scholarly journals Progression of Interstitial Fibrosis and Tubular Atrophy in Low Immunological Risk Renal Transplants Monitored by Sequential Surveillance Biopsies: The Influence of TAC Exposure and Metabolism

2021 ◽  
Vol 10 (1) ◽  
pp. 141
Author(s):  
Betty Chamoun ◽  
Irina B. Torres ◽  
Alejandra Gabaldón ◽  
Joana Sellarés ◽  
Manel Perelló ◽  
...  

The combination of tacrolimus (TAC) and mycophenolate is the most widely employed maintenance immunosuppression in renal transplants. Different surrogates of tacrolimus exposure or metabolism such as tacrolimus trough levels (TAC-C0), coefficient of variation of tacrolimus (CV-TAC-C0), time in therapeutic range (TTR), and tacrolimus concentration dose ratio (C/D) have been associated with graft outcomes. We explore in a cohort of low immunological risk renal transplants (n = 85) treated with TAC, mycophenolate mofetil (MMF), and steroids and then monitored by paired surveillance biopsies the association between histological lesions and TAC-C0 at the time of biopsy as well as CV-TAC-C0, TTR, and C/D during follow up. Interstitial inflammation (i-Banff score ≥ 1) in the first surveillance biopsy was associated with TAC-C0 (odds ratio (OR): 0.69, 95% confidence interval (CI): 0.50–0.96; p = 0.027). In the second surveillance biopsy, inflammation was associated with time below the therapeutic range (OR: 1.05 and 95% CI: 1.01–1.10; p = 0.023). Interstitial inflammation in scarred areas (i-IFTA score ≥ 1) was not associated with surrogates of TAC exposure/metabolism. Progression of interstitial fibrosis/tubular atrophy (IF/TA) was observed in 35 cases (41.2%). Multivariate regression logistic analysis showed that mean C/D (OR: 0.48; 95% CI: 0.25–0.92; p = 0.026) and IF/TA in the first biopsy (OR: 0.43, 95% CI: 0.24–0.77, p = 0.005) were associated with IF/TA progression between biopsies. A low C/D ratio is associated with IF/TA progression, suggesting that TAC nephrotoxicity may contribute to fibrosis progression in well immunosuppressed patients. Our data support that TAC exposure is associated with inflammation in healthy kidney areas but not in scarred tissue.

2021 ◽  
Vol 12 ◽  
Author(s):  
Samy Hakroush ◽  
Désirée Tampe ◽  
Philipp Ströbel ◽  
Peter Korsten ◽  
Björn Tampe

BackgroundAcute kidney injury (AKI) is a common and severe complication of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV), potentially leading to chronic kidney disease (CKD), end-stage renal disease (ESRD), or death. Pathogenic ANCAs, in particular proteinase 3 (PR3) and myeloperoxidase (MPO), trigger a deleterious immune response with intrarenal immune cell infiltration resulting in a pauci-immune necrotizing and crescentic glomerulonephritis (GN). However, a systematic analysis of intrarenal immune cell subtypes concerning neutrophils, eosinophils, plasma cells, and mononuclear cell infiltrates (macrophages, lymphocytes) in ANCA GN remains elusive. Therefore, we aimed to compare distinct immune cell infiltrates in association with clinicopathological findings in ANCA GN.MethodsA total of 53 kidney biopsies with ANCA GN at the University Medical Center Göttingen were retrospectively analyzed. Histological infiltrates of neutrophils, eosinophils, plasma cells, and mononucleated cells (macrophages, lymphocytes) were quantified as a fraction of the total area of inflammation.ResultsNeutrophilic infiltrates were associated with glomerular necrosis and severe kidney injury in ANCA GN. Among tubulointerstitial lesions, intrarenal neutrophils correlated with interstitial inflammation, tubulitis, and inflammation in areas of interstitial fibrosis/tubular atrophy (IFTA), representing active inflammatory lesions. Concerning eosinophils, infiltrates were associated with severe kidney injury, interstitial inflammation, and cellular casts independent of glomerular lesions, implicating a distinct role in inflammation and damage in ANCA GN. Plasma cell infiltrates correlated with tubulitis and interstitial fibrosis and were associated with renal replacement therapy during the short-term disease course. Finally, mononuclear cell infiltrates correlated with severe kidney injury and active histopathological lesions (glomerular crescents, interstitial inflammation, tubulitis, inflammation, and tubulitis in areas of IFTA) besides chronic lesions (interstitial fibrosis and tubular atrophy) in ANCA GN. Interestingly, intrarenal subtypes of immune cell infiltrates differed in MPO-ANCA versus PR3-ANCA GN and were associated with distinct glomerular and tubulointerstitial lesions, implicating different pathogenic mechanisms of kidney injury in ANCA subtypes.ConclusionOur observations imply distinct pathomechanisms contributing to inflammation and renal injury in MPO vs. PR3-associated ANCA GN and potentially contribute to new therapeutic targets in specific ANCA subtypes.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Betty Chamoun Huacon ◽  
Irina Torres ◽  
Alejandra Gabaldon ◽  
Néstor Toapanta ◽  
Joana Sellares ◽  
...  

Abstract Background and Aims Fast tacrolimus metabolizers (expressed as the blood concentration/ dose ratio; C / D; ng / mL * mg) showed poorer renal function at 2 years, a higher incidence of nephrotoxicity and BK polyomavirus infection. Greater variability of tacrolimus trough levels (CV) from six to twelve months is associated with the appearance of HLA antibodies, interstitial fibrosis / tubular atrophy (IFTA) progression and allograft loss. We evaluate the relationship between C / D, CV and IFTA progression. Method We evaluated a cohort of 87 low immunological risk renal transplants treated with prolonged-release tacrolimus, mycophenolate mofetil and steroids. We analyzed paired protocol biopsies at 4 and 18 months. Biopsies were evaluated according to the Banff classification and the progression of IFTA was defined as the difference of ci + ct score> 0 between 18 and 4 months. The C / D ratio was calculated as the average of the value recorded at 3, 6 and 12 months of follow-up. The tacrolimus CV between 6 and 12 months was calculated using all the available determinations. Results IFTA progression was observed in 36 cases (41%). In the univariate analysis, it was found that the progression of IFTA was associated with the ci + ct score at 4 months (0.92 ± 0.94 for progressors vs. 1.89 ± 1.26 not progressors, p = 0.0003), and with the average of the C / D ratio (1.70 ± 0.73 for progressors vs. 2.28 ± 1.25 not progressors; p = 0.0144, table 1). An independent association between the C/D ratio and the progression of IFTA was observed in the multivariate analysis (OR: 0.42; 95% CI: 0.22-0.82, p = 0.027). Conclusion The results of our work suggest that fast tacrolimus metabolizers (lower C / D ratio) are more susceptible to the nephrotoxic effect of tacrolimus.


Nephron ◽  
2020 ◽  
pp. 1-6
Author(s):  
Tomokazu Shimizu

<b><i>Aim:</i></b> We aimed to perform a clinicopathological analysis of cases presenting with borderline changes (BC) after renal transplantation and discuss whether BC might be clinically or pathologically important. <b><i>Materials and Methods:</i></b> BC was diagnosed in 22 renal allograft biopsy specimens obtained from 20 renal transplant recipients between April 2010 and March 2019 after follow-up at the Department of Transplant Surgery, Kidney Center, Toda Chuo General Hospital. <b><i>Results:</i></b> BC was diagnosed at a median of 500 days following transplantation. Among the 22 renal allograft biopsy specimens showing evidence of BC, tubulitis was observed in all specimens. Interstitial inflammation was present in 18 specimens (82%), peritubular capillaritis in 14 (64%), interstitial fibrosis (ci) and tubular atrophy (ct) in 4 (18%), and C4d deposition in the peritubular capillary was present in 6 specimens (27%). Glomerulitis and intimal arteritis were not observed. There was no renal graft loss during the observation period, but deterioration of renal allograft function after biopsy occurred in 9 patients (45%). <b><i>Conclusions:</i></b> In BC, tubulitis and interstitial inflammation were the main constituents. Because glomerulitis was not observed in our study, we suspect that BC contributes to acute T-cell-mediated rejection. Although BC did not lead to renal graft loss, renal graft function deterioration was seen in nearly half of the patients after the renal graft biopsy. We conclude that BC is important clinically and pathologically and needs to be monitored and treated appropriately.


2012 ◽  
Vol 302 (11) ◽  
pp. F1455-F1464 ◽  
Author(s):  
Gina M. Warner ◽  
Jingfei Cheng ◽  
Bruce E. Knudsen ◽  
Catherine E. Gray ◽  
Ansgar Deibel ◽  
...  

Although the two-kidney, one-clip (2K1C) model is widely used as a model of human renovascular hypertension, mechanisms leading to the development of fibrosis and atrophy in the cuffed kidney and compensatory hyperplasia in the contralateral kidney have not been defined. Based on the well-established role of the transforming growth factor (TGF)-β signaling pathway in renal fibrosis, we tested the hypothesis that abrogation of TGF-β/Smad3 signaling would prevent fibrosis in the cuffed kidney. Renal artery stenosis (RAS) was established in mice with a targeted disruption of exon 2 of the Smad3 gene (Smad3 KO) and wild-type (WT) controls by placement of a polytetrafluoroethylene cuff on the right renal artery. Serial pulse-wave Doppler ultrasound assessments verified that blood flow through the cuffed renal artery was decreased to a similar extent in Smad3 KO and WT mice. Two weeks after surgery, systolic blood pressure and plasma renin activity were significantly elevated in both the Smad3 KO and WT mice. The cuffed kidney of WT mice developed renal atrophy (50% reduction in weight after 6 wk, P < 0.0001), which was associated with the development of interstitial fibrosis, tubular atrophy, and interstitial inflammation. Remarkably, despite a similar reduction of renal blood flow, the cuffed kidney of the Smad3 KO mice showed minimal atrophy (9% reduction in weight, P = not significant), with no significant histopathological alterations (interstitial fibrosis, tubular atrophy, and interstitial inflammation). We conclude that abrogation of TGF-β/Smad3 signaling confers protection against the development of fibrosis and atrophy in RAS.


2021 ◽  
pp. 239936932110319
Author(s):  
Yihe Yang ◽  
Zachary Kozel ◽  
Purva Sharma ◽  
Oksana Yaskiv ◽  
Jose Torres ◽  
...  

Introduction: The prevalence of chronic kidney disease (CKD) is high among kidney neoplasm patients because of the overlapping risk factors. Our purpose is to identify kidney cancer survivors with higher CKD risk. Methods: We studied a retrospective cohort of 361 kidney tumor patients with partial or radical nephrectomy. Linear mixed model was performed. Results: Of patients with follow-up >3 months, 84% were identified retrospectively to fulfill criteria for CKD diagnosis, although CKD was documented in only 15%. Urinalysis was performed in 205 (57%) patients at the time of nephrectomy. Multivariate analysis showed interstitial fibrosis and tubular atrophy (IFTA) >25% ( p = 0.005), severe arteriolar sclerosis ( p = 0.013), female gender ( p = 0.024), older age ( p = 0.012), BMI ⩾ 25 kg/m2 ( p < 0.001), documented CKD ( p < 0.001), baseline eGFR ⩽ 60 ml/min/1.73 m2 ( p < 0.001), and radical nephrectomy ( p < 0.001) were independent risk factors of lower eGFR at baseline and during follow-up. Average eGFR decreased within 3 months post nephrectomy. However, patients with different risk levels showed different eGFR time trend pattern at longer follow-ups. Multivariate analysis of time × risk factor interaction showed BMI, radical nephrectomy and baseline eGFR had time-dependent impact. BMI ⩾ 25 kg/m2 and radical nephrectomy were associated with steeper eGFR decrease slope. In baseline eGFR > 90 ml/min/1.73 m2 group, eGFR rebounded to pre-nephrectomy levels during extended follow-up. In partial nephrectomy patients with baseline eGFR ⩾ 90 ml/min/1.73 m2 ( n = 61), proteinuria ( p < 0.001) and BMI ( p < 0.001) were independent risk factors of decreased eGFR during follow up. Conclusions: As have been suggested by others and confirmed by our study, proteinuria and CKD are greatly under-recognized. Although self-evident as a minimum workup for nephrectomy patients to include SCr, eGFR, urinalysis, and proteinuria, the need for uniform applications of this practice should be reinforced. Non-neoplastic histology evaluation is valuable and should include an estimate of global sclerosis% (GS) and IFTA%. Patients with any proteinuria and/or eGFR ⩽ 60 at the time of nephrectomy or in follow-up with urologists, and/or >25% GS or IFTA, should be referred for early nephrology consultation.


2013 ◽  
Vol 304 (7) ◽  
pp. C591-C603 ◽  
Author(s):  
Gabriela Campanholle ◽  
Giovanni Ligresti ◽  
Sina A. Gharib ◽  
Jeremy S. Duffield

Chronic kidney disease, defined as loss of kidney function for more than three months, is characterized pathologically by glomerulosclerosis, interstitial fibrosis, tubular atrophy, peritubular capillary rarefaction, and inflammation. Recent studies have identified a previously poorly appreciated, yet extensive population of mesenchymal cells, called either pericytes when attached to peritubular capillaries or resident fibroblasts when embedded in matrix, as the progenitors of scar-forming cells known as myofibroblasts. In response to sustained kidney injury, pericytes detach from the vasculature and differentiate into myofibroblasts, a process not only causing fibrosis, but also directly contributing to capillary rarefaction and inflammation. The interrelationship of these three detrimental processes makes myofibroblasts and their pericyte progenitors an attractive target in chronic kidney disease. In this review, we describe current understanding of the mechanisms of pericyte-to-myofibroblast differentiation during chronic kidney disease, draw parallels with disease processes in the glomerulus, and highlight promising new therapeutic strategies that target pericytes or myofibroblasts. In addition, we describe the critical paracrine roles of epithelial, endothelial, and innate immune cells in the fibrogenic process.


2010 ◽  
Vol 90 (4) ◽  
pp. 394-400 ◽  
Author(s):  
Julie Ho ◽  
David N. Rush ◽  
Ian W. Gibson ◽  
Martin Karpinski ◽  
Leroy Storsley ◽  
...  

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