Interstitial Fibrosis And Tubular Atrophy Research Articles

MO648SERUM SOLUBLE UROKINASE PLASMINOGEN ACTIVATOR RECEPTOR IN PATIENTS WITH DIABETIC KIDNEY DISEASE

Abstract Background and Aims Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide, associated with significant cardiovascular morbidity and mortality. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker associated with inflammation, endothelial dysfunction and kidney disease. There is a lack of studies that investigate the role of suPAR in patients with DKD. Our aim was to assess the level of serum suPAR and to evaluate its association with kidney function, proteinuria and histological lesions in patients with DKD. Method We performed a cross-sectional study on 75 patients with DKD evaluated in our department between 2019 and 2020. Inclusion criteria were: age> 18 years, diagnosis of type 1 or type 2 diabetes mellitus, DKD and absence of malignancy, autoimmune disease, infectious disease and liver disease. Demographical, clinical and laboratory parameters were collected at the time of admission. A subset analysis was performed on 28 patients with biopsy- proven diabetic nephropathy (DN) to investigate the association of serum suPAR with histological lesions. Kidney function was evaluated based on serum creatinine and estimated with CKD-EPI formula, proteinuria was reported as 24h proteinuria and albumin/creatinine ratio (ACR) and serum suPAR levels were measured with a solid-phase ELISA kit. The detection range of the kit was 12 -360 pg/ml (7.8- 500). Results Among the 75 patients, mean age was 57.9±12.2 years, male was the dominant gender (65.3%), mean BMI was 30.7±5.5 kg/m2, most patients had hypertension (97.3%) and 22.7% were active smokers. Sixty six out of 75 patients (88%) had type 2 diabetes and the median duration of diabetes was 180 months (120- 240). Median values of estimated glomerular filtration rate (eGFR), 24h proteinuria and ACR were 24.3 ml/min (15- 36), 4.8 g/24h (1.9- 7.1) and 2000 mg/g, respectively. Median serum level of suPAR at the time of evaluation was 2857.2 pg/ml (1916.4- 3700.1). Its level was positively correlated with duration of diabetes (r= 0.278, p= 0.01), eGFR (r= 0.634, p< 0.001), 24h proteinuria (r= 0.490, p< 0.001), ACR (r= 0.524, p< 0.001) and negatively correlated with urine specific gravity (r= -0.284, p= 0.01). In the subset analysis on 28 patients with biopsy-proven DN, median suPAR level was 2474 pg/ml (1782-3745) and was positively correlated with DN class (r= 0.493, p=0.008) and interstitial fibrosis and tubular atrophy (IFTA) score (r= 506, p=0.006), but not with interstitial inflammation, arteriolar hyalinosis or arteriolosclerosis. Conclusion Our study showed a high serum level of suPAR in patients with DKD and its association with duration of diabetes, urinary specific gravity, kidney function and proteinuria. We also found a positive correlation with severity of glomerular lesions and IFTA.

Development and Validation of a Deep Learning Model to Quantify Interstitial Fibrosis and Tubular Atrophy From Kidney Ultrasonography Images

Interstitial fibrosis and tubular atrophy (IFTA) is a strong indicator of decline in kidney function and is measured using histopathological assessment of kidney biopsy core. At present, a noninvasive test to assess IFTA is not available. To develop and validate a deep learning (DL) algorithm to quantify IFTA from kidney ultrasonography images. This was a single-center diagnostic study of consecutive patients who underwent native kidney biopsy at John H. Stroger Jr. Hospital of Cook County, Chicago, Illinois, between January 1, 2014, and December 31, 2018. A DL algorithm was trained, validated, and tested to classify IFTA from kidney ultrasonography images. Of 6135 Crimmins-filtered ultrasonography images, 5523 were used for training (5122 images) and validation (401 images), and 612 were used to test the accuracy of the DL system. Kidney segmentation was performed using the UNet architecture, and classification was performed using a convolution neural network-based feature extractor and extreme gradient boosting. IFTA scored by a nephropathologist on trichrome stained kidney biopsy slide was used as the reference standard. IFTA was divided into 4 grades (grade 1, 0%-24%; grade 2, 25%-49%; grade 3, 50%-74%; and grade 4, 75%-100%). Data analysis was performed from December 2019 to May 2020. Prediction of IFTA grade was measured using the metrics precision, recall, accuracy, and F1 score. This study included 352 patients (mean [SD] age 47.43 [14.37] years), of whom 193 (54.82%) were women. There were 159 patients with IFTA grade 1 (2701 ultrasonography images), 74 patients with IFTA grade 2 (1239 ultrasonography images), 41 patients with IFTA grade 3 (701 ultrasonography images), and 78 patients with IFTA grade 4 (1494 ultrasonography images). Kidney ultrasonography images were segmented with 91% accuracy. In the independent test set, the point estimates for performance matrices showed precision of 0.8927 (95% CI, 0.8682-0.9172), recall of 0.8037 (95% CI, 0.7722-0.8352), accuracy of 0.8675 (95% CI, 0.8406-0.8944), and an F1 score of 0.8389 (95% CI, 0.8098-0.8680) at the image level. Corresponding estimates at the patient level were precision of 0.9003 (95% CI, 0.8644-0.9362), recall of 0.8421 (95% CI, 0.7984-0.8858), accuracy of 0.8955 (95% CI, 0.8589-0.9321), and an F1 score of 0.8639 (95% CI, 0.8228-0.9049). Accuracy at the patient level was highest for IFTA grade 1 and IFTA grade 4. The accuracy (approximately 90%) remained high irrespective of the timing of ultrasonography studies and the biopsy diagnosis. The predictive performance of the DL system did not show significant improvement when combined with baseline clinical characteristics. These findings suggest that a DL algorithm can accurately and independently predict IFTA from kidney ultrasonography images.

Deep-Learning–Driven Quantification of Interstitial Fibrosis in Digitized Kidney Biopsies

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.

An automatic framework for fusing information from differently stained consecutive digital whole slide images: A case study in renal histology

Objective: This article presents an automatic image processing framework to extract quantitative high-level information describing the micro-environment of glomeruli in consecutive whole slide images (WSIs) processed with different staining modalities of patients with chronic kidney rejection after kidney transplantation.Methods: This four-step framework consists of: 1) approximate rigid registration, 2) cell and anatomical structure segmentation 3) fusion of information from different stainings using a newly developed registration algorithm 4) feature extraction.Results: Each step of the framework is validated independently both quantitatively and qualitatively by pathologists. An illustration of the different types of features that can be extracted is presented.Conclusion: The proposed generic framework allows for the analysis of the micro-environment surrounding large structures that can be segmented (either manually or automatically). It is independent of the segmentation approach and is therefore applicable to a variety of biomedical research questions.Significance: Chronic tissue remodelling processes after kidney transplantation can result in interstitial fibrosis and tubular atrophy (IFTA) and glomerulosclerosis. This pipeline provides tools to quantitatively analyse, in the same spatial context, information from different consecutive WSIs and help researchers understand the complex underlying mechanisms leading to IFTA and glomerulosclerosis.

Impaired ATG16L-Dependent Autophagy Promotes Renal Interstitial Fibrosis in Chronic Renal Graft Dysfunction Through Inducing EndMT by NF-κB Signal Pathway.

Chronic renal graft dysfunction (CAD) is caused by multiple factors, including glomerular sclerosis, inflammation, interstitial fibrosis and tubular atrophy (IF/TA). However, the most prominent elements of CAD are IF/TA. Our studies have confirmed that endothelial-mesenchymal transition (EndMT) is an important source to allograft IF/TA. The characteristic of EndMT is the loss of endothelial marker and the acquisition of mesenchymal or fibroblastic phenotypes. Autophagy is an intracellular degradation pathway that is regulated by autophagy-related proteins and plays a vital role in many fibrotic conditions. However, whether or not autophagy contributes to fibrosis of renal allograft and how such mechanism occurs still remains unclear. Autophagy related 16 like gene (ATG16L) is a critical autophagy-related gene (ARG) necessary for autophagosome formation. Here, we first analyzed kidney transplant patient tissues from Gene Expression Omnibus (GEO) datasets and 60 transplant patients from our center. Recipients with stable kidney function were defined as non-CAD group and all patients in CAD group were histopathologically diagnosed with CAD. Results showed that ATG16L, as one significant differential ARG, was less expressed in CAD group compared to the non-CAD group. Furthermore, we found there were less autophagosomes and autolysosomes in transplanted kidneys of CAD patients, and downregulation of autophagy is a poor prognostic factor. In vitro, we found out that the knockdown of ATG16L enhanced the process of EndMT in human renal glomerular endothelial cells (HRGECs). In vivo, the changes of EndMT and autophagic flux were then detected in rat renal transplant models of CAD. We demonstrated the occurrence of EndMT, and indicated that abundance of ATG16L was accompanied by the dynamic autophagic flux change along different stages of kidney transplantation. Mechanistically, knockdown of ATG16L, specifically in endothelial cells, reduced of NF-κB degradation and excreted inflammatory cytokines (IL-1β, IL-6 and TNF-α), which could facilitate EndMT. In conclusion, ATG16L-dependent autophagic flux causing by transplant showed progressive loss increase over time. Inflammatory cytokines from this process promoted EndMT, thereby leading to progression of CAD. ATG16L served as a negative regulator of EndMT and development of renal graft fibrosis, and autophagy can be explored as a potential therapeutic target for chronic renal graft dysfunction.

The extent of tubulointerstitial inflammation is an independent predictor of renal survival in lupus nephritis.

Lupus nephritis (LN) is a major complicationin patients with systemic lupus erythematosus (SLE). Tubulointerstitial injury is an inflammatory process that, if not attenuated, can promote renal damage. Despite this, the current 2003 ISN/RPS "glomerulocentric" classification does not include a score for tubulointerstitialinjury. We sought to establish predictors for tubulointerstitial injury and to determine their influence on renal outcomes. This is a retrospective study of a cohort of 166 patients with biopsy-proven LN diagnosed in a Spanish referral center, with a median follow-up of 86months. Chronic tubulointerstitiallesions were defined as interstitial fibrosis and tubular atrophy (IF/TA), whereas tubulointerstitialinflammation (TII) was defined as an acute interstitiallesion. Activity (0-24) and chronicity (0-12) indices were assigned. Composite outcome, definedas advanced CKD or development of kidney failure. The prevalenceof tubulointerstitiallesions was 69.3%. Eighty-one of the biopsies had features of tubulointerstitial inflammationand only 6 of these81 (7%) patients had moderate/severe tubulointerstitial inflammation. The incidence ofinterstitial fibrosis and tubular atrophywas 56.6%. Renal survival was shorter in patients with moderate/severe as compared with absent/mild interstitial fibrosis and tubular atrophy(median: 15-19years, p = 0.009). In the Cox regression model, the grade ofinterstitial fibrosis and tubular atrophy was independently associated with shorter renal survival (hazard ratio: 3.9, 95% CI 1.4-10.5; p = 0.008) after adjusting for degree of IF/TA and hypertension or diabetes. The extent of tubulointerstitial inflammation emerged as an independent predictor of renal survival after adjusting for the grade ofinterstitial fibrosis and tubular atrophy and co-morbid conditions includinghypertension or diabetes. Regarding disease duration at the time of renal biopsy, no significant association was found between the interstitial fibrosis and tubular atrophygroups. The results reported herein need to be validated in future studies to include also groups of patients who usually have a worse prognosis. Consensus on histological classification is needed to aid in definingprognosis.

Searching for the origin of the myofibroblast one cell at a time

Chronic kidney disease (CKD), regardless of the initial injury, is often characterized by relentless progression with the ultimate development of tubular atrophy, interstitial fibrosis, and glomerulosclerosis. The extent of tubulointerstitial fibrosis is the morphological parameter most closely associated with decreased glomerular filtration rate.1 Interstitial fibrosis and tubular atrophy (IF/TA) almost invariably develop in parallel, and increased IF/TA is a morphological indicator of poor prognosis across the full spectrum of kidney diseases.

Expression of VWF and Interferon γ in renal allograft biopsies and correlation with inflammatory cells; Single center experience

Objective: Gene expression profiling by microarrays or RT PCR had been studied in certain western centers to enhance the diagnostic accuracy of allograft biopsy, however, such sophisticated tests are difficult to apply in developing countries. This study was conducted to evaluate the expression of von Willebrand factor (VWF) and Interferon-gamma (IFNγ) as an end PCR product in renal allograft biopsy with different pathological categories.
 Methods: Forty-nine indicated renal allograft biopsies were analyzed histologically by the Banff 2017 classification, inflammatory cell infiltration was analyzed by immunohistochemistry study for CD4, CD8, CD16, and CD68 markers, and a fresh tissue used for molecular study.
 Results: The biopsy findings were acute T-cell mediated rejection (A- TCMR) 30.6%, interstitial fibrosis and tubular atrophy (IF/TA) 22.4%, C4d-Transplant glomerulopathy (TG) 12.2%, calcineurin inhibitor toxicity (CNI) 10.2%, C4d+antibody mediated rejection (AMR) 10.2% and normal histology 14.3%. The only significant difference in VWF expression was between acute TCMR and normal, P=0.01, Spearman's correlation also showed a significant relationship between VWF and acute TCMR (r=0.53, P=0.01), and VWF was found to correlate with the numbers of interstitial CD4+ (r=0.29, P=0.03) and CD68+ (r=0.37, P=0.007) cells. IFNγ expression was significant in acute TCMR versus normal, P=0.009. Spearman's pair-wise testing showed that INFγ correlated with CD8 in both the glomerular (r=0.38, P=0.006) and interstitial (r=0.30, P=0.04) compartments and with CD16+ interstitial cells (r=0.36, P=0.01).
 Conclusion: our molecular and IHC data distinguish acute TCMR from other forms of transplant pathology and mildly dysfunctional kidneys with normal histology.

Rate, Factors, and Outcome of Delayed Graft Function After Kidney Transplantation of Deceased Donors

BackgroundDelayed graft function (DGF) is a frequent complication after kidney transplantation affecting long-term outcome. Patients and methodsA total of 525 consecutive recipients (age 54.2 .. 13.4 years, 33% female) of kidneys from deceased donors transplanted between 2005 and 2012 were retrospectively examined. DGF was defined as the need of dialysis within the first week after transplantation. ResultsDGF developed in 21.1% (n = 111). Factors associated with DGF (P ..± .035, respectively) were recipient body mass index, C-reactive protein of the recipient, residual diuresis, cold ischemia time, donor age, and diuresis in the first hour after transplantation. Median duration of DGF was 16 (2-66) days. Patients after DGF had a significantly lower GFR compared with recipients without DGF either after 3 (32.9 .. 16.5 vs 46.3 .. 18.4 mL/min/1.73 m2) or after 12 months (38.9 .. 19.3 vs 48.6 .. 20.4 mL/min/1.73 m2, P < .001, resp.). During DGF, 12.4% developed BANFF II and 18.0% BANFF I rejection, 20.2% had signs of transplant glomerulitis (first biopsy), and 16.2% (n = 18) remained on dialysis. ConclusionDGF affects 1 out of 5 kidney transplants from deceased donors. Minimizing modifiable risk factors, in particular immunologic risk, may ameliorate the incidence and outcome of DGF. The outcome of DGF depends mainly on the diagnosis of any rejection and worsens upon detection of transplant glomerulitis and pronounced interstitial fibrosis and tubular atrophy (IFTA).

A Distributed System Improves Inter-Observer and AI Concordance in Annotating Interstitial Fibrosis and Tubular Atrophy.

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.

Clinico-histomorphologic Characteristics of Lupus Nephritis, Experience at a Center at Dhaka.

Lupus nephritis (LN) is one of the most serious systemic lupus erythematosus complications since it is the major predictor of poor prognosis. We present the clinico-histomorphologic characteristics of LN at a center in Dhaka. The study group comprised diagnosed cases of LN on core-needle renal biopsy specimens received in the Department of Histopathology, Armed Forces Institute of Pathology, Dhaka, from January 2018 to June 2019. Histological evaluation and direct immunofluorescence (DIF) study was carried out on each specimen. Each case was classified according to the International Society for Nephrology/Renal Pathology Society (ISN/RPS) Classification 2003 of LN. A total of 104 (9.20%) LN cases were included of total 1130 nonneoplastic renal biopsy specimens. The mean age was 28.29 ± 12.24 years, with a male:female ratio of 1:4.47. According to the ISN/RPS 2003 classification, most of the LN belong to class IV (42, 40.38%), followed by class III (27, 25.96%), class II (22, 21.15%), and so on. The mean age of class IV LN was 25.95 ± 10.15 years, with M:F = 1:4.25. The mean urinary total protein (UTP) was 4.62 ± 4.47 g/24 h and the mean serum creatinine was 1.87 ± 1.12 mg/dL. On histopathology, 22 (52.38%) had crescent formation, 27 (64.28%) had wire loop formation with subendothelial thrombi, and 30 (71.42%) had necrotizing lesion. Interstitial fibrosis and tubular atrophy (IFTA) was ≥25% in eight (19.04%) class IV LN. Among the subclasses, most common was IV-G (A/C) - 16 (38.09%), followed by IV-S (A/C) - nine (21.42%) and IV-S (A) and IV-G (A) each eight (19.04%). In four (9.52%) cases, class IV + V lesion was found. The mean age of class III LN was 26 ± 11.02 years, with a male:female of 1:26. The mean UTP was 3.45 ± 2.4 and serum creatinine was 1.71 ± 1.51. Among these, crescent was found in eight (29.63%) cases, wire loop and subendothelial thrombi in 11 (37.04%) cases, and necrotizing lesions in eight (29.63%) cases. IFTA was >25% in 14.81% of cases of class III LN. Among 27 class III LN, 17 (62.96%) were classified as III (A) and 10 (37.04%) as III (A/C). Two class III LN had an association with class V and two have presented with TMA. The mean age of class II LN was 29.95+ 12.26 years, with M:F = 1:2.66. UTP was 3.53 ± 2.43 g/24 h and serum creatinine was 1.52 ± 1.5 mg/dL for class II LN. Histologically, these cases had focal/diffuse mesangial proliferation with 25% IFTA in 9.09% of cases. One of the class II LN had associated amyloidosis. Among class V LN, the mean age was 45.12 + 13.64 years, with M:F = 1:3. The mean UTP was 4.06 ± 1.71 g/24 h and serum creatinine was 1.64 ± 0.94 mg/dL. Histologically, 37.5% had >25% IFTA. The mean age of class I lesion was 27.25 ± 17.42 years with equal number of males and females. The mean serum creatinine level was 0.65 ± 0.18 mg/dL and UTP was 2.71 ± 2.3 g/24 h for class I lesion. Only one class VI LN case was found which had IFTA 40% and presented with generalized edema. On DIF, among 100 cases, 86 were found with full-house immune deposits of different intensity; IgM was lacking in 10 cases and IgA was lacking in seven cases, while three cases lacked C3 deposits. The mean activity index was 7.10 and the mean chronicity index was 3.23 among 69 cases of proliferative LN. Among different histological classes of LN, the prevalence of class IV was more in this study which had the most severe form of clinical presentation, biochemical parameters (raised serum creatinine level), and histological findings (crescent formation and IFTA).

Autologous bone marrow-derived mesenchymal stem cells for interstitial fibrosis and tubular atrophy: a pilot study

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

INCIDENCE OF CYTOMEGALOVIRUS DISEASE IN KIDNEY TRANSPLANT RECIPIENTS RECEIVING EVEROLIMUS AND REDUCED TACROLIMUS DOSES: A COHORT RETROSPECTIVE ANALYSIS

Introduction: Cytomegalovirus (CMV) is the most common viral pathogen occurring in postrenal transplantation. CMV infection usually develops during the first few months after transplantation. The success of CMV prophylaxis with antivirals has resulted in a decrease in the incidence of CMV infection. However, CMV remains a significant pathogen, associated with allograft rejection and loss, mortality, interstitial fibrosis and tubular atrophy (IF/TA) in protocol biopsies, and increased post-transplant costs. Purpose: To determine the incidence of cytomegalovirus disease in kidney transplant recipients receiving Everolimus and reduced Tacrolimus doses. Material and Methods: All low immunological risk patients, >18 years old whom received kidney transplantation at Santa Casa de Misericordia de Juiz de Fora between January 2013 and February 2017 were retrospectively assessed. The first group received induction therapy with Basiliximab, and the post-operative maintenance regimen included Tacrolimus, Mycophenolic acid and Prednisone (BAS/MPS), and the second group received Polyclonal antilymphocyte globulins (2,25mg/kg) as induction therapy, and then low dose of Tacrolimus (2mg/10kg/day), Everolimus and Prednisone as maintenance regimen (r-ATG/EVR). None of the patients received pharmacological prophylaxis or preemptive therapy against CMV. Results: Patients receiving EVR showed a lower incidence of CMV when compared to those receiving MPS (4.2% x 17.5%, p=0.005). There was an important difference in the time of hospitalization to treat CMV disease. Patients of the MPS stayed hospitalized for about 20 days more than the EVR group (p=0.005). There was no difference as to the incidence of rejection, delayed graft function or graft survival. Conclusion: Results from this trial conducted in low immunological risk kidney transplant recipients receiving no CMV prophylaxis demonstrated that EVR was associated to a decrease in CMV disease incidence when compared to MPS. These data suggest that kidney transplant recipients receiving EVR may not need CMV prophylaxis.

Long-Term Outcomes in 831 Kidney Transplant Recipients with 20 Years of Graft Function

An understanding of long-term outcomes for kidney transplant(KTx) recipients who survive with graft function beyond a specific time posttransplant is the first step in creating protocols to optimize care for current and improve outcomes for future recipients. We studied 831KTx recipients-580 living donor(LD); 251 deceased donor(DD)—with graft survival(GS) &gt;20 years. For primary LD recipients, 25-year patient survival(PS) was 83%; 35-year, 59%. Their 25-year death-censored graft survival(DCGS) was 89%; 35-year, 72%. DD recipients had lower PS(P&lt;0.01), DCGS(P&lt;0.01). After 20 years, two major causes of graft loss(GL) were death with function(DwF)(58%, LD; 58%, DD) and interstitial fibrosis and tubular atrophy(IFTA)(22%, LD; 23%, DD). Two major causes of DwF were cancer(31%, LD; 31%, DD) and cardiovascular disease(CVD)(19%, LD;17%, DD). Per multivariate analysis(MVA), risk factors for GL after 20 years in pre–calcineurin inhibitor(CNI) era were human leukocyte antigen(HLA) mismatches &gt;3 antigens, pretransplant type 1 diabetes mellitus(DM1); in CNI era, a history of rejection, female gender. New comorbidities after 20 years were common: CVD(13%, non-DM1;18%, DM1), infections(27%, non-DM1;37%, DM1), 20-29 years posttransplant. Cancer after 20 years included: nonmelanotic skin cancer,22%; solid organ,7%; post-transplant lymphoproliferative disease(PTLD),2%. To improve long-term outcomes, clinical trials on prevention, recognition, and treatment of new comorbidities are needed.

Urinary vitronectin identifies patients with high levels of fibrosis in kidney grafts

BackgroundIn kidney transplantation, fibrosis represents the final and irreversible consequence of the pathogenic mechanisms that lead to graft failure, and in the late stages it irremediably precedes the loss of renal function. The invasiveness of kidney biopsy prevents this condition from being frequently monitored, while clinical data are rather unspecific. The objective of this study was to find noninvasive biomarkers of kidney rejection.MethodsWe carried out proteomic analysis of the urinary Extracellular Vesicles (uEVs) from a cohort of kidney transplant recipients (n = 23) classified according to their biopsy-based diagnosis and clinical parameters as interstitial fibrosis and tubular atrophy (IFTA), acute cellular rejection (ACR), calcineurin inhibitors toxicity (CNIT) and normal kidney function (NKF).ResultsShotgun mass spectrometry of uEV-proteins identified differential expression of several proteins among these different groups. Up to 23 of these proteins were re-evaluated using targeted proteomics in a new independent cohort of patients (n = 41) classified in the same diagnostic groups. Among other results, we found a differential expression of vitronectin (VTN) in patients displaying chronic interstitial and tubular lesions (ci and ct mean > 2 according to Banff criteria). These results were further confirmed by a pilot study using enzyme-linked immunosorbent assay (ELISA).ConclusionUrinary vitronectin levels are a potential stand-alone biomarker to monitor fibrotic changes in kidney transplant recipients in a non-invasive fashion.

Analyses of AUC(0-12) and C0 Compliances within Therapeutic Ranges in Kidney Recipients Receiving Cyclosporine or Tacrolimus.

The AUC (area under the concentration time curve) is considered the pharmacokinetic exposure parameter best associated with clinical effects. Unfortunately, no prospective studies of clinical outcomes have been conducted in adult transplant recipients to investigate properly the potential benefits of AUC(0–12) monitoring compared to the C0-guided therapy. The aim of the present study was to compare two methods, C0 (through level) and AUC(0–12) (area under the concentration time curve), for assessing cyclosporine and tacrolimus concentrations. The study included 340 kidney recipients. The AUC(0–12) was estimated using a Bayesian estimator and a three-point limited sampling strategy. Therapeutic drug monitoring of tacrolimus performed by using AUC(0–12) and C0 showed that tacrolimus in most cases is overdosed when considering C0, while determination of the AUC(0–12) showed that tacrolimus is effectively dosed for 27.8–40.0% of patients receiving only tacrolimus and for 25.0–31.9% of patients receiving tacrolimus with MMF (mycophenolate mofetil). In the 1–5 years post-transplantation group, 10% higher CsA (cyclosporine) dose was observed, which was proportionate with a 10% higher AUC(0–12) exposure value. This indicates good compatibility of the dosage and the AUC(0–12) method. The Bland–Altman plot demonstrated that C0 and AUC(0–12) might be interchangeable methods, while the ROC (receiver operating characteristic) curve analysis of the C0/AUC(0–12) ratio in the tacrolimus-receiving patient group demonstrated reliable performance to predict IFTA (interstitial fibrosis and tubular atrophy) after kidney transplantation, with an ROC curve of 0.660 (95% confidence interval (CI): 0.576–0.736), p < 0.01. Moreover, AUC(0–12) and C0 of tacrolimus depend on concomitant medication and adjustment of the therapeutic range for AUC(0–12) might influence the results.

Anemia in Diabetic Patients Reflects Severe Tubulointerstitial Injury and Aids in Clinically Predicting a Diagnosis of Diabetic Nephropathy.

Objective A kidney biopsy is generally performed in diabetic patients to discriminate between diabetic nephropathy (DN) and non-diabetic kidney disease (NDKD) and to provide more specific treatments. This study investigated the impact of anemia on the renal pathology and the clinical course in patients who underwent a kidney biopsy. Methods We reviewed 81 patients with type 2 diabetes who underwent a percutaneous kidney biopsy. Patients were classified into two groups: isolated DN (DN group, n=30) and NDKD alone or concurrent DN (NDKD group, n=51) groups. The laboratory and pathological findings and clinical courses were investigated. Results In the NDKD group, membranous nephropathy was the most common finding (23.5%), followed by IgA nephropathy (17.6%) and crescentic glomerulonephritis (13.7%). In the logistic regression analysis, the absence of severe hematuria and presence of anemia were significantly associated with a diagnosis of DN. Akaike's information criterion (AIC) and net reclassification improvement (NRI) analyses revealed improved predictive performance by adding anemia to the conventional factors (AIC 100.152 to 91.844; NRI 27.0%). The tissues of patients in the DN group demonstrated more severe interstitial fibrosis and tubular atrophy (IF/TA) than those in the NDKD group (p<0.05) regardless of the rate of global glomerulosclerosis, and IF/TA was related to the prevalence of anemia (odds ratio: 7.31, 95% confidence interval: 2.33-23.00, p<0.01) according to a multivariable regression analysis. Furthermore, the isolated DN group demonstrated a poorer prognosis than the NDKD group. Conclusion DN is associated with anemia because of severe IF/TA regardless of the renal function, and anemia helps clinician discriminate clinically between isolated DN and NDKD.

Clinicopathological profile and outcomes of infection-related glomerulonephritis in adults.

Infection-related glomerulonephritis (IRGN) is an example of immune-mediated glomerular injury, with changing profile over the years. We analyzed the clinicopathological profile of IRGN from a single center. Adult renal biopsies between July 2018 and January 2020 were screened, and biopsies with IRGN were included. The demographic, clinical, and laboratory data up to 6 months were analyzed. 27 patients were included, with 63% having evidence of current/recent infection, Staphylococcus and Streptococcus being most common (29.4%). The mean eGFR at presentation was 16.7mL/min/1.73m2, with crescents in 70.4% of cases. 59.3% required dialysis, and 40.7% received steroids. Complete recovery was seen in 84.6%, while 11.1% developed chronic kidney disease, and 3.7% progressed to end-stage renal disease. Persistent proteinuria, hematuria, and hypertension at 6 months were seen in 11.1, 7.4, and 3.7%, respectively. There was significant negative correlation between renal recovery and history of diabetes, interstitial fibrosis and tubular atrophy (IFTA), glomerulosclerosis, and IgA deposits. There was no significant impact of steroid use on outcome. IRGN can have an aggressive course in adults, with renal recovery continuing beyond 3 months. IFTA, glomerulosclerosis, IgA deposits, and history of DM are significant negative predictors of clinical outcome, and there is no proven benefit of steroids.

A Rejection Gene Expression Score in Indication and Surveillance Biopsies Is Associated with Graft Outcome.

Rejection-associated gene expression has been characterized in renal allograft biopsies for cause. The aim is to evaluate rejection gene expression in subclinical rejection and in biopsies with borderline changes or interstitial fibrosis and tubular atrophy (IFTA). We included 96 biopsies. Most differentially expressed genes between normal surveillance biopsies (n = 17) and clinical rejection (n = 12) were obtained. A rejection-associated gene (RAG) score was defined as its geometric mean. The following groups were considered: (a) subclinical rejection (REJ-S, n = 6); (b) borderline changes in biopsies for cause (BL-C, n = 13); (c) borderline changes in surveillance biopsies (BL-S, n = 12); (d) IFTA in biopsies for cause (IFTA-C, n = 20); and (e) IFTA in surveillance biopsies (IFTA-S, n = 16). The outcome variable was death-censored graft loss or glomerular filtration rate decline ≥ 30 % at 2 years. A RAG score containing 109 genes derived from normal and clinical rejection (area under the curve, AUC = 1) was employed to classify the study groups. A positive RAG score was observed in 83% REJ-S, 38% BL-C, 17% BL-S, 25% IFTA-C, and 5% IFTA-S. A positive RAG score was an independent predictor of graft outcome from histological diagnosis (hazard ratio: 3.5 and 95% confidence interval: 1.1–10.9; p = 0.031). A positive RAG score predicts graft outcome in surveillance and for cause biopsies with a less severe phenotype than clinical rejection.

Proteomic Characterization of Urinary Extracellular Vesicles from Kidney-Transplanted Patients Treated with Calcineurin Inhibitors.

Use of immunosuppressive drugs is still unavoidable in kidney-transplanted patients. Since their discovery, calcineurin inhibitors (CNI) have been considered the first-line immunosuppressive agents, in spite of their known nephrotoxicity. Chronic CNI toxicity (CNIT) may lead to kidney fibrosis, a threatening scenario for graft survival. However, there is still controversy regarding CNIT diagnosis, monitoring and therapeutic management, and their specific effects at the molecular level are not fully known. Aiming to better characterize CNIT patients, in the present study, we collected urine from kidney-transplanted patients treated with CNI who (i) had a normal kidney function, (ii) suffered CNIT, or (iii) presented interstitial fibrosis and tubular atrophy (IFTA). Urinary extracellular vesicles (uEV) were enriched and the proteome was analyzed to get insight into changes happening during CNI. Members of the uroplakin and plakin families were significantly upregulated in the CNIT group, suggesting an important role in CNIT processes. Although biomarkers cannot be asserted from this single pilot study, our results evidence the potential of uEV as a source of non-invasive protein biomarkers for a better detection and monitoring of this renal alteration in kidney-transplanted patients.