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The targeting of transforming growth factor β (TGF-β) has been shown to reduce complications related to ischemia-reperfusion injury (IRI) post-surgically. Pirfenidone (PFD) specifically inhibits TGF-β expression and has been demonstrated to provide protection from IRI in short-term allograft models, though not yet in long-term models. A chronic unilateral IRI model was established using male Wistar rats. The animals were divided into two groups: one with IRI and a pre-treatment of PFD (0.5 mg/kg) followed by 0.5 mg/kg/day of orally administered PFD for 30 days, and a control group without PFD treatment. A sham group was also included. Kidneys and blood samples were collected after 30 days, and the renal function was evaluated by measuring the serum creatinine and KIM-1 levels. RT-PCR was used to analyze fibrosis-related genes, and Luminex to quantify the pro-inflammatory serum IL-18 cytokine. Renal section staining and histological analysis were used to detect collagen deposits. Comparison within the groups showed an increase in serum creatinine and KIM-1 expression after IRI in the control group, while PFD reduced COLL1A1 and TGF-β expression and demonstrated a reduction in fibrosis through histological stains. The treatment group also showed a reduction in IL-18. Our results suggest that PFD exerts protective effects on chronic renal IRI, reducing fibrosis development and inflammation. This study provides new insights into the treatment and management of chronic renal function loss after IRI.

BackgroundTheMUC5Bpromoter variant (rs35705950) and telomere length are linked to pulmonary fibrosis and CT-based qualitative assessments of interstitial abnormalities, but their associations with longitudinal quantitative changes of the lung interstitium among community-dwelling adults are unknown.MethodsWe used data from participants in the Multi-Ethnic Study of Atherosclerosis with high-attenuation areas (HAAs, Examinations 1–6 (2000–2018)) andMUC5Bgenotype (n=4552) and telomere length (n=4488) assessments. HAA was defined as the per cent of imaged lung with attenuation of −600 to −250 Hounsfield units. We used linear mixed-effects models to examine associations ofMUC5Brisk allele (T) and telomere length with longitudinal changes in HAAs. Joint models were used to examine associations of longitudinal changes in HAAs with death and interstitial lung disease (ILD).ResultsTheMUC5Brisk allele (T) was associated with an absolute change in HAAs of 2.60% (95% CI 0.36% to 4.86%) per 10 years overall. This association was stronger among those with a telomere length below an age-adjusted percentile of 5% (p value for interaction=0.008). A 1% increase in HAAs per year was associated with 7% increase in mortality risk (rate ratio (RR)=1.07, 95% CI 1.02 to 1.12) for overall death and 34% increase in ILD (RR=1.34, 95% CI 1.20 to 1.50). Longer baseline telomere length was cross-sectionally associated with less HAAs from baseline scans, but not with longitudinal changes in HAAs.ConclusionsLongitudinal increases in HAAs were associated with theMUC5Brisk allele and a higher risk of death and ILD.

IntroductionPersisting respiratory symptoms in COVID-19 survivors may be related to development of pulmonary fibrosis. We assessed the proportion of chest CT scans and pulmonary function tests consistent with parenchymal lung disease in the follow-up of people hospitalised with COVID-19 and viral pneumonitis.MethodsSystematic review and random effects meta-analysis of proportions using studies of adults hospitalised with SARS-CoV-2, SARS-CoV, MERS-CoV or influenza pneumonia and followed up within 12 months. Searches performed in MEDLINE and Embase. Primary outcomes were proportion of radiological sequelae on CT scans; restrictive impairment; impaired gas transfer. Heterogeneity was explored in meta-regression.ResultsNinety-five studies (98.9% observational) were included in qualitative synthesis, 70 were suitable for meta-analysis including 60 SARS-CoV-2 studies with a median follow-up of 3 months. In SARS-CoV-2, the overall estimated proportion of inflammatory sequelae was 50% during follow-up (0.50; 95% CI 0.41 to 0.58; I2=95%), fibrotic sequelae were estimated in 29% (0.29; 95% CI 0.22 to 0.37; I2=94.1%). Follow-up time was significantly associated with estimates of inflammatory sequelae (−0.036; 95% CI −0.068 to –0.004; p=0.029), associations with fibrotic sequelae did not reach significance (−0.021; 95% CI −0.051 to 0.009; p=0.176). Impaired gas transfer was estimated at 38% of lung function tests (0.38 95% CI 0.32 to 0.44; I2=92.1%), which was greater than restrictive impairment (0.17; 95% CI 0.13 to 0.23; I2=92.5%), neither were associated with follow-up time (p=0.207; p=0.864).DiscussionSequelae consistent with parenchymal lung disease were observed following COVID-19 and other viral pneumonitis. Estimates should be interpreted with caution due to high heterogeneity, differences in study casemix and initial severity.PROSPERO registration numberCRD42020183139.

Chronic kidney disease (CKD) is a slow-developing, progressive deterioration of renal function. The final common pathway in the pathophysiology of CKD involves glomerular sclerosis, tubular atrophy and interstitial fibrosis. Transforming growth factor-beta (TGF-β) stimulates the differentiation of fibroblasts towards myofibroblasts and the production of extracellular matrix (ECM) molecules, and thereby interstitial fibrosis. It has been shown that endoglin (ENG, CD105), primarily expressed in endothelial cells and fibroblasts, can function as a co-receptor of TGF signaling. In several human organs, endoglin tends to be upregulated when chronic damage and fibrosis is present. We hypothesize that endoglin is upregulated in renal interstitial fibrosis and plays a role in the progression of CKD. We first measured renal endoglin expression in biopsy samples obtained from patients with different types of CKD, i.e., IgA nephropathy, focal segmental glomerulosclerosis (FSGS), diabetic nephropathy (DN) and patients with chronic allograft dysfunction (CAD). We showed that endoglin is upregulated in CAD patients (p < 0.001) and patients with DN (p < 0.05), compared to control kidneys. Furthermore, the amount of interstitial endoglin expression correlated with eGFR (p < 0.001) and the amount of interstitial fibrosis (p < 0.001), independent of the diagnosis of the biopsies. Finally, we investigated in vitro the effect of endoglin overexpression in TGF-β stimulated human kidney fibroblasts. Overexpression of endoglin resulted in an enhanced ACTA2, CCN2 and SERPINE1 mRNA response (p < 0.05). It also increased the mRNA and protein upregulation of the ECM components collagen type I (COL1A1) and fibronectin (FN1) (p < 0.05). Our results suggest that endoglin is an important mediator in the final common pathway of CKD and could be used as a possible new therapeutic target to counteract the progression towards end-stage renal disease (ESRD).

The Winter Meeting of the British Thoracic Society (BTS) is a platform for the latest clinical and scientific research in respiratory medicine. This review summarises the key symposia and presentations from the BTS Winter Meeting 2021 held online due to the COVID-19 pandemic.

Interstitial fibrosis and tubular atrophy (IFTA) on a renal biopsy are strong indicators of disease chronicity and prognosis. Techniques that are typically used for IFTA grading remain manual, leading to variability among pathologists. Accurate IFTA estimation using computational techniques can reduce this variability and provide quantitative assessment. Using trichrome-stained whole-slide images (WSIs) processed from human renal biopsies, we developed a deep-learning framework that captured finer pathologic structures at high resolution and overall context at the WSI level to predict IFTA grade. WSIs (n = 67) were obtained from The Ohio State University Wexner Medical Center. Five nephropathologists independently reviewed them and provided fibrosis scores that were converted to IFTA grades: ≤10% (none or minimal), 11% to 25% (mild), 26% to 50% (moderate), and >50% (severe). The model was developed by associating the WSIs with the IFTA grade determined by majority voting (reference estimate). Model performance was evaluated on WSIs (n = 28) obtained from the Kidney Precision Medicine Project. There was good agreement on the IFTA grading between the pathologists and the reference estimate (κ = 0.622 ± 0.071). The accuracy of the deep-learning model was 71.8% ± 5.3% on The Ohio State University Wexner Medical Center and 65.0% ± 4.2% on Kidney Precision Medicine Project data sets. Our approach to analyzing microscopic- and WSI-level changes in renal biopsies attempts to mimic the pathologist and provides a regional and contextual estimation of IFTA. Such methods can assist clinicopathologic diagnosis.

Rationale & Objective Existing data sets correlating kidney histopathologic findings with kidney function have low proportions of elderly patients (and those with a family history of kidney failure are over-represented), which limits their generalizability. Our objective was to use non-neoplastic tissue from nephrectomy specimens to examine the association between degree of histopathologic changes and estimated glomerular filtration rate (eGFR) and determine whether the association differed by age. Study Design Cross-sectional study. Exposures Glomerulosclerosis (GS), interstitial fibrosis/tubular atrophy (IFTA), and arterial sclerosis/arteriosclerosis (AS). Outcome eGFR. Analytical Approach We retrospectively reviewed kidney pathology reports (of non-neoplastic tissue) from 1,347 patients who underwent nephrectomy (1999-2018) for any indication but most commonly due to kidney cancer. We evaluated the association between degree of GS, IFTA, and AS with eGFR at the time of nephrectomy and whether this was modified by age. Results Among the participants (aged 17-91 years), 42% and 57.8% had >10% GS and IFTA, respectively, and 81.8% had moderate or severe AS. We found that greater degrees of GS, IFTA, and AS were associated with lower eGFR after multivariable adjustment. Although there was a greater prevalence of more severe degrees of GS and IFTA in older individuals, the association between various histopathologic features and eGFR was not modified by age. Limitations Retrospective cross-sectional study. Conclusions Our study demonstrates differences in the histologic appearance of the kidneys across levels of eGFR. Although the prevalence of advanced changes was higher in the oldest group of patients, a subset had excellent kidney function and limited histologic changes.

Background Common genetic variants of the enzymes and efflux pump involved in tacrolimus disposition have been associated with calcineurin inhibitor nephrotoxicity, but their importance is unclear because of the multifactorial background of renal fibrosis. This study explores the pro-fibrotic response of tacrolimus exposure in relation to the differential capacity for tacrolimus metabolism in proximal tubule cells (PTCs) with a variable (pharmaco)genetic background. Methods PTCs were obtained from protocol allograft biopsies with different combinations of CYP3A5 and ABCB1 variants and were incubated with tacrolimus within the concentration range found in vivo. Gene and protein expression, CYP3A5 and P-glycoprotein function, and tacrolimus metabolites were measured in PTC. Connective tissue growth factor (CTGF) expression was assessed in protocol biopsies of kidney allograft recipients. Results PTCs produce CTGF in response to escalating tacrolimus exposure, which is approximately 2-fold higher in cells with the CYP3A5*1 and ABCB1 TT combination in vitro. Increasing tacrolimus exposure results in relative higher generation of the main tacrolimus metabolite {13-O-desmethyl tacrolimus [M1]} in cells with this same genetic background. Protocol biopsies show a larger increase in in vivo CTGF tissue expression over time in TT vs. CC/CT but was not affected by the CYP3A5 genotype. Conclusions Tacrolimus exposure induces a pro-fibrotic response in a PTC model in function of the donor pharmacogenetic background associated with tacrolimus metabolism. This finding provides a mechanistic insight into the nephrotoxicity associated with tacrolimus treatment and offers opportunities for a tailored immunosuppressive treatment.

ObjectivesIdiopathic pulmonary fibrosis (IPF) primarily affects the aged population and is characterised by failure of alveolar regeneration, leading to loss of alveolar type 1 (AT1) cells. Aged mouse models of lung repair have demonstrated that regeneration fails with increased age. Mouse and rat lung repair models have shown retinoic acid (RA) treatment can restore alveolar regeneration. Herein, we seek to determine the signalling mechanisms that become activated on RA treatment prior to injury, which support alveolar differentiation.DesignPartial pneumonectomy lung injury model and next-generation sequencing of sorted cell populations were used to uncover molecular targets regulating alveolar repair. In vitro organoids generated from epithelial cells of mouse or patient with IPF co-cultured with young, aged or RA-pretreated murine fibroblasts were used to test potential targets.Main outcome measurementsKnown alveolar epithelial cell differentiation markers, including HOPX and AGER for AT1 cells, were used to assess outcome of treatments.ResultsGene expression analysis of sorted fibroblasts and epithelial cells isolated from lungs of young, aged and RA-pretreated aged mice predicted increased platelet-derived growth factor subunit A (PDGFA) signalling that coincided with regeneration and alveolar epithelial differentiation. Addition of PDGFA induced AT1 and AT2 differentiation in both mouse and human IPF lung organoids generated with aged fibroblasts, and PDGFA monoclonal antibody blocked AT1 cell differentiation in organoids generated with young murine fibroblasts.ConclusionsOur data support the concept that RA indirectly induces reciprocal PDGFA signalling, which activates regenerative fibroblasts that support alveolar epithelial cell differentiation and repair, providing a potential therapeutic strategy to influence the pathogenesis of IPF.

Ground-glass opacities (GGO) are frequently found in interstitial lung diseases (ILD) and may represent either active inflammation or subresolution interstitial fibrosis. We sought to investigate the ability of lung MRI to predict treatment response in individuals with ILD presenting with predominant GGO.SSFSE/PROPELLER T2 match/mismatch was able to discriminate responders from nonresponders for the primary endpoint in 12 of 15 participants (80% accuracy,SSFSE-PROPELLER T2 match/mismatch was predictive of treatment response status in this group of ILD patients.

Tenascin-C is a marker of interstitial fibrosis. We assessed whether plasma Tenascin-C differed between heart failure with preserved ejection fraction (HFpEF) and asymptomatic controls and related to clinical outcomes. Prospective, observational study of 172 age- and sex-matched subjects (HFpEF n = 130; controls n = 42, age 73 ± 9, males 50%) who underwent phenotyping with 20 plasma biomarkers, echocardiography, cardiac MRI and 6-minute-walk-testing. The primary endpoint was the composite of all-cause death/HF hospitalisation. Tenascin-C was higher in HFpEF compared to controls (13.7 [10.8–17.3] vs (11.1 [8.9–12.9] ng/ml, p p During follow-up (median 1428 days), there were 61 composite events (21 deaths, 40 HF hospitalizations). In multivariable Cox regression analysis, Tenascin-C (adjusted hazard ratio [HR] 1.755, 95% confidence interval [CI] 1.305–2.360; p p = 0.039) were independently associated with adverse outcomes. In HFpEF, plasma Tenascin-C is higher compared to age- and sex-matched controls and a strong predictor of adverse outcomes. Trial registration: ClinicalTrials.gov: NCT03050593

In the 2013 updated classification of the American Thoracic Society/European Respiratory Society, airway-centered interstitial fibrosis (ACIF) is included as a bronchiolocentric pattern of interstitial pneumonia (IP) among idiopathic IPs. We encountered a case of severe pulmonary hypertension (PH) with chronic IP. The patient initially presented with shortness of breath and often lost consciousness due to PH, and seven years after his first visit, he ultimately died. An autopsy revealed ACIF and usual IP. In particular, the ACIF comprised non-atypical smooth muscle hyperplasia, and pulmonary hypertensive vascular degeneration was detected. This case may represent a new pathological feature of ACIF.

IntroductionIdiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease of unknown aetiology and cure. Recent studies have reported a dysregulation of exosomal microRNAs (miRs) in the IPF context. However, the impact of IPF-related exosomal miRs on the progression of pulmonary fibrosis is unknown.MethodsTwo independent cohorts were enrolled at the ambulatory care polyclinic of Liège University. Exosomes from sputum were obtained from 19 patients with IPF and 23 healthy subjects (HSs) (cohort 1), and the ones from plasma derived from 14 patients with IPF and 14 HSs (cohort 2). Exosomal miR expression was performed by quantitative reverse transcription–PCR. The functional role of exosomal miRs was assessed in vitro by transfecting miR mimics in human alveolar epithelial cells and lung fibroblasts.ResultsExosomal miR analysis showed that miR-142-3p was significantly upregulated in sputum and plasma of patients with IPF (8.06-fold, pDiscussionOur results suggest that macrophage-derived exosomes may fight against pulmonary fibrosis progression via the delivery of antifibrotic miR-142–3 p to alveolar epithelial cells and lung fibroblasts.

Main problem Luminex panel and single antigen beads (SAB) are used for screening and DSA specificity determination respectively. The cost of SAB may limit its general use, so some labs perform SAB tests only after positive screening. Methods We compared both strategies: 1) SAB only if positive screening with kits from manufacturer A, and 2) direct SAB from manufacturer B, and correlate their sensitivity with histological findings. Results We selected 118 kidney transplant recipients with a normal biopsy (n = 19), histological antibody-mediated damage (ABMR, n = 52) or interstitial fibrosis/tubular atrophy (IFTA, n = 47) following Banff 2015 and 2017 classification. Direct SAB detected DSA in 13 patients missed by screening. Strategy 1 detected DSA in 0% normal, 61.5% ABMR and 8.5% IFTA patients; percentages with strategy 2 were 5.2%, 78.8% and 14.8% (p=0.004). Strategy 2 identified DSA allowing full ABMR diagnosis in 17% cases missed by strategy 1. Thereafter, direct SAB from manufacturer A confirmed DSA in 46% DSA-positive cases with strategy 2 (55.5% ABMR cases). Conclusions Luminex screening failed to identify clinically relevant HLA antibodies, hampering DSA detection in patients with possible ABMR. Direct SAB testing should be the chosen strategy for post-transplantation monitoring, albeit direct SAB from the two existing manufacturers may diverge in as much as 50% of cases.

Previous reports suggest initial presentation of IgA nephropathy (IgAN) in children is different from adults. No systematic comparison of clinical, biological, and histological childhood- and adult-onset IgAN is currently available. We compared pediatric and adult clinical and histological characteristics at IgAN diagnosis. Data on 211 consecutive patients from two different centers in Paris (82 children, 129 adults) were reviewed. Kidney biopsies were scored for Oxford classification and podocytopathic (P1) features. We report higher eGFR at diagnosis in children compared to adults (89.5 vs. 64 ml/min/1.73 m2; p = 0.0001) but no difference in proteinuria. Histological analysis of kidney biopsy found higher proportions of mesangial (M1) and endocapillary (E1) hypercellularity in children compared with adults (M1 [80.7% vs. 27.9%, p = 0.0001]; E1 [71.3% vs. 30%, p = 0.0001]). Focal glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis ≥ 25% (T1), and P1 were more frequent in adults (S1 [81.5% vs. 61.3%, p = 0.0012], T1 [49.5% vs. 1.35%, p = 0.0001], P1 [33.8% vs. 16.4%, p = 0.008). Proteinuria associated with M1, E1, and C1 in children (M1, p = 0.0001; E1, p = 0.0005; C1, p = 0.0014) but S1, P1, and T1 in adults (S1, p = 0.0001; P1, p = 0.0001; T1, p = 0.001). After steroid treatment (41 children and 28 adults), proteinuria decreased in children (p < 0.001, follow-up 38 months) and adults (p < 0.001, follow-up 76.9 months), whereas eGFR remained stable in adults but increased significantly in children (90.6 to 110 ml/min/1.73m2). Proteinuria in children with IgAN is a marker of glomerular proliferative lesions whereas its presence in adults often reflects the presence of chronic lesions. This suggests the need for histological assessment.

Radiation therapy (RT) is a common adjunct therapy in oncology. However, it carries a significant risk of lymphedema when utilized in some anatomic locations. Recent studies have provided insight into lymphedema pathophysiology, diagnostic techniques, and RT. This review will examine the role of RT in upper and lower extremity lymphedema. Radiation’s role in increasing the risk of lymphedema through decreased lymphatic proliferation potential, interstitial fibrosis compressing lymphatic vessels, and mechanical insufficiency of the lymphatic system will be reviewed.

Introduction:This study evaluated the initial use of label-free second harmonic generation (SHG) imaging with two-photon excitation (2PE) auto-fluorescence for the quantification of collagen/fibrosis on pre-implantation biopsies of extended criteria donors (ECD).Methods:A total of 20 core ECD kidney transplant biopsy specimen tissues from 7 ECD donors, taken at the time of pre-implantation were retrieved, cut into 5-micron sections, mounted on slides and deparaffinized. The core needle biopsies were imaged with 2X and 20X objective using the commercially available laser-based Genesis® 200 (Histoindex Pte Ltd and Clinnovate Pte Ltd, Singapore). The entire core was selected as the Region of Interest (ROI). Corresponding clinical information from transplant donors were retrieved. Histopathological review was performed, and all biopsies had Interstitial Fibrosis (IF)/Tubular Atrophy (TA) scores > 0. Collagen parameters measured included quantification by the Collagen Area Ratio in Tissue (CART) and qualitative measurements by Collagen Reticulation Index (CRI).Results: 20 explant core biopsies were extracted from 10 donor kidney samples, of which originated from 7 donors. Table 1 depicts the baseline ECD characteristics of the donors. For the kidneys with multiple biopsies done, we obtained an average score of the collagen parameters across the different samples. Biopsies classified with > 85% KDPI score had significantly higher CAR and CART than biopsies with ≤ 85% KDPI score.Conclusion:MPM is an evolving technology that enables the quantification of the amount (CART) and quality (CRI) of collagen deposition in unstained explant biopsies of ECD kidneys. This initial evaluation found significant differences in both parameters between ECD kidneys with more or less than 85% KDPI scores.

Background: IgA nephropathy (IgAN) is a major cause of chronic glomerulonephritis worldwide. T cell dysregulation has been reported to contribute to the pathogenesis of IgAN. Methods We measured a broad range of Th1, Th2 and Th17 cytokines in the serum of IgAN patients. We searched for significant cytokines, which were associated with clinical parameters and histological scores in IgAN patients. Results: Among 15 cytokines, the levels of soluble CD40L (sCD40L) and IL-31 were higher in IgAN patients and were significantly associated with a higher estimated glomerular filtration rate (eGFR), a lower urinary protein to creatinine ratio (UPCR), and milder tubulointerstitial lesions (i.e., the early phase of IgAN). Multivariate analysis revealed that serum sCD40L was an independent determinant of a lower UPCR after adjustment for age, eGFR, and mean blood pressure (MBP). CD40, a receptor of sCD40L, has been reported to be upregulated on mesangial cells in IgAN. The sCD40L/CD40 interaction may directly induce inflammation in mesangial areas and may therefore be involved in the development of IgAN. Conclusions: The present study demonstrated the significance of serum sCD40L and IL-31 in the early phase of IgAN. Serum sCD40L may be a marker of the beginning of inflammation in IgAN.

Despite improvements in patient survival and quality of life, long-term renal survival has not changed significantly in the recent decades and nephritis relapses affect over 50% of patients with lupus nephritis. Renal fibrosis affecting the tubulointerstitial compartment is a central determinant of the prognosis of any kidney disease. Notwithstanding this evidence, the current 2003 ISN/RPS classification still focuses on glomerular pathology and does not include a mandatory score with clear subcategories of the tubulointerstitial injury in the biopsy. The pathogenesis, and the morphological and molecular characteristics of this process in patients with lupus nephritis will be considered, together with a discussion about the concepts the clinician needs to efficiently address in this injury during daily practice and in future clinical trials. Both tubulointerstitial inflammation and fibrosis are strongly correlated with poor renal outcomes in lupus nephritis, regardless of the extent of glomerular damage. Therefore, it is essential to develop reliable and noninvasive approaches to predict which patients are most likely to develop CKD so that appropriate interventions can be adopted before ESRD is established. Currently, no ideal method for monitoring kidney fibrosis exists, since repeated renal biopsies are invasive. Promising methods for assessing and monitoring fibrosis non-invasively include imaging techniques, such as magnetic resonance imaging or ex vivo confocal microscopy, integrated in computational and digital pathology techniques. Finally, beyond specific immunosuppressive treatment in Lupus Nephritis, identifying and treating cardiovascular risk factors should be a cornerstone of treatment in these patients. RESUMEN A pesar de las mejoras en la sobrevida de los pacientes y su calidad de vida, la sobrevida renal en el largo plazo no ha cambiado significativamente durante las últimas décadas, y las recidivas nefríticas afectan a más del 50% de los pacientes con nefritis lúpica. La fibrosis renal, que afecta el compartimiento tubulointersticial, es un factor determinante central en el pronóstico de todas las patologías renales. A pesar de la evidencia, la actual clasificación ISN/RPS del 2003 todavía se concentra en la patología glomerular y no incluye un score obligatorio con claras subcategorías de la lesión tubulointersticial en la biopsia. Se hablará de la patogenia y las características morfológicas y moleculares de este proceso en pacientes con nefritis lúpica, así como de los conceptos que el clínico necesita para abordar esta lesión de manera eficiente en su práctica cotidiana y en los estudios clínicos a futuro. Tanto la inflamación tubulointersticial como la fibrosis se relacionan fuertemente con desenlaces renales pobres en la nefritis lúpica, con independencia de la extensión del dañío glomerular. Resulta por lo tanto esencial desarrollar sistemas confiables y no invasivos para predecir cuáles pacientes tendrán mayor probabilidad de desarrollar enfermedad renal crónica, a fin de realizar las intervenciones apropiadas antes de que se establezca la enfermedad renal terminal (ERT). En la actualidad, no existe un método ideal para monitorear la fibrosis renal, dado que las biopsias repetidas son procedimientos invasivos. Algunos de los métodos promisorios para evaluar y monitorear la fibrosis de manera no invasiva son las técnicas de imágenes, tales como la resonancia magnética o la microscopía confocal ex vivo, integradas en técnicas de patología computarizadas y digitales. Finalmente, más allá del tratamiento inmunosupresor específico para la nefritis lúpica, identificar y tratar los factores de riesgo cardiovascular deberá ser uno de los pilares de tratamiento en estos pacientes.

Klotho is an antiaging protein reported to suppress transforming growth factor-β1 (TGF-β1) signaling. Aging kidneys are characterized by interstitial fibrosis, accumulation of cell cycle-arrested cells, and increased levels of oxidative stress. TGF-β1 signaling is involved in these processes. In this study, we investigated whether klotho overexpression improves these features in the kidneys of aging mice and examined the inhibitory effect of klotho on signaling molecules related to transforming growth of TGF-β1. Klotho transgenic (KLTG) and wild-type (WT) mice were used, and 8-wk-old and 24-mo-old mice were defined as young and aging, respectively. We found that klotho expression was decreased in aging WT mice, but it was maintained in aging KLTG mice. Klotho overexpression improved the survival of 24-mo-old mice. Although the serum Ca

Background: Galectin-3 (Gal-3) is a multifunctional glycan-binding protein shown to be linked to chronic inflammation and fibrogenesis. Plasma Gal-3 is associated with proteinuria and renal dysfunction, but its role has never been confirmed with kidney biopsy results. In our study, we aimed to explore the expression of Gal-3 in biopsy-proven patients, and we tested the hypothesis that chronic kidney disease (CKD) leads to upregulation of plasma Gal-3 expression in corresponding biopsy findings and RNA sequencing analysis.Method: In 249 patients (male/female: 155/94, age: 57.2 ± 16.3 years) who underwent kidney biopsy, plasma levels of Gal-3 were measured to estimate the association of renal fibrosis. Relationships between plasma Gal-3 levels, estimated glomerular filtration rate (eGFR) and renal histology findings were also assessed. We further examined the gene expression of Gal-3 in RNA-sequencing analysis in biopsy-proven patients.Results: Compared to patients without CKD, CKD patients had higher levels of plasma Gal-3 (1,016.3 ± 628.1 pg/mL vs. 811.6 ± 369.6 pg/ml; P = 0.010). Plasma Gal-3 was inversely correlated with eGFR (P = 0.005) but not with proteinuria. Higher Gal-3 levels were associated with interstitial fibrosis, tubular atrophy and vascular intimal fibrosis. RNA-sequencing analysis showed the upregulation of Gal-3 in fibrotic kidney biopsy samples, and the differentially expressed genes were mainly enhanced in immune cell activation and the regulation of cell-cell adhesion.Conclusions: Plasma Gal-3 levels are inverse correlated with eGFR but positively correlated with renal fibrosis, which may be involved in the immune response and associated pathways. These findings support the role of Gal-3 as a predictive marker of renal fibrosis.

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a group of chronic relapsing inflammatory conditions. Although IgG4-RD can occur in various organs, it is rarely observed in mammary glands. Here, we report a case of IgG4-related mastitis (IgG4-RM) that needed to be differentiated from breast cancer. A 54-year-old woman was examined for a tumor in her left breast. Mammary ultrasonography revealed an irregular hypoechoic tumor measuring 45.0 × 43.0 × 32.0 mm in size. A core-needle biopsy of the left breast tissue revealed a high degree of mixed T and B lymphocytic and plasma cell infiltration, as well as interstitial fibrosis. IgG4-RD was diagnosed based on hematological examination that revealed an abnormal IgG4 value of 332 mg/dl. All the clinical diagnostic criteria for IgG4 were met, resulting in a definitive diagnosis of IgG4-RM.

IntroductionRecent discoveries have identified shortened telomeres and related mutations in people with pulmonary fibrosis (PF). There is evidence to suggest that androgens, including danazol, may be effective in lengthening telomeres in peripheral blood cells. This study aims to assess the safety and efficacy of danazol in adults and children with PF associated with telomere shortening.Methods and analysisA multi-centre, double-blind, placebo-controlled, randomised trial of danazol will be conducted in subjects aged >5 years with PF associated with age-adjusted telomere length ≤10th centile measured by flow fluorescence in situ hybridisation; or in children, a diagnosis of dyskeratosis congenita. Adult participants will receive danazol 800 mg daily in two divided doses or identical placebo capsules orally for 12 months, in addition to standard of care (including pirfenidone or nintedanib). Paediatric participants will receive danazol 2 mg/kg/day orally in two divided doses or identical placebo for 6 months. If no side effects are encountered, the dose will be escalated to 4 mg/kg/day (maximum 800 mg daily) orally in two divided doses for a further 6 months. The primary outcome is change in absolute telomere length in base pairs, measured using the telomere shortest length assay (TeSLA), at 12 months in the intention to treat population.Ethics and disseminationEthics approval has been granted in Australia by the Metro South Human Research Ethics Committee (HREC/2020/QMS/66385). The study will be conducted and reported according to Standard Protocol Items: Recommendations for Interventional Trials guidelines. Results will be published in peer-reviewed journals and presented at international and national conferences.Trial registration numbersNCT04638517; Australian New Zealand Clinical Trials Registry (ACTRN12620001363976p).

BACKGROUND AND OBJECTIVES We aimed to determine outcomes with transplanting kidneys from deceased donors with severe acute kidney injury requiring acute renal replacement therapy (RRT). MATERIALS AND METHODS A total of 172 recipients received a kidney from donors with acute kidney injury stage 3 (AKIN3) requiring RRT. We compared the study group to 528 recipients who received a kidney from donors with AKIN stage 3 not on RRT and 463 recipients who received

BackgroundThe Banff classification standardizes the diagnoses of kidney transplant rejection based on histological criteria. Clinical decisions are generally made after integration of the Banff diagnoses in the clinical context. However, interpretation of the biopsy cases is still heterogeneous among pathologists or clinicians. Machine Learning (ML) algorithms may be trained from expertly assessed cases to provide clinical decision support.MethodsThe ML technique of Extreme Gradient Boosting learned from two large training datasets from the European programs BIOMARGIN and ROCKET (n= 631 and 304), in which biopsies were read centrally and consensually interpreted by a group of experts and used as a reference for untargeted biomarker screenings. The model was then externally validated in three independent datasets (n= 3744, 589 and 360).ResultsIn the three validation datasets, the algorithm yielded a ROC curve AUC of mean (95% CI) 0.97 (0.92-1.00), 0.97 (0.96-0.97) and 0.95 (0.93-0.97) for antibody-mediated rejection (ABMR); 0.94 (0.91-0.96), 0.94 (0.92-0.95) and 0.91 (0.88-0.95) for T cell-mediated rejection; >0.96 (0.90-1.00) in all three for interstitial fibrosis - tubular atrophy (IFTA). Finally, using the largest validation cohort, we developed an additional algorithm to discriminate active and chronic active ABMR with an accuracy of 0.95.ConclusionWe built an Artificial Intelligence algorithm able to interpret histological lesions together with a few routine clinical data with very high sensitivity and specificity. This algorithm should be useful in routine or clinical trials to help pathologists and clinicians and increase biopsy interpretation homogeneity.

Background Mesenchymal stem cells (MSCs)-based therapy has shown promising results for renal injury. In this study, the efficacy and safety of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in treating nonspecific interstitial fibrosis and tubular atrophy (IFTA) were evaluated. Methods From March 2011 to January 2013, 11 renal transplanted patients with IFTA were recruited. At baseline, patients were given one intra-arterial infusion of BM-MSCs; 7 days and 1 month later, another two intravenous infusions of cells were followed. Serum creatinine, creatinine clearance rate, and serum cystatin-C at baseline and 7 days, 1 month, 3 months, 6 months, and 12 months after the intra-arterial infusion of BM-MSCs were used to assess renal function. At baseline and 6 months, histological examination based on hematoxylin-eosin, Masson’s trichrome and periodic acid-Schiff staining and immunohistochemistry for transforming growth factor β1 (TGF-β1) and connective tissue growth factor (CTGF) was performed. Adverse events were recorded to evaluate the safety of BM-MSCs treatment. Results At 12 months, the renal function of 6 patients (54.5%) was improved, 3 (27.3%) were stable and 2 (18.2%) were worsened. At 6 months, the mean IFTA scores of all participators were similar with the baseline (1.73 ± 0.41 vs.1.50 ± 0.0.77, p = 0.242); however, it was significantly decreased when only 6 patients with improved renal function were analyzed (1.67 ± 0.41 vs. 1.08 ± 0.20, p = 0.013). Besides, decreased expression of TGF-β1 and CTGF were also observed at 6 months. During 1 year follow-up period, only two minor complications including infection and allergy were observed. Conclusion Our results demonstrated that autologous BM-MSCs are safe and beneficial for IFTA patients. Abbreviations: MSCs: mesenchymal stem cells; BM-MSCs: marrow-derived mesenchymal stem cells; IFTA: interstitial fibrosis and tubular atrophy; CAN: chronic allograft nephropathy; CNIs: calcineurin inhibitors; Scr: serum creatinine; CCr: creatinine clearance rate; Cys-C: cystatin-C; TGF-β1: transforming growth factor β1; CTGF: connective tissue growth factor

This case report discusses a 76-year-old man who presented with symptomatic diffuse alveolar-septal and tracheobronchial amyloidosis with a low-grade monoclonal gammopathy. This patient had a combination of both symptomatic diffuse alveolar-septal interstitial disease and tracheobronchial amyloidosis, features that contradict the widely accepted presentations seen in this disease. First, tracheobronchial amyloidosis has been documented as localised disease without systemic involvement. Second, diffuse alveolar-septal interstitial disease is rarely identified with clinical symptoms unless there is significant cardiac involvement. This case highlights a number learning points in the diagnosis and management of systemic amyloid light chain amyloidosis;(1) There is a need for a high index of suspicion for diagnosis due to the potential subtlety of a plasma cell clone underlying AL amyloidosis, requiring serum-free light chain assays to increase sensitivity; (2) Haematological response and recovery of organ dysfunction are not a linear relationship due to the slower reversal of amyloid deposition; therefore, ongoing monitoring is required to identify those in need of repeated therapy. However, haematological response is a marker of overall survival and (3) Multisystem assessment and multidisciplinary collaboration are critical in optimising the care of patients with systemic AL amyloidosis.

Some preceding studies have provided evidence that hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) inhibitors have therapeutic potential against tubular interstitial fibrosis (TIF). Recently, transformation of renal interstitial fibroblasts (RIFs) into α-smooth muscle actin-positive myofibroblasts with loss of their hypoxia-inducible erythropoietin (EPO) expression has been hypothesized as the central mechanism responsible for TIF with renal anemia (the RIF hypothesis). These reports have suggested that HIF-PH inhibitors may suppress TIF via suppressing transformation of RIFs. However, the direct effect of HIF-PH inhibitors on transformation of RIFs has not been demonstrated because there has been no appropriate assay system. Here, we established a novel in vitro model of the transformation of RIFs. This model expresses key phenotypic changes such as transformation of RIFs accompanied by loss of their hypoxia-inducible EPO expression, as proposed by the RIF hypothesis. Using this model, we demonstrated that JTZ-951, a newly developed HIF-PH inhibitor, stabilized HIF protein in RIFs, suppressed transformation of RIFs, and maintained their hypoxia-inducible EPO expression. JTZ-951 also suppressed the expression of FGF2, FGF7, and FGF18, which are upregulated during transformation of RIFs. Furthermore, expression of Fgf2, Fgf7, and Fgf18 was correlated with TIF in an animal model of TIF. We also demonstrated that not only FGF2, which is a well-known growth-promoting factor, but also FGF18 promoted proliferation of RIFs. These data suggest that JTZ-951 has therapeutic potential against TIF with renal anemia. Furthermore, FGF2, FGF7, and FGF18, which faithfully reflect the anti-TIF effects of JTZ-951, have potential as TIF biomarkers.

Objectives This study sought to determine new reference cutoffs for normal unipolar voltage (UV) and bipolar voltage (BV) that would be adjusted for the LV remodeling. Background The definition of “normal” left ventricular (LV) endocardial voltage in patients with post-infarct scar is still lacking. The reference voltage of the noninfarcted myocardium (NIM) may differ between patients depending on LV structural remodeling and the ensuing interstitial fibrosis. Methods Electroanatomic voltage mapping was integrated with isotropic late gadolinium–enhanced cardiac magnetic resonance in 15 patients with nonremodeled LV and 12 patients with remodeled LV (end-systolic volume index >50 ml/m2 with ejection fraction Results The cutoffs for normal BV and UV were ≥3.0 and ≥6.7 mV for nonremodeled LV and ≥2.1 and ≥6.4 mV for remodeled LV. Endocardial low-voltage area (LVA) defined by the adjusted cutoffs corresponded better to late gadolinium enhancement–detected scar than did LVA defined by uniform cutoffs. In 15 patients who underwent successful ablation of ventricular tachycardia, the LVA contained >97% of targeted evoked delayed potentials. Insights from whole-heart T1 mapping revealed more fibrotic NIM in patients with remodeled LV compared with nonremodeled LV. Conclusions This study found substantial differences in endocardial voltage of NIM in post-infarct patients with remodeled versus nonremodeled LV. The new adjusted cutoffs for “normal” BV and UV enable a patient-tailored approach to electroanatomic voltage mapping of LV.

Myocardial relaxation and stiffness are influenced by fibrillar collagen content. Cyclic nucleotide signaling regulators have been investigated targeting more effective modulation of collagen deposition during myocardial healing process. To assess the effects of phosphodiesterase type 3 and phosphodiesterase type 5 inhibitors on cardiac function and left ventricular myocardial fibrosis in catecholamine-induced myocardial injury, sildenafil and pimobendan were administered to male Wistar rats 24 hours after isoproterenol injection. Echocardiography and electrocardiogram were performed to assess kinetic and rhythm changes during 45 days of drug administration. At the end of study, type I and type III collagen were measured through immunohistochemistry analysis, and left ventricular pressure was assessed through invasive method. Echocardiography assessment showed increased relative wall thickness at 45 days in pimobendan group with significant diastolic dysfunction and increased collagen I deposition compared with nontreated positive group (3.03 ± 0.31 vs. 2.73 ± 0.28%, P0.05). Diastolic pressure correlated positively with type I collagen (r = 0.54, P0.05). Type III collagen analysis did not demonstrate difference among the groups. Sildenafil administration attenuated type I collagen deposition (2.15 ± 0.51 vs. positive group, P0.05) and suggested to be related to arrhythmic events. Arrhythmic events were not related to the quantity of fibrillar collagen deposition. Although negative modulation of collagen synthesis through cyclic nucleotides signaling have shown promising results, in this study, pimobendan postconditioning resulted in increased collagen type I formation and severe diastolic dysfunction while sildenafil postconditioning reduced collagen type I deposition and attenuated diastolic dysfunction.

RationaleIdiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with poor prognosis. Identifying patients early may allow intervention which could limit progression. The ‘indeterminate for UIP’ (iUIP) CT pattern, defined in the 2018 IPF guidelines, could be a precursor to IPF but there is limited data on how patients with iUIP progress over time.ObjectiveTo evaluate the radiological progression of iUIP and explore factors linked to progression to IPF.MethodsWe performed a retrospective analysis of a lung fibrosis clinic cohort (n=230) seen between 2013-2017. Cases with iUIP were identified; first ever CTs for each patient found and categorised as ‘non-progressor’ or ‘progressors’ (the latter defined as increase in extent of disease or to ‘definite’ or ‘probable’ UIP CT pattern) during their follow up. Lung function trends, haematological data and patient demographics were examined to explore disease evolution and potential contribution to progression.Results48 cases with iUIP CT pattern were identified. Of these, 32 had follow up CT scans, of which 23 demonstrated progression. 17 patients in this cohort were diagnosed with IPF over a mean (S.D.) period of 3.9 (±1.9) years. Monocyte [HR 23, CI 1.6-340, p=0.03] and neutrophil levels [HR 1.8, CI 1.3-2.3, pConclusion53% of our evaluable iUIP patients progressed to IPF over a mean of four years. Monocyte and neutrophil levels at initial CT were significantly associated with progression in disease. These data provide a single-centre analysis of the evolution of patients with iUIP CT pattern, and first signal for potential factors associated with progression to IPF.Key messageWhat is the key question?How does the ‘indeterminate for UIP’ (iUIP) interstitial CT pattern evolve over time and what factors are associated with progression to definite and probable UIP pattern.What is the bottom line?In this retrospective single centre analysis, 53% of evaluable cases with iUIP on initial CT scan progressed to probable or definite UIP CT pattern over an average of 4 years. Monocyte and neutrophil levels performed around the time of initial CT were significantly associated with progression to definite and probable UIP pattern.Why read on?We discuss the implications of these findings, its strengths and limitations.

Histologic examination of interstitial fibrosis and tubular atrophy (IFTA) is critical to determine the extent of irreversible kidney injury in renal disease. The current clinical standard involves pathologist's visual assessment of IFTA, which is prone to inter-observer variability. To address this diagnostic variability, we designed two case studies (CSs), including seven pathologists, using HistomicsTK- a distributed system developed by Kitware Inc. (Clifton Park, NY). Twenty-five whole slide images (WSIs) were classified into a training set of 21 and a validation set of four. The training set was composed of seven unique subsets, each provided to an individual pathologist along with four common WSIs from the validation set. In CS 1, all pathologists individually annotated IFTA in their respective slides. These annotations were then used to train a deep learning algorithm to computationally segment IFTA. In CS 2, manual and computational annotations from CS 1 were first reviewed by the annotators to improve concordance of IFTA annotation. Both the manual and computational annotation processes were then repeated as in CS1. The inter-observer concordance in the validation set was measured by Krippendorff's alpha (KA). The KA for the seven pathologists in CS1 was 0.62 with CI [0.57, 0.67], and after reviewing each other's annotations in CS2, 0.66 with CI [0.60, 0.72]. The respective CS1 and CS2 KA were 0.58 with CI [0.52, 0.64] and 0.63 with CI [0.56, 0.69] when including the deep learner as an eighth annotator. These results suggest that our designed annotation framework refines agreement of spatial annotation of IFTA and demonstrates a human-AI approach to significantly improve the development of computational models.

The factors determining disease course and survival in fibrotic hypersensitivity pneumonitis (fHP) have not been fully elucidated.The aim of this study was to describe the characteristics of patients with fHP in a real-world cohort and investigate factors associated with worse outcomes. We aimed to explore the use of neutrophil to lymphocyte ratio (NLR) and peripheral blood monocyte levels in predicting mortality.MethodsA retrospective, multicentre, observational UK cohort study.ResultsPatients with fHP were significantly younger than those with idiopathic pulmonary fibrosis (IPF) (median age fHP 73 vs IPF 75 years) and were much more likely to be woman (fHP 61% vs IPF 26%). In almost half of all fHP cases (49%, n=104/211), no causative antigen was identified from either the history or specific antigen testing. Overall, fHP was associated with a better survival than IPF, although median survival of both groups was poor (fHP 62 months vs IPF 52 months).IPF survival in patients with a high NLR was significantly lower than those with a low NLR (44 vs 83 months). A monocyte count ≥0.95 K/uL also predicted significantly poorer outcomes for patients with IPF compared with ConclusionsAlthough fHP has a statistically lower mortality than IPF, absolute survival time of both conditions is poor. High baseline NLR and absolute monocyte counts predict worse survival in IPF but not in fHP, highlighting the potential for divergence in their pathogenic mechanisms.

Background Tubulointerstitial fibrosis (TIF) is one of the main pathological features of various progressive renal damages and chronic kidney diseases. Mesenchymal stromal cells (MSCs) have been verified with significant improvement in the therapy of fibrosis diseases, but the mechanism is still unclear. We attempted to explore the new mechanism and therapeutic target of MSCs against renal fibrosis based on renal proteomics. Methods TIF model was induced by adenine gavage. Bone marrow-derived MSCs was injected by tail vein after modeling. Renal function and fibrosis related parameters were assessed by Masson, Sirius red, immunohistochemistry, and western blot. Renal proteomics was analyzed using iTRAQ-based mass spectrometry. Further possible mechanism was explored by transfected galectin-3 gene for knockdown (Gal-3 KD) and overexpression (Gal-3 OE) in HK-2 cells with lentiviral vector. Results MSCs treatment clearly decreased the expression of α-SMA, collagen type I, II, III, TGF-β1, Kim-1, p-Smad2/3, IL-6, IL-1β, and TNFα compared with model rats, while p38 MAPK increased. Proteomics showed that only 40 proteins exhibited significant differences (30 upregulated, 10 downregulated) compared MSCs group with the model group. Galectin-3 was downregulated significantly in renal tissues and TGF-β1-induced rat tubular epithelial cells and interstitial fibroblasts, consistent with the iTRAQ results. Gal-3 KD notably inhibited the expression of p-Akt, p-GSK3β and snail in TGF-β1-induced HK-2 cells fibrosis. On the contrary, Gal-3 OE obviously increased the expression of p-Akt, p-GSK3β and snail. Conclusion The mechanism of MSCs anti-renal fibrosis was probably mediated by galectin-3/Akt/GSK3β/Snail signaling pathway. Galectin-3 may be a valuable target for treating renal fibrosis.

We recently identified epigallocatechin gallate (EGCG), a trihydroxyphenolic compound, as a dual inhibitor of lysyl oxidase-like2 and transforming growth factor-β1 (TGFβ1) receptor kinase that when given orally to patients with idiopathic pulmonary fibrosis (IPF) reversed profibrotic biomarkers in their diagnostic biopsies. Here, we extend these findings to advanced pulmonary fibrosis using cultured precision-cut lung slices from explants of patients with IPF undergoing transplantation. During these experiments, we were surprised to discover that not only did EGCG attenuate TGFβ1 signalling and new collagen accumulation but also activated matrix metalloproteinase-dependent collagen I turnover, raising the possibility of slow fibrosis resolution with continued treatment.

Introduction: Renal cell carcinoma may extend into the inferior vena cava (IVC) by the tumour thrombus (TT). Renal cell carcinoma with tumour thrombus (RCC/TT) could be associated with multiple collaterals making the surgery in cases of venous involvement very complex and challenging. The pathologic findings of non-neoplastic parenchymal changes in radical nephrectomy specimens of RCC/TT have not been well described. Methods: We conducted a retrospective study of 200 nephrectomies for RCC/TT during eight years. We only included 22 patients who had a full histopathological examination of the resected nephrectomies, including the non-neoplastic parenchymal tissues. Results: Median tumour thrombus level was III (range: II-IV), and median tumour diameter was 9.3 (range: 4-17) cm. Clear cell RCC was the most common tumour diagnosis in this cohort. Non-neoplastic renal pathologies included: (1) Global Glomerulosclerosis (GGS) in 90.9% (1-9% GGS in 15, 10-30% GGS in 4, >30% GGS in 1); (2) Interstitial fibrosis in 90.9% (mild in nine, moderate in nine, severe in 2); (3) Acute tubular injury in 14 (63.6%) patients; (4) Chronic inflammation in 77.3% (5-25% in 10, 26-50% in 7); (5) Arteriolosclerosis in all patients (mild, moderate and severe in 12, 9 and 1 patients, respectively); (6) Arteriolosclerosis: as none in 12, mild in six, moderate in four patients; (7) Focal Segmental Glomerulosclerosis in one patient. Our findings suggest that non-neoplastic parenchymal changes occur in the presence of RCC/TT. Neither tumour extension (via T-stage) nor tumour thrombus level were associated with the degree of any of these non-neoplastic parenchymal changes. Conclusions: Knowledge of the existence of these non-neoplastic parenchymal changes in addition to determining the tumour margin(s) will be important in caring for and early determining whether any specific medical intervention(s) to help preserve renal function in the remaining contralateral kidney becomes warranted.

Myocardial fibrosis is defined as an increased amount of collagen in the myocardium relative to cardiac myocytes. Two main morphologic patterns are recognized: 1) replacement fibrosis, which occurs in response to myocyte necrosis (myocardial scarring); and 2) interstitial fibrosis, which is usually a diffuse process and has been shown to be reversible and treatable. Replacement and interstitial fibrosis often coexist and are a constant feature of pathologic cardiac remodeling. In the last twenty years, there has been significant interest in developing objective non-invasive methods to identify and quantitatively assess myocardial fibrosis in vivo, both for diagnostic purposes and to improve stratification of patients. The present Review focuses on the morphologic patterns of myocardial fibrosis observed either at autopsy and heart transplant, or in vivo by non-invasive imaging techniques. Main aim is to provide clues for the differential diagnosis, with emphasis on entities whose diagnosis may be challenging. An update on the diagnostic and prognostic role of imaging, along with recent data on available biomarkers, is also proposed.

Funding Acknowledgements Type of funding sources: None. Background In MVP, MAD has been associated with myocardial replacement fibrosis and arrhythmia, but the importance of interstitial fibrosis remains unknown. We aimed to evaluate the relationship between mitral annular disjunction (MAD) severity and myocardial interstitial fibrosis at the left ventricular (LV) base in patients with mitral valve prolapse (MVP), and to assess the association between severity of interstitial fibrosis and the occurrence of ventricular arrhythmic events Methods Thirty patients with MVP and MAD (MVP-MAD) underwent Cardiac Magnetic Resonance (CMR) with assessment of MAD length, late gadolinium enhancement (LGE), and basal segments myocardial extracellular volume (ECV). The control group included 14 patients with mitral regurgitation but no MAD (MR-NoMAD) and 10 patients with normal CMR (NoMR-NoMAD). Fifteen MVP-MAD patients underwent 24h-Holter monitoring. Results LGE was observed in 47% of MVP-MAD patients and absent in controls. ECV was higher in MVP-MAD (30 ± 3% vs 24 ± 3% MR-NoMAD, p Conclusion Increase in ECV, a marker of interstitial fibrosis, occurs in MVP-MAD even in the absence of LGE, and was correlated with MAD length and OHCA. ECV should be part of the CMR examination of MVP patients in an effort to better assess fibrous remodelling as it may provide additional value beyond the assessment of LGE in the arrhythmic risk stratification.

Summary Mixed pneumoconiosis is a pulmonary disease associated with several inhaled mineral irritants. Dust was found in the alveolar macrophages, alveolar and bronchial walls and pulmonary interstitial tissue of two female coyotes (Canis latrans). The dust contained large amounts of silica, coal, iron and copper particles, which were associated with severe pulmonary disease. Lung injury in the animals was characterized by pulmonary nodules, severe interstitial fibrosis, alveolar hyperplasia and bone formation within alveolar spaces. Coyotes inhaled mineral dust while roaming a field close to three mineral extraction zones. To our knowledge, this is the first report of the concomitant inhalation of multiple minerals in association with diffuse pulmonary ossification in the pulmonary parenchyma of two wild canine animals.

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a clinical entity defined by interstitial fibrosis with tubular damage, bland urinalysis and progressive kidney disease. Mutations in UMOD and MUC1 are the most common causes of ADTKD but other rarer (REN, SEC61A1), atypical (DNAJB11) or heterogeneous (HNF1B) subtypes have been described. Raised awareness, as well as the implementation of next-generation sequencing approaches, have led to a sharp increase in reported cases. ADTKD is now believed to be one of the most common monogenic forms of kidney disease and overall it probably accounts for ∼5% of all monogenic causes of chronic kidney disease. Through international efforts and systematic analyses of patient cohorts, critical insights into clinical and genetic spectra of ADTKD, genotype–phenotype correlations as well as innovative diagnostic approaches have been amassed during recent years. In addition, intense research efforts are addressed towards deciphering and rescuing the cellular pathways activated in ADTKD. A better understanding of these diseases and of possible commonalities with more common causes of kidney disease may be relevant to understand and target mechanisms leading to fibrotic kidney disease in general. Here we highlight recent advances in our understanding of the different subtypes of ADTKD with an emphasis on the molecular underpinnings and its clinical presentations.

Made available in DSpace on 2022-04-28T19:47:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Background: A low supply of donated organs led to the expansion of criteria for kidney transplantation (KT), and the impact on late glomerular function rates (eGFR) is still uncertain. This study aimed to correlate the histologic findings at time-zero biopsy (TzB) with the final eGFR, to identify criteria that could help achieve a more thorough preimplantation evaluation of the organ. Methods: Records from 395 adult deceased KTs were reviewed. TzBs were analyzed considering histologic criteria by compartment (vascular, interstitial, tubular, and inflammatory) and correlated with the eGFR after 1 year. Results: Among donors, 56.9% were men (mean age 39 years), with the main causes of death being brain trauma (44.2%) and stroke (46.0%). Histologic analysis of TzB revealed 6.0% of glomerulosclerosis; 18.8% presenting vascular alterations; interstitial fibrosis in 54.6%; tubular changes in 76.9%, and nonspecific inflammatory infiltrate in 2.3%. Linear regression analysis showed that the main histologic findings that had impact in the eGFR were interstitial fibrosis (P = .000), followed by tubular alterations (P = .036) and glomerulosclerosis (P = .008). Conclusions: Histologic variables like interstitial fibrosis and tubular alterations show the most significant negative correlation with final eGFR. The effect of glomerulosclerosis may not be as important as formerly suggested in the literature. Urology Department University of São Paulo State Nephrology Department University of São Paulo State Pathology Department University of São Paulo State Urology Department Unicamp

Background and Aims Molecular mechanisms implicated in the initial stages of inorganic phosphate (Pi) imbalance in chronic kidney disease (CKD) remain poorly understood.The aim of the study was to evaluate whether canonical Wnt pathway inhibitors (iWnt) involved in early response to Pi retention in CKD. Methods Mild CKD was induced by 3/4 nephrectomy (NE) in spontaneously hypertensive rats (SHR) fed rat chow diet containing 0.6 % phosphate. Controls were sham operated SHR (SO). Duration of experimental exposure (NE or SO) was 2 and 6 months. Serum levels of creatinine (Cr), inorganic phosphate (Pi), fractional Pi excretion (FEPi), intact parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), alfa-Klotho (KL), sclerostin (SOST) and Dickkopf-1 (DKK1) were measured. The following morphological characteristics by light microscopy of bone metaphysis and kidney tissues: the area of renal interstitial fibrosis (RF) (Masson's trichrome), bone matrix volume (MV), the active osteoblasts to trabecular cells number ratio (aOB/cells), eroded surface to bone surface ratio (ES/BS) (hematoxylin & eosin), and bone SOST and DKK1 proteins expression (by IHC) were analyzed and calculated quantitatively. Statistical comparisons among groups were performed using Mann–Whitney U-test and Kruskal-Wallis H-test. Results Serum Cr, RF and indices of Pi exchange in the experimental model corresponded to early CKD (Table). Pi elevated in NE6 suggestive for its renal retention. KL level decreased (Table) in all experimental groups vs control. No differences were observed in serum levels FGF23 (p=0.62) and PTH (p=0.63). Serum SOST and DKK1 levels were significantly higher in NE6 group compared to SO6 (Table). The bone SOST and DKK1 expression increased in NE6 compared to SO6 (Figure). aOB/cells were lower in NE2, SO6 and NE6 vs SO2 (all p-values Conclusion Increased serum levels of sclerostin and Dickkopf-1 and their bone expression are apparent in early stages of experimental CKD associating with hyperphosphatemia. Alterations of bone resorption and osteoblast depopulation occurred before the increase of serum Pi likely reflecting incipient stages of renal Pi retention. These molecular and cellular events seem to be independent of systemic FGF23 and PTH response.

Background and Aims Gut microbiota is considered an important factor affecting oxalate handling in the intestine. It has been demonstrated that intestinal oxalate secretion provides a complementary route of excretion, and it becomes more evident when kidney function declines. A diversity of gut oxalate-degrading bacteria (ODB) has been hypothesized to play a role in this process. However, there is a general lack of research on the long-term effects of acute kidney injury (AKI) on ODB and their total oxalate-degrading activity (ODA) in fecal microbiota. In this study, we evaluated whether renal dysfunction could affect intestinal ODB and their total ODA in a rat model of glycerol-induced AKI. Method The Male Wistar rats (200-300 g, n=20) on oxalate-free diet were randomly divided into 2 groups. After 24-h of water deprivation, Group 1 (n=10) received an intramuscular injection of 50% glycerol (10 ml/kg of body weight), and Group 2 (n=10) served as control. The numbers of ODB (incubated in a highly selective Oxalate Medium and determined using culture method) and total fecal ODA were measured after injection on days 7 and 70. The method of redoximetric titration with a KMnO4 solution was adopted to evaluate total ODA in fecal microbiota; the results were expressed as % of oxalate degradation per 0.01 g of feces. Renal injury was assessed by histopathological examination, serum creatinine and daily proteinuria levels after removing the animals from the experiment on day 70. Cortical interstitial fibrosis was measured by computerized image analysis on sections stained with picrosirius red. The median (Me) and the interquartile ranges (Q25; Q75) were calculated and compared using the nonparametric Mann-Whitney test. The Spearman correlation coefficient was used to evaluate association between the examined parameters. Results The obtained results demonstrated: 1) after glycerol injection on day 7, no differences were found in the numbers of ODB and total fecal ODA between the experimental and control groups: 5.9 (5.4-6.0) vs 6.0 (5.4-6.4) CFU/g, p=0.65 and 2.0 (0.1-5.0) vs 2.5 (2.0-9.0) %/0.01g, p=0.24, respectively; 2) after AKI initiation on day 70, the numbers of ODB and total fecal ODA were significantly lower in Group I compared with control Group II (Fig. 1); 3) the higher percentage of renal interstitial fibrosis was, the higher total fecal ODA occurred in the experimental rats (Fig. 2). In addition, the number of ODB in feces in Group 1 had an inverse association with serum creatinine (r=-0.52, p=0.006) and 24-h proteinuria levels (r=-0.86, p Conclusion AKI had the long-term negative effects on the quantitative and qualitative characteristics of ODB in fecal microbiota in rats. Moreover, the results of our study confirmed an increasing trend in total fecal ODA according to the aggravation of renal interstitial fibrosis in rats.

Background and Aims Renal involvement is a severe manifestation of ANCA-associated vasculitis. Patients often progress to end-stage renal disease. The potential for renal recovery after a first flare has seldom been studied. Our objectives were to describe the evolution of the estimated glomerular filtration rate (eGFR) and identify factors associated with the change in eGFR between diagnosis and follow-up at 3 months (ΔeGFRM0–M3) in a cohort of patients with a first flare of pauci-immune glomerulonephritis. Methods This was a retrospective study over the period 2003–2018 of incident patients in the Nord-Pas-de-Calais (France). Patients were recruited if they had a first histologically-proven flare of pauci immune glomerulonephritis with at least 1 year of follow up. Kidney function was estimated with MDRD-equation and analysed at diagnosis, 3rd, 6th and 12th months. The primary outcome was ΔeGFRM0–M3. Factors evaluated were histological (Berden classification, interstitial fibrosis, percentage of crescents), clinical (extra-renal manifestations, sex, age) or biological (severity of acute kidney injury, dialysis, ANCA subtype). Results One hundred and seventy-seven patients were included. The eGFR at 3 months was significantly higher than at diagnosis (mean ± standard deviation, 40 ± 24 vs 28 ± 26 ml/min/1.73 m2, p < 0.001), with a ΔeGFRM0–M3 of 12 ± 19 ml/min/1.73 m2. The eGFR at 12 months was higher than at 3 months (44 ± 13 vs 40 ± 24 ml/min/1.73m2, p = 0.003). The factors significantly associated with ΔeGFRM0–M3 in univariate analysis were: sclerotic class according to Berden classification, percentage of interstitial fibrosis, percentage of cellular crescents, acute tubular necrosis, neurological involvement. The factors associated with ΔeGFRM0–M3 in multivariate analysis were the percentage of cellular crescents and neurological involvement. The mean increase in eGFR was 2.90 ± 0.06 ml/min/1.73m2 for every 10-point gain in the percentage of cellular crescents. ΔeGFRM0–M3 was not associated with the risks of end-stage renal disease or death in long-term follow-up. Conclusions Early renal recovery after a first flare of pauci-immune glomerulonephritis occurred mainly in the first three months of treatment. The percentage of cellular crescents was the main independent predictor of early renal recovery.

Background and Aims Interstitial fibrosis / tubular atrophy (IFTA) is a common, irreversible and progressive form of chronic allograft injury, and it is considered a critical predictor of kidney allograft outcomes. Inflammation, both microvascular and interstitial, is on the contrary regarded as a reversible form of graft injury. Since treatments for rejection and other causes of graft dysfunction bear substantial toxicity and could have limited efficacy, the extent of irreversible graft scarring is a crucial information for the clinician, to evaluate risks and benefits of specific therapies. The diagnosis of kidney graft pathology is acquired through graft biopsy, which is an invasive procedure and can be subjected to sampling bias. Magnetic resonance imaging (MRI), especially with functional techniques, has emerged as a possibility for non-invasive estimation of tissue fibrosis; nevertheless, functional MRI is not widely available. Texture analysis MRI (TA-MRI) is a radiomic technique that provides a quantitative assessment of tissue heterogeneity from standard MRI images, generating features that can be fitted into a machine-learning model to assess their ability to predict clinical or histological parameters. Method Single-center cross-sectional observational cohort study enrolling kidney transplant recipients who underwent graft biopsy and graft MRI imaging within 6 months from biopsy, both on clinical indication, at the “Azienda Ospedaliero-Universitaria di Modena”, Italy. The study was approved by the local Ethical Committee (AOU0010167/20). The primary outcome was to identify the best TA-MRI features subset for estimation of IFTA > 50% in graft biopsy. Secondary outcomes were estimation of: IFTA > 25%, presence of total inflammation (ti) and microvascular inflammation (glomerulitis + peritubular capillaritis [g+ptc]). Graft biopsy was reported according to Banff 2017 system. Radiomic analysis was performed on axial T2 pre-contrast and T1 fat-suppressed post-contrast sequences. The whole renal parenchyma (PAR) was segmented and labelled on T2 and T1, renal cortex (COR) only on T2. After imaging preprocessing, PyRadiomics was used to extract radiomic features. After removal of shape features, 93 features were included and reduced using LASSO regression to produce radiomic signatures. These were introduced in Machine Learning (ML) models to test the association with outcomes. Results are reported as AUC and a value of sensitivity and specificity. Results Sixty patients were included in the study, and 67 graft biopsy – graft MRI pairs were available for analysis. Demographic and clinical characteristics of enrolled patients are depicted in table 1; histological diagnosis and main Banff histological parameters from graft biopsies in table 2. Among ML models, three showed an acceptable performance. T2 COR “firstorder_minimum/firstorder_range/glrlm_run_entropy” for IFTA>50% (AUC=0.77, sensitivity=73%, specificity=71%), T1 PAR “firstorder_energy” for IFTA>25% (AUC=0.71, sensitivity=74%, specificity=51%), T1 PAR “firstorder_energy/gldm_small_dependence_low_gray_level_emphasis” for g+ptc >0 (AUC=0.74, sensitivity= 78%, specificity=68%); see figures 1–3. No acceptable prediction was detected for ti >0. Conclusion Our study shows that TA-MRI feature signatures can predict the degree of IFTA in graft biopsies, with an acceptable diagnostic performance. These results suggest to further investigating TA-MRI from standard MRI sequences as potential tool to assess graft chronic parenchymal injury. Moreover, since graft biopsy results can be jeopardized by limited sample size, we hypothesize that evaluation of IFTA through TA-MRI could provide more comprehensive information regarding the whole parenchyma. To test this hypothesis, we are currently evaluating the association of TA-MRI radiomic features and baseline eGFR and eGFR variation over time.

Background and Aims Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in older white adults, with an incidence of 12 cases per millions of people per year. Primary MN (PMN, 75%-80% of MNs) is an organ-specific autoimmune disease caused by antibodies anti-PLA2R and anti-THSD7A. Regardless of treatment one third of patients progresses to end-stage renal disease and two third develop non-progressive chronic kidney disease. Renal biopsy is the gold standard for MN diagnosis. Several clinical and biochemical markers have been associated with the risk of progressive loss of kidney function while contrasting results have been obtained by the few studies which have examined the prognostic value of histologic findings. In this study the clinical outcome of patients with PMN has been considered based on the prognostic value of histological findings. Method Forty-nine patients with PMN of our Nephrology Unit at Padova University Hospital from 2003 to 2018 were considered. 16 patients were excluded from the study due to missing data. Age, comorbidities, proteinuria (g/day) and renal function (eGFR, CKD-EPI) were collected. eGFR decline and decrease of proteinuria were used as clinical outcomes. The follow-up was considered from renal biopsy to the last visit (in absence of GFR decline or decrease in proteinuria). Histological grading (0-3) was assigned to parameters (glomerulosclerosis (GS), tubular atrophy (TA), interstitial fibrosis (IF), vascular hyalinosis (VH)) and were evaluated separately or in combination (as GSTIV score). Morphometric analysis was used to quantify IF and expressed in percentage as the mean of area covered by pixel. Statistical analysis was performed using Fisher’s exact test and Mann-Whitney U-test where appropriate. Cox regression analyses (univariate and multivariate) were performed to identify variables associated with both renal outcomes and p ROC curves were used to determine interstitial fibrosis cut-off values predictive for both outcomes. Area under the curve (AUC) between 0.8 and 1.0 was considered as significant. Diagnostic accuracy was assessed by Specificity (Sp), Sensibility (Se), positive (PPV) and negative (NPV) predictive values and positive (LR+) and negative (LR-) likelihood ratios. Results Patients with no decrease of proteinuria had a greater degree of IF vs those with a full response (p=0.006). Univariate Cox analyses identified age ≥65 years (HR 4.92), pre-existing CKD (HR 12.98) and IF (HR3.05) as significant predictors of renal function decline in all patients. Multivariate Cox analysis confirmed these variables (age ≥65 years HR 3.05, CKD HR 6.35, IF HR 3.03). In patients without CKD only IF was significantly associated with eGFR decline in both Cox univariate and multivariate analysis (HR 4.34 and 5.05 respectively). ROC analysis showed that IF threshold of 17.80% identified patients with eGFR reduction (AUC 0.65, Se 0.50, Sp 0.79, PPV 0.75, NPV 0.45, LR+ 2.38, LR-0.63) and IF threshold of 18.04% the lack of proteinuria reduction (AUC 0.78, Se 0.70, Sp 0.83, PPV 0.67, NPV 0.80, LR+ 4.12, LR- 0.36). Conclusion Our study shows that IF could be used as a histologic predictor of renal and proteinuria outcomes. Biopsy report should therefore also include quantitative IF data that could be helpful for the choice of a more appropriate therapeutic approach.