubular atrophy and interstitial fibrosis. The expression of E-cadherin in tubular cells was absent in the Ang II-infused wild and GC-A-KO groups and was associated with renal tubular atrophy. Conclusions: The natriuretic peptide-GC-A system may play an inhibitory role in Ang II-induced renal tubular atrophy, interstitial fibrosis, and phenotypic transformation in renal tubular cells and fibroblasts. [ABSTRACT FROM AUTHOR]

Inactivation of poly(ADP-ribose) polymerase 1 (PARP1) has been found to be protective in several disease models; however, the role of PARP1 in acute kidney injury-induced interstitial fibrosis has not been studied. Herein, we tested whether PARP1 inactivation by treatment with PJ34 (a PARP1 inactivator; 10 mg/kg body weight/day, intraperitoneal implantation of a miniosmotic pump at 2 days after the onset) contributed to the decrease in interstitial fibrosis induced by ischemia-reperfusion injury (IRI) in mouse kidneys. IRI increased PARP1 activation represented by poly(ADP-ribose) expression from 4 to 16 days postinjury, whereas treatment with PJ34 at 2 days after the onset efficaciously abolished the increase in PARP1 activation at 4, 8 and 16 days after IRI. Pharmacological inactivation of PARP1 significantly reduced interstitial fibrosis as represented by the collagen deposition and transforming growth factor-β1 level at 8 and 16 days after IRI. Consistent with collagen deposition, myofibroblast activation represented by α-smooth muscle actin expression was also reduced by PARP1 inactivation at 8 and 16 days after IRI. Furthermore, IRI enhanced macrophage influx, but PARP1 inactivaton remarkably reduced macrophage influx for 4 through 16 days after the injury. Among the chemoattractants for monocytes/macrophages and neutrophils, monocyte chemotactic protein-1 (MCP-1) production in IRI kidneys was significantly reduced by PARP1 inactivation from 4 to 16 days postinjury. These data demonstrate that PARP1 activation contributes to IRI-induced MCP-1 production and in turn to macrophage influx, resulting in the promotion of interstitial fibrosis. [ABSTRACT FROM AUTHOR]

Cardiac repair and remodeling occur following myocardial infarction (MI). Our previous study demonstrated that platelet-derived growth factor (PDGF)-A/-D and PDGF receptors (PDGFR) are increased in the infarcted heart, with cells expressing PDGFR primarily endothelial and fibroblast-like cells. In the present study, we tested the hypothesis that PDGF contributes to cardiac angiogenesis and fibrogenesis post-MI. Rats with experimental MI were treated with either a PDGFR antagonist (Imatinib, 40 mg/kg/day) or vehicle by gavage, and sham-operated rats served as the controls. Cardiac fibrogenesis, angiogenesis, and ventricular function were detected at weeks 1 and 4 post-MI. We found that (1) transforming growth factor (TGF)-β1, tissue inhibitors of metalloproteinases (TIMP)-1/-2, and type I collagen mRNA were all significantly increased in the infarcted heart at week 1 post-MI, while PDGFR blockade significantly reduced these fibrogenic mediators in the noninfarcted myocardium as compared to controls; (2) fibrosis developed in both the infarcted and noninfarcted myocardium at week 4 with PDGFR blockade significantly suppressing collagen volume in the noninfarcted myocardium; (3) angiogenesis was activated in the infarcted myocardium, particularly at week 1, and was not altered by treatment with imatinib; and (4) ventricular dysfunction was evident in MI rats at week 4, and mildly improved with imatinib treatment. These observations indicated that PDGF can contribute to the development of cardiac interstitial fibrosis in the noninfarcted myocardium, but does not alter scar formation in the infarcted myocardium. Further, this study suggests the potential therapeutic effects of PDGFR blockade on interstitial fibrosis of the infarcted heart. [ABSTRACT FROM AUTHOR]

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Copyright of Der Nephrologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study was to investigate the expression and significance of integrin-linked kinase (ILK) in the pathogenesis of chronic allograft nephropathy (CAN) in rats. For this, kidneys of Fisher (F344) rats were orthotopically transplanted into Lewis (LEW) rats. The animals were evaluated at 4, 8, 12, 16, and 24 weeks post-transplantation for renal function and histopathology. ILK protein expression was determined by Western-blot and immunohistological assays, and mRNA by RT-PCR. Our data show that 24-h urinary protein excretion in CAN rats increased significantly at week 16 as compared with F344/LEW controls. Allografts showed markedly increased mononuclear cells infiltration and presented with severe interstitial fibrosis and tubular atrophy at 16 and 24 weeks. ILK expression (protein/mRNA) was upregulated in rat kidneys with CAN, and the increase became more significant over time after transplantation. ILK expression correlated significantly with 24-h urinary protein excretion, serum creatinine levels, tubulointerstitial mononuclear cells infiltration, smooth muscle cells (SMCs) migration in vascular wall, and interstitial fibrosis. Therefore, it was concluded that ILK overexpression was the key event that involved mononuclear cells infiltration and vascular SMCs migration at early stage, and interstitial fibrosis and allograft nephroangiosclerosis at later stage of CAN pathogenesis in rats. [ABSTRACT FROM AUTHOR]

Copyright of Der Nephrologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study was to analyse the outcome and its influencing factors in patients whose therapy was converted from calcineurin inhibitors (CNI) to sirolimus (SRL) due to chronic allograft nephropathy (CAN). Therapies of 78 patients (44 men) with CAN from three European transplant centres were converted from CNI therapy to SRL and followed 24 months. Slopes for creatinine clearance before and after conversion were calculated. Influencing factors were analysed by a multivariance analysis. The slope of the creatinine clearance improved significantly (−0.90 vs. −0.34 ml min−1 month−1; p < 0.01). In patients whose therapy was converted from cyclosporine A (CyA) to SRL, the slope improved significantly, whereas conversion from Tacrolimus (Tac) to SRL did not affect the slope. The benefit was more pronounced in (1) patients with low or moderate baseline creatinine clearance, (2) patients receiving SRL after conversion without additional mycophenolate mofetil and (3) patients with low or moderate proteinuria. Conversion from CyA to SRL but not from Tac to CRL is associated with a reduced loss of renal allograft function in patients with CAN. [ABSTRACT FROM AUTHOR]

Chronic lesions in renal biopsies are a well recognized prognostic factor for renal diseases, including lupus nephritis. The methods used for assessment of chronic lesions are, however, largely based on semiquantitative evaluation and may lead to poor reproducibility. Interobserver variation is particularly important in lupus nephritis, in which acute and chronic lesions may occur simultaneously. In this study we tested the reproducibility of chronic lesion assessment performed by three pathologists, two with specific training in renal pathology, using 20 renal biopsies and a standard semiquantitative method. In a second experiment, we evaluated the reproducibility of chronic lesion assessment in 33 biopsies of lupus nephritis by the two nephropathologists. The semiquantitative estimated values were compared with those from a previously proposed morphometric method for quantification of chronic lesions in renal biopsies. Although correlations were observed among the estimated values, there was a wide range of variation when semiquantitative methods were used. In particular, activity and chronicity indices of lupus nephritis were poorly reproducible. In contrast, use of a morphometric score, although not eliminating interobserver variability, led to better reproducibility of estimated values than that obtained with semiquantitative methods. [ABSTRACT FROM AUTHOR]

Mast cell-derived chymase is an angiotensin II-forming enzyme that appears to be involved in tubulointerstitial fibrosis in the kidneys. Previous studies have shown that the level of chymase increases in grafted kidneys after rejection and in adult patients with diabetic nephropathy. However, the significance of chymase in children with renal diseases has not been investigated. Using immunohistochemistry, we have investigated chymase expression in biopsy samples of renal tissue from 104 children with kidney diseases, including rapidly progressive crescentic glomerulonephritis ( n = 3), diabetic nephropathy ( n = 2), allografted kidney ( n = 3), membranoproliferative glomerulonephritis ( n = 6), immunoglobulin A nephropathy ( n = 33) and Henoch–Schönlein purpura nephritis ( n = 23). Increased numbers of chymase-positive mast cells were observed in the renal cortex of all three patients with crescentic glomerulonephritis (mean 26.0/mm2; range 19.3–36.8/mm2). Chymase-positive cells were also observed in the renal biopsy of an allografted kidney and in those from children with diabetic nephropathy. The mean number of chymase-positive cells in renal tissue samples characterized by each renal disease was significantly correlated with the mean intensity of the interstitial fibrosis in that same tissue sample (Spearman’s rank correlation test p = 0.0013; rank correlation coefficient 0.84). These findings suggest that mast cell-derived chymase plays an important role in juvenile crescentic glomerulonephritis. [ABSTRACT FROM AUTHOR]

Adenine phosphoribosyltransferase deficiency in mice or an excessive oral intake of adenine leads to the accumulation of 2,8-dihydroxyadenine (DHA) in renal tubules and that causes progressive renal dysfunction accompanied by interstitial fibrosis. However, the precise mechanism responsible for DHA-induced progressive fibrosis is not fully understood. The present study investigates the possible involvement of monocytes/macrophages in the progressive fibrosis induced by feeding adenine to mice. Urinary calculi were deposited in tubules on day 7 after the initiation of adenine feeding. Elevation of the serum creatinine level and loss of body weight were observed in a time-dependent manner, suggesting the development of typical renal dysfunction induced by the adenine feeding. In renal tissue, mRNA expression of MCP-1, MIP-1α, RANTES, IL-1β, CCR2, TGF-β, α-smooth muscle actin (α-SMA) and collagen 1a1 was increased in parallel. Along with the increased expression of these genes, a remarkable infiltration of macrophages into the tubulointerstitial area was observed in a time-dependent manner. In addition, in the tubulointerstitial area, α-SMA positive fibroblasts were increased in parallel with collagen deposition. These results suggest that the excessive consumption of adenine leads to progressive renal dysfunction in mice. We speculate that the accumulation of DHA in tubules might stimulate epithelium to produce MCP-1 and that profibrogenic TGF-β produced by infiltrated macrophages might stimulate interstitial fibroblasts to produce collagen. These results indicate that macrophage infiltration is one of the triggers that initiates interstitial fibroblast activation and collagen deposition followed by renal dysfunction. [ABSTRACT FROM AUTHOR]

A 52-year-old Japanese female was admitted to our hospital for microhematuria, proteinuria and progressive renal dysfunction. Two years prior to admission, she was diagnosed with lung adenocarcinoma and multiple bone and brain metastases, and was treated with gefitinib (250 mg/day). Treatment for 6 months induced partial response with 30% regression of the primary lung tumor, and resolution of metastatic tumors. After confirmation of the partial remission state, we performed percutaneous renal biopsy. Glomeruli showed mild to moderate mesangial proliferation, segmental endocapillary proliferation and occasional fibrocellular crescent formation. In addition, severe interstitial fibrosis and tubular atrophy relative to the degree of glomerular sclerosis were noted. Immunofluorescence microscopy showed predominant IgA deposition in the mesangial area. Electron microscopy revealed subepithelial and paramesangial electron-dense deposits. In consideration of the prognosis of lung cancer and complication of immunosuppressive treatment, we continued gefitinib only and closely followed-up the clinical course in the outpatient clinic. Sixteen months later, she continued to have proteinuria and microhematuria, and the severity of renal dysfunction was still the same. However, the lung cancer started to increase in size. This is quite an unusual case presenting histologically with tubulointerstitial nephritis and IgA nephropathy in a patient on long-term treatment with gefitinib. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) occurs in all age groups, including children. Regardless of the underlying cause, CKD is characterized by progressive scarring that ultimately affects all structures of the kidney. The relentless progression of CKD is postulated to result from a self-perpetuating vicious cycle of fibrosis activated after initial injury. We will review possible mechanisms of progressive renal damage, including systemic and glomerular hypertension, various cytokines and growth factors, with special emphasis on the renin–angiotensin–aldosterone system (RAAS), podocyte loss, dyslipidemia and proteinuria. We will also discuss possible specific mechanisms of tubulointerstitial fibrosis that are not dependent on glomerulosclerosis, and possible underlying predispositions for CKD, such as genetic factors and low nephron number. [ABSTRACT FROM AUTHOR]

Background. In clinicopathological studies of cellular remodeling in the progression of diabetic nephropathy, it has not been well described whether tissue macrophage numbers and the expression of two cytoskeletal proteins – α- smooth muscle actin (αSMA) and vimentin – correlate with the disease severity. Methods. Renal biopsy specimens from 23 patients with noninsulin-dependent diabetes mellitus (NIDDM) were examined by immunoperoxidase methods for CD68+ macrophages and αSMA and vimentin staining in paraffinembedded samples. αSMA staining was evaluated in mesangial and interstitial myofibroblastic cells, and vimentin staining was evaluated in podocytes and mesangial and tubular cells. Results. Glomerular macrophage numbers were not correlated with any clinicopathological scores. However, the interstitial macrophage score was significantly correlated with serum creatinine (sCr) and strongly correlated with the interstitial fibrosis score. Both αSMA and vimentin were detectable in the mesangium, without significant correlation with each other. A positive correlation was observed between mesangial αSMA and urinary (u-) protein levels. In contrast, an inverse correlation was observed between levels of mesangial vimentin and u-protein. Mesangial αSMA, but not vimentin, showed a significant correlation with glomerular sclerosis. Podocytic vimentin levels tended to decrease in patients with higher sCr levels. The severity of interstitial peritubular αSMA was correlated strongly with interstitial macrophage proliferation and significantly with the interstitial fibrosis score. Conclusions. The expression of mesangial αSMA may play a role in the progression of glomerular damage, while, on the other hand, newly acquired mesangial vimentin seems to be attenuated by heavy proteinuria. In addition, it was suggested that peritubular αSMA-positive myofibroblastic cells, in collaboration with interstitial macrophages, contribute to the progression of interstitial fibrosis in diabetic nephropathy. [ABSTRACT FROM AUTHOR]

We measured plasma concentrations of TGF-beta 1 in patients with obstructive ureteral calculi and compared them with the plasma concentrations of healthy volunteers. The present study was a prospective study containing a homogenous group of patients with unilateral ureteral obstruction (UUO). The study consisted of patients with ureteral stones less than 7 mm in diameter that caused mild to moderate obstruction. All patients were referred by the emergency department of our hospital and examined between April 2003 and April 2004. The presence and characteristics of both stone and obstruction were determined by plain abdominal x-ray and gray-scale ultrasonography (US). Blood samples were collected from both patients and control individuals on admission and 1 week after conservative follow-up. The plasma TGF-beta 1 concentration was determined using a quantitative sandwich enzyme immunoassay specific for TGF-beta 1. There were 35 patients with 20 women and 15 men (average age 26.8±5.9 years), and 15 volunteers in the control group, with nine women and six men (average age 24.2±4.5 years). Average stone size was 5.6 mm±1.2 mm (range 3.5–7) for the patient group. US showed the presence of mild hydronephrosis in 24 and moderate hydronephrosis in 11 patients. Plasma concentrations of TGF-beta 1 in patients with ureteral obstruction (1,117±5.8 ng/ml, range 36–2,442 ng/ml) were significantly higher than those in the healthy control group (32±4 ng/ml) on admission ( P<0.001). There was a significant increase in TGF-beta 1 plasma concentrations in the patient group (33,525±6.8 ng/ml, range 1,107–73,288 ng/ml) after 1 week follow-up ( P<0.001). Ureteral obstruction increases plasma TGF-beta 1 concentrations in patients with ureteral stones as in UUO models in animal studies. A concomitant treatment with an anti-fibrotic agent may reduce the incidence of renal injury during obstruction. [ABSTRACT FROM AUTHOR]

This study was undertaken to investigate the effect of taurine on the infiltration of macrophages and the progression of renal interstitial fibrosis in the kidneys of rats treated with cisplatin (CDDP). Male rats in different groups were treated as follows: (1) saline as control, (2) CDDP and (3) CDDP plus taurine in drinking water. At weeks 2, 4 and 6 after the fifth CDDP injection, we examined platinum content, the kinetics of macrophages and the areas of fibrosis. In the histologic analyses, fibrotic areas were found to have developed around dilated or atrophic tubules in the corticomedullary junction in the kidneys of CDDP-treated rats, while CDDP-plus-taurine-treated rats showed a reduction of the extent and magnitude of damage. These findings reflect the fact that the percentage of fibrotic areas in the kidney of CDDP-plus-taurine-treated rats was significantly lower than in that of CDDP-injected rats throughout the recovery period (P<0.05). Compared with normal rats, the macrophages in CDDP-injected rats showed significant increases in number at weeks 2, 4 and 6 (P<0.05). In contrast, the number of macrophages in CDDP-plus-taurine-treated rats was significantly smaller than that of CDDP-injected rats. These results suggested that taurine suppressed the increase of infiltrating macrophages, and led to the attenuation of renal interstitial fibrosis (P<0.05). [ABSTRACT FROM AUTHOR]

An increased number of mast cells (MCs) is found in renal specimens of patients with diseases associated with persistent chronic inflammation. MCs proliferation is partly dependent on the presence of T lymphocytes. Both chronic inflammation and T-lymphocytes are essential in the development of chronic rejection (CR), and probably for the infiltration of MCs. MC-derived products such as heparin, histamine, and serine proteases may be responsible for endothelial proliferation and excess collagen production by fibroblasts. In this study, a quantitative evaluation of the MCs infiltration in kidney allografts with CR is performed. The extent of renal fibrosis was analysed in samples stained with Masson's trichrome. To evaluate the potential relationship between MCs and fibrosis in CR we analysed 30 kidneys with CR (25 from nephrectomies and 5 from autopsies). Ten transplanted kidneys obtained from patients died by causes not related with rejection were used as controls. CR was graded according to the Banff schema, which assesses the degree of vasculopathy, tubular atrophy, interstitial fibrosis and transplantation glomerulopathy. Giemsa-stained sections and immunohistochemistry using anti-MC tryptase and c-kit monoclonal antibodies were used to detect MCs. The mean number of MCs per 20 high-power fields (HPF) in the transplanted kidney with CR was 101.8+/-15.3 in the renal cortex and 46.60+/-6.52 in the medulla. MCs were significantly more numerous in CR with respect to normal kidneys, both in the cortex (P<0.01; Mann-Whitney U test) and in the medulla (P<0.01; Mann-Whitney U test). There was a positive correlation between the number of MCs and extent of fibrosis (P<0.01; Kruskal-Wallis one-way anova test) and tubular atrophy (P<0.01). These results suggest that MCs may play a role in the process of development of interstitial fibrosis in CR. [ABSTRACT FROM AUTHOR]

Partial obstruction of the upper urinary tract, a frequent challenge for the pediatric urologist, leads to renal damage, if deobstruction is delayed. Several but sometimes unsatisfactory animal models have been developed to study this phenomenon. Obstruction created by surgical manipulation lacks adequate correlation with a developing congenital obstruction. In some animals with congenital hydronephrosis, evidence of renal obstruction is absent. A study of the renal morphology of rats with hereditary unilateral hydronephrosis has exhibited clear evidence of renal obstruction distinguishable from renal dilatation. The renal mRNA expression of renin and transforming-growth factor- β1 (TGF-β1) was measured by a semiquantitative RT-PCR technique. In hydronephrotic kidneys, a marked loss of parenchyma, atrophy and dilation of tubuli and collecting ducts and interstitial fibrosis was observed. The mRNA expression of renin was increased significantly in comparison to controls, whereas the contralateral kidneys showed renin activity below control levels. TGF-β1 expression was markedly increased in hydronephrotic kidneys, whereas contralateral kidneys did not differ significantly from control values. These data suggest the presence of renal obstruction and not only renal dilatation in these rats with congenital hydronephrosis. This colony seems to be a representative animal model to study congenital renal obstruction even in the fetal period without the need of surgical manipulation. [ABSTRACT FROM AUTHOR]

The current study was designed to investigate possible effects of the platelet-derived growth factor (PDGF) receptor kinase blocker AG1295 on the development of interstitial fibrosis in rats with unilateral ureteral obstruction (UUO), monitored by ED-A+ fibronectin expression, the number of macrophages, and the presence of myofibroblasts as visualized by immunohistochemistry with monoclonal antibodies (mAb) IST9, mAb ED1, and mAb 1A4, respectively; interstitial fibrosis was quantified by Sirius-Red staining and computer-aided image analysis. Without AG1295 treatment, the Sirius-Red stained area of the control kidneys comprised 6.8±1.3% of the totally inspected area and increased to 19.0±1.9% in animals by 14 days and to 23.4±1.7% by 21 days after UUO. The number of macrophages increased from 4.3±1.1 in controls to 16.6±2.6 in animals at 14 days and to 23.2±4.4 at 21 days after UUO. This was accompanied by an increase in both ED-A+ fibronectin deposition and α-smooth muscle actin expression. Treatment with AG1295 (12 mg/kg body weight, daily i.p.) significantly reduced interstitial fibrosis as verified by a smaller Sirius-Red stained area (15.7±1.9% in animals at 14 days and 17.0±0.7% at 21 days after UUO) and also by a reduced number of macrophages (12.8±1.4 in animals at 14 days and 15.5±3.8 at 21 days after UUO), and by the ED-A+ fibronectin deposition and the number of cells positive for α-smooth muscle actin. The study indicates that the PDGF receptor kinase blocker AG1295 is able to decrease interstitial fibrosis in the rat UUO model significantly. The diminution of early fibrosis mediators, i.e., macrophages, ED-A+ fibronectin, and myofibroblast phenotype, points to a modulated fibrosis process via a blockade of PDGF actions. [ABSTRACT FROM AUTHOR]

Background. A 47-kDa heat-shock protein (HSP47) is a major collagen-binding stress protein and is assumed to play an important role in the fibrotic process, but its role in cisplatin-induced tubulointerstitial fibrosis is not yet clear. To explore the possible role(s) of collagen-binding stress protein HSP47 in cisplatin-induced tubulointerstitial fibrosis, the expression of HSP47 was examined in cisplatin-treated rat kidneys. Methods. Eighteen male Wistar rats were divided into two groups; group I were age-matched controls and group II, animals were injected intraperitoneally with a single dose of cisplatin (6 mg/kg body weight). One hour after cisplatin injection, three rats from group II were killed along with control rats. The remaining rats in both groups were killed on the 7th, 14th, and 28th days of the experiment and the kidneys were collected for morphological and immunohistochemical study. The expression of collagen-binding HSP47 with various proteins implicated in phenotypic modulation (α-smooth muscle actin and vimentin) and fibrosis (type I and type III collagens) was examined in control and cisplatin-treated kidneys. Results. Cisplatin induced marked tubulointerstitial damage, including interstitial fibrosis, which was characterized by increased deposition of type I and type III collagens. Increased expression of HSP47 was also noted in and around the expanded interstitium in cisplatin-treated rats; by double-staining, HSP47-expressing cells were found to be α-smooth muscle actin-positive myofibroblasts and vimentin-positive tubular epithelial cells. In addition, colocalization of HSP47 and collagens was seen in and around the interstitial fibrosis in cisplatin-treated kidneys. Conclusion. From the results, we concluded that overexpression of HSP47 by phenotypically altered renal cells may play an important role in the excessive assembly of collagens and could thereby contribute significantly to the development of the tubulointerstitial fibrosis found in cisplatin-treated rat kidneys. [ABSTRACT FROM AUTHOR]

Background. The prognosis of IgA nephropathy (IgAN) varies according to the patient's age. It usually affects children or young adults. However, the onset age for IgAN may be at middle-age or older. The influence of onset age on the clinical and renal histological findings of adult IgAN was investigated. Methods. We selected 39 IgAN patients in whom renal biopsy was performed within 2 years from the onset. The patients were divided into two groups according to onset age; early-onset group (under 35 years; group E) and late-onset group (over 35 years; group L). The clinical and histological findings and the response to steroid therapy were compared in the two groups. Results. (1) Clinically, the levels of proteinuria and hematuria in groups E and L were not different, but the creatinine clearance was lower in group L than in group E. Hypertension was frequent in group L (66.7%), but not in group E. (2) Histologically, the rate of glomerular obsolescence and the grades of interstitial fibrosis and arterio- and arteriolosclerosis were more advanced in group L than in group E. However, there were no differences in the grade of mesangial cell proliferation or mesangial matrix increase, nor were the rates of glomerular crescent and tuft adhesion formation different between the two groups. (3) The reduction of proteinuria and hematuria after 1-year steroid therapy was similar in the two groups. Conclusion. Onset age does not affect the severity of glomerular lesions and the effect of steroid therapy in the early phase of adult IgAN. However, advanced interstitial fibrosis and arterio- and arteriolosclerosis, which may be related to hypertension or the aging process, lead to impaired renal function in late-onset IgAN patients. [ABSTRACT FROM AUTHOR]

Morphometric investigations were performed in 18 biopsies from 16 patients with the nephrotic syndrome and 10 biopsies from 10 patients with mild proteinuria not associated with oedema. All biopsies showed normal glomeruli on light microscopy. The interstitial fibrosis was significantly increased in both patient groups compared with controls, and it was greater in the patients with mild proteinuria than in the group with nephrotic syndrome. A significant negative correlation was present between the degree of fibrosis and renal function in both groups of patients. [ABSTRACT FROM AUTHOR]

In different grades of MPGN with normal serum creatinine concentrations a statistical correlation exists between the cortical interstitial volume and the decreasing creatinine clearance. That means that even in the case of a serum creatinine concentration up to 1.2 mg%/100 ml the cortical interstitium may be broadened (up to 30 Vol%) and the creatinine clearance markedly reduced (up to 20 ml/min/1.73 m) (compare Fischbach et al., 1977). No significant differences could be established between the means of the serum creatinine concentration, creatinine clearance and relative interstitial volume in the four grades of severity. Only slight fibrosis in the cortical interstitium leads to an impairment of the GFR. Severe glomerular lesions, however, (grade III and IV) may occur with normal serum creatinine concentration and with normal creatinine clearance provided that the interstitium is not enlarged. It is conceivable that interstitial fibrosis leads, by a narrowing of the postglomerular vessels, to an elevated effective filtration pressure and to a slowing of glomerular blood flow and reduction of the GFR. In most cases tubules in fibrotic areas are atrophic - due to ischaemic changes and/or 'inactivity'. The resorptive capacity of these tubules could be disturbed and the GFR reduced by the so-called 'Thurau-Mechanism'. The enormous functional reserve capacity of the glomeruli, however, prevents an impairment of the GFR even in the case of severe glomerular lesions. [ABSTRACT FROM AUTHOR]

48 cases of renal amyloidosis (grade I-IV) were investigated morphologically (point-counting method). Statistically significant positive correlations exist between relative interstitial volume and serum creatinine concentration at the time of biopsy. In amyloidosis there are furthermore connections (positive rank correlations) between the extent of glomerular amyloidosis and renal insufficiency, although single cases of grade III show normal serum creatinine concentrations if the interstitium is not enlarged. With regard to interstitial alterations only fibrosis, not amyloid masses, seems to influence renal function, especially in the case of predamaged glomeruli (grade II to IV). The diminished renal function - reduction of the glom. filtr. rate - may be explained in the case of interstitial fibrosis by slowing of renal blood flow caused by a decreasing cross-sectional area of postglomerular vessels. Renal insufficiency seems to depend upon both the glomerular and the interstitial factor, but in grades II-IV the interstitial fibrosis is thought to be of more importance for renal function. [ABSTRACT FROM AUTHOR]

Morphometric investigations in 40 patients suffering from perimembranous glomerulonephritis at different stages showed that there is no certain relationship between the severity of glomerular lesions and the serum creatinine level. In 19 cases in stages I-III, with serum creatinine level less than 1.2 mg/100 ml on biopsy, the renal interstitium was less enlarged than in 21 cases in the same stages, but with serum creatinine level higher than 2 mg/100 ml. There is a significant positive correlation between the relative interstitial volume and the level of serum creatinine. The best congruence was demonstrated in the lin/log-plotting indicating that our values correlate best with an exponential function. We therefore conclude that in perimembranous glomerulonephritis, generally considered to be a glomerular disease, functional impairment cannot be explained by the glomerular lesions alone; interstitial changes have also to be taken into account as a cause of renal insufficiency. The following hypothesis is proposed; that the increase in renal interstitium and possible shrinking of collagen fibres may lead to a narrowing of intertubular capillaries. This may result in slowing of glomerular blood flow and may lead to renal insufficiency. [ABSTRACT FROM AUTHOR]

A retrospective study was conducted to evaluate the efficacy of plasmapheresis in combination with different immunosuppressive drugs ('pulse' therapy, azathioprine or cyclophosphamide together with steroids) in nine patients presenting with rapidly progressive glomerulonephritis (RPGN) not mediated by antibody to glomerular basement membrane. Six of these patients had to be initially dialysed. All patients underwent renal biopsy, which revealed that seven patients had a minimum of 80% crescents and five had interstitial fibrosis. Recovery of renal function was observed in seven patients (78%). All patients without interstitial fibrosis were recompensated for at least 14 months after the acute onset of RPGN. Those who presented with interstitial fibrosis declined to endstage renal failure after 13 months requiring chronic hemodialysis treatment or cadaveric kidney transplantation. On the basis of these findings interstitial fibrosis seems to be a limiting factor for the prognosis of non-anti-GBM-antibody mediated RPGN. [ABSTRACT FROM AUTHOR]

Copyright of Klinische Wochenschrift is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Klinische Wochenschrift is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Klinische Wochenschrift is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)