scholarly journals The role of the gut microbiome in graft fibrosis after pediatric liver transplantation

2020 ◽  
Author(s):  
Tian Qin ◽  
Jingyuan Fu ◽  
Henkjan J. Verkade

Abstract Liver transplantation (LT) is a life-saving option for children with end-stage liver disease. However, about 50% of patients develop graft fibrosis in 1 year after LT, with normal liver function. Graft fibrosis may progress to cirrhosis, resulting in graft dysfunction and ultimately the need for re-transplantation. Previous studies have identified various risk factors for the post-LT fibrogenesis, however, to date, neither of the factors seems to fully explain the cause of graft fibrosis. Recently, evidence has accumulated on the important role of the gut microbiome in outcomes after solid organ transplantation. As an altered microbiome is present in pediatric patients with end-stage liver diseases, we hypothesize that the persisting alterations in microbial composition or function contribute to the development of graft fibrosis, for example by bacteria translocation due to increased intestinal permeability, imbalanced bile acids metabolism, and/or decreased production of short-chain fatty acids (SCFAs). Subsequently, an immune response can be activated in the graft, together with the stimulation of fibrogenesis. Here we review current knowledge about the potential mechanisms by which alterations in microbial composition or function may lead to graft fibrosis in pediatric LT and we provide prospective views on the efficacy of gut microbiome manipulation as a therapeutic target to alleviate the graft fibrosis and to improve long-term survival after LT.

Author(s):  
A. V. Shabunin ◽  
S. P. Loginov ◽  
P. A. Drozdov ◽  
I. V. Nesterenko ◽  
D. A. Makeev ◽  
...  

Rationale. To date, liver transplantation is the most effective method of treating end-stage liver failure, and therefore this treatment has become widespread throughout the world. However, due to the improvement in the quality of transplant care and an increase in the long-term survival of patients, the development of concomitant pathology, which often requires medical treatment, is inevitably associated with a higher life expectancy of liver transplant recipients. Thus, in patients who underwent liver transplantation, there is. a significant increase in the incidence of dyslipidemia. However, a long-term immunosuppressive therapy in organ transplant patients can adversely modify the effect of the prescribed drugs, which requires careful monitoring and consideration of drug interactions.Purpose. Using a clinical example to demonstrate the importance of taking drug interactions into account in the treatment of patients after organ transplantation receiving immunosuppressive drugs.Material and methods. In the presented clinical case, a patient after orthotopic liver transplantation performed in 2005 underwent a staged treatment of cicatricial stricture of choledochal anastomosis in the S.P. Botkin City Clinical Hospital. During the following hospitalization, the patient complained of minor muscle pain when walking. At doctor's visit 3 weeks before hospitalization, a local physician prescribed therapy with atorvastatin 10 mg per day due to an increase in blood plasma cholesterol levels. The patient underwent removal of the self-expanding nitinol stent. During the follow-up examination, the patient had no evidence of an impaired bile outflow, however, muscle pain and weakness progressively increased, the rate of diuresis decreased, and in the biochemical analysis of blood there was an abrupt increase in the concentration of creatinine, aspartate aminotransferase, alanine aminotransferase. Atorvastatin was canceled, a diagnosis of acute non-traumatic rhabdomyolysis was established, treatment with hemodialysis and plasma exchange was started on 03/05/2020. The last session of renal replacement therapy was 03/30/20.Results. With the restoration of the diuresis rate, there was a spontaneous decrease in the level of creatinine to 170 μmol/L. The patient was discharged with satisfactory renal and hepatic function. The pain syndrome completely resolved. Conclusion. Drug interactions between atorvastatin and cyclosporine have resulted in acute rhabdomyolysis with life-threatening consequences. This once again confirms the importance of taking drug interactions into account when managing patients after solid organ transplantation.


Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 600
Author(s):  
Catherine de Magnée ◽  
Louise Brunée ◽  
Roberto Tambucci ◽  
Aurore Pire ◽  
Isabelle Scheers ◽  
...  

Background: ABO-incompatible (ABOi) living donor liver transplantation (LDLT) has been proposed to compensate for donor shortage. To date, few studies have reported detailed ABOi LDLT results in large series of pediatric patients. C4d complement deposition in graft capillaries has been reported to be associated with antibody-mediated rejection in solid organ transplantation. Methods: A retrospective case–control study was conducted, comparing clinical outcomes of each of 34 consecutive pediatric ABOi LDLT recipients with those of 2 non-ABOi pairs (n = 68), matched according to pre-transplant diagnostic criteria, age, and date of transplantation. In addition, we studied the C4d immunostaining pattern in 22 ABOi and in 36 non-ABOi recipients whose liver biopsy was performed within the first 4 post-transplant weeks for suspected acute rejection. Results: The incidence of biliary complications was higher in ABOi recipients (p < 0.05), as were the incidence of acute humoral rejection (p < 0.01) and the incidence of retransplantation (p < 0.05). All children who required retransplantation were older than 1 year at the time of ABOi LDLT. Positive C4d immunostaining was observed in 13/22 (59%) ABOi recipients versus 3/36 (8.3%) non-ABOi recipients (p < 0.0001). Conclusions: ABOi LDLT is a feasible option for pediatric end-stage liver disease but carries increased risks for the recipient, especially for children older than 1 year, even with a specific preparation protocol. C4d immunostaining may be a hallmark of acute humoral rejection in ABOi liver transplantation.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Shasha Xiang ◽  
Kun Ye ◽  
Mian Li ◽  
Jian Ying ◽  
Huanhuan Wang ◽  
...  

Abstract Background Xylitol, a white or transparent polyol or sugar alcohol, is digestible by colonic microorganisms and promotes the proliferation of beneficial bacteria and the production of short-chain fatty acids (SCFAs), but the mechanism underlying these effects remains unknown. We studied mice fed with 0%, 2% (2.17 g/kg/day), or 5% (5.42 g/kg/day) (weight/weight) xylitol in their chow for 3 months. In addition to the in vivo digestion experiments in mice, 3% (weight/volume) (0.27 g/kg/day for a human being) xylitol was added to a colon simulation system (CDMN) for 7 days. We performed 16S rRNA sequencing, beneficial metabolism biomarker quantification, metabolome, and metatranscriptome analyses to investigate the prebiotic mechanism of xylitol. The representative bacteria related to xylitol digestion were selected for single cultivation and co-culture of two and three bacteria to explore the microbial digestion and utilization of xylitol in media with glucose, xylitol, mixed carbon sources, or no-carbon sources. Besides, the mechanisms underlying the shift in the microbial composition and SCFAs were explored in molecular contexts. Results In both in vivo and in vitro experiments, we found that xylitol did not significantly influence the structure of the gut microbiome. However, it increased all SCFAs, especially propionate in the lumen and butyrate in the mucosa, with a shift in its corresponding bacteria in vitro. Cross-feeding, a relationship in which one organism consumes metabolites excreted by the other, was observed among Lactobacillus reuteri, Bacteroides fragilis, and Escherichia coli in the utilization of xylitol. At the molecular level, we revealed that xylitol dehydrogenase (EC 1.1.1.14), xylulokinase (EC 2.7.1.17), and xylulose phosphate isomerase (EC 5.1.3.1) were key enzymes in xylitol metabolism and were present in Bacteroides and Lachnospiraceae. Therefore, they are considered keystone bacteria in xylitol digestion. Also, xylitol affected the metabolic pathway of propionate, significantly promoting the transcription of phosphate acetyltransferase (EC 2.3.1.8) in Bifidobacterium and increasing the production of propionate. Conclusions Our results revealed that those key enzymes for xylitol digestion from different bacteria can together support the growth of micro-ecology, but they also enhanced the concentration of propionate, which lowered pH to restrict relative amounts of Escherichia and Staphylococcus. Based on the cross-feeding and competition among those bacteria, xylitol can dynamically balance proportions of the gut microbiome to promote enzymes related to xylitol metabolism and SCFAs.


2021 ◽  
Vol 22 (13) ◽  
pp. 6975
Author(s):  
Burcin Özdirik ◽  
Tobias Müller ◽  
Alexander Wree ◽  
Frank Tacke ◽  
Michael Sigal

Primary sclerosing cholangitis (PSC) is an immune-related cholangiopathy characterized by biliary inflammation, cholestasis, and multifocal bile duct strictures. It is associated with high rates of progression to end-stage liver disease as well as a significant risk of cholangiocarcinoma (CCA), gallbladder cancer, and colorectal carcinoma. Currently, no effective medical treatment with an impact on the overall survival is available, and liver transplantation is the only curative treatment option. Emerging evidence indicates that gut microbiota is associated with disease pathogenesis. Several studies analyzing fecal and mucosal samples demonstrate a distinct gut microbiome in individuals with PSC compared to healthy controls and individuals with inflammatory bowel disease (IBD) without PSC. Experimental mouse and observational human data suggest that a diverse set of microbial functions may be relevant, including microbial metabolites and bacterial processing of pharmacological agents, bile acids, or dietary compounds, altogether driving the intrahepatic inflammation. Despite critical progress in this field over the past years, further functional characterization of the role of the microbiota in PSC and related malignancies is needed. In this review, we discuss the available data on the role of the gut microbiome and elucidate important insights into underlying pathogenic mechanisms and possible microbe-altering interventions.


2021 ◽  
Vol 22 (3) ◽  
pp. e93-e104
Author(s):  
Rosario Mazzola ◽  
Francesco Cuccia ◽  
Alessandro Bertani ◽  
Slavisa Tubin ◽  
Pier Giulio Conaldi ◽  
...  

2015 ◽  
Author(s):  
Andreea M. Catana ◽  
Michael P. Curry

The first liver transplantation (LT) was performed in 1963, and currently more than 65,000 people in the United States are living with a transplanted liver. In 2012, the number of adults who registered on the LT waiting list decreased for the first time since 2002; 10,143 candidates were added compared with 10,359 in 2011. LT offers long-term survival for complications of end-stage liver disease and prolongs life in properly selected patients, but problems such as donor deficit, geographic disparities, and long waiting lists remain. This overview of LT for the gastroenterologist details the indications for LT and patient selection, evaluation, liver organ allocation, prioritization for transplantation, transplantation benefit by the Model for End-Stage Liver Disease (MELD), MELD limitations, sources of liver graft, strategies employed to decrease the donor deficit, complications, and outcomes. Figures include indications for LT in Europe and the United States, Organ Procurement and Transplantation Network regions in the United States, the number of transplants and size of active waiting lists, mortality by MELD, regional disparity, patient survival rates with and without hepatitis C virus, and unadjusted patient and graft survival. Tables list LT milestones, indications for LT, contraindications for LT, minimal listing criteria for LT, criteria for LT in acute liver failure, LT evaluation process, adult recipient listing status 1A, and early posttransplantation complications. This review contains 7 highly rendered figures, 8 tables, and 46 references. 


2004 ◽  
Vol 286 (6) ◽  
pp. L1129-L1139 ◽  
Author(s):  
Tina L. Sumpter ◽  
David S. Wilkes

Lung transplantation is the only definitive treatment modality for many forms of end-stage lung disease. However, the lung is rejected more often than any other type of solid organ allograft due to chronic rejection known as bronchiolitis obliterans (BO). Indeed, BO is the primary reason why the 5- and 7-yr survival rates are worse for the lung than for any other transplanted organ. Alloimmunity to donor antigens is established as the primary mechanism that mediates rejection responses. However, newer immunosuppressive regimens designed to abrogate alloimmune activation have not improved survival. Therefore, these data suggest that other antigens, unrelated to donor transplantation antigens, are involved in rejection. Utilizing human and rodent studies of lung transplantation, our laboratory has documented that a native collagen, type V collagen [col(V)], is a target of the rejection response. Col(V) is highly conserved; therefore, these data indicate that transplant rejection involves both alloimmune and autoimmune responses. The role of col(V) in lung transplant rejection is described in this review article. In addition, the potential role of regulatory T cells that are crucial to modulating autoimmunity and alloimmunity is also discussed.


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