Christoph Anthoni

Tissue factor: a mediator of inflammatory cell recruitment, tissue injury, and thrombus formation in experimental colitis.

There is growing evidence for an interplay between inflammatory and coagulation pathways in acute and chronic inflammatory diseases. However, it remains unclear whether components of the coagulation pathway, such as tissue factor (TF), contribute to intestinal inflammation, and whether targeting TF will blunt the inflammatory cell recruitment, tissue injury, and enhanced thrombus formation that occur in experimental colitis. Mice were fed 3% dextran sodium sulfate (DSS) to induce colonic inflammation, with some mice receiving a mouse TF-blocking antibody (muTF-Ab). The adhesion of leukocytes and platelets in colonic venules, light/dye-induced thrombus formation in cremaster muscle microvessels, as well as disease activity index, thrombin–antithrombin (TAT) complexes in plasma, and histopathologic changes in the colonic mucosa were monitored in untreated and muTF-Ab–treated colitic mice. In untreated mice, DSS elicited the recruitment of adherent leukocytes and platelets in colonic venules, caused gross and histologic injury, increased plasma TAT complexes, and enhanced thrombus formation in muscle arterioles. muTF-Ab prevented elevation in TAT complexes, reduced blood cell recruitment and tissue injury, and blunted thrombus formation in DSS colitic mice. These findings implicate TF in intestinal inflammation and support an interaction between inflammation and coagulation in experimental colitis.

Prognostic factors for kidney allograft survival in the Eurotransplant Senior Program.

BACKGROUND The shortage of organ donors has led to the introduction of the Eurotransplant Senior Program (ESP) to optimize the allocation of kidneys from elderly donors by age-matching. In the face of a rapidly aging population, identification of prognostic factors for kidney allograft survival within the ESP population will be of enormous significance. MATERIAL AND METHODS Donor and recipient data from 89 patients transplanted under the ESP protocol between 1999 and 2007 were retrospectively analyzed. Data were correlated with initial graft function, graft survival, acute rejection episodes, serum creatinine levels, glomerular filtration rates, and patient survival using univariate and multivariate analysis. Maximum follow-up was 5 years. RESULTS Cold ischemia time (CIT) >16 hours, body mass index (BMI) ≥25 kg/m(2), and kidney re-transplantation were significant risk factors for delayed graft function (DGF). Odds ratio for primary non-function was significantly increased with prolonged CIT, BMI ≥25 kg/m(2), and duration of renal replacement therapy >69 months. CIT >15 h, DGF, and kidney re-transplantation were associated with poor graft survival (P<0.05). CONCLUSIONS Risk reduction (e.g., aiming at CIT <15 h) and close surveillance of patients at risk appear to be crucial for allograft survival in the ESP.

Tacrolimus Concentration/Dose Ratio is Associated with Renal Function After Liver Transplantation

BACKGROUND The calcineurin inhibitor (CNI) tacrolimus (Tac) is an effective immunosuppressant used after liver transplantation (LTx), but is often associated with CNI nephrotoxicity. Currently, there is no simple clinical predictor for CNI nephrotoxicity after LTx. We hypothesized that the Tac metabolism rate - defined as the blood concentration normalized by its daily dose (the C/D ratio) - is associated with post-LTx renal impairment. MATERIAL AND METHODS We analyzed the relationship between the C/D ratio and post-transplant renal function in 179 patients who underwent LTx between 2000 and 2012 and were initially immunosuppressed with Tac, mycophenolate mofetil, and prednisolone. Six months after LTx, 115 patients were categorized into 1 of 2 groups based on their Tac C/D ratio (<1.09 or ≥1.09): fast (n=58) or slow (n=57) metabolizers. The renal function was determined 36 months after LTx using the estimated glomerular filtration rate (eGFR) as described by Cockcroft and Gault. RESULTS At the time of LTx there was no statistically significant difference between the eGFR of fast and slow metabolizers. Six months (P=0.016), 12 months (P=0.001), and 36 months (P=0.018) after LTx, fast Tac metabolizers had significantly more impaired renal function than slow metabolizers. Because of a presumption of CNI nephrotoxicity, 32.8% of fast metabolizers and 14.0% of slow metabolizers were switched from Tac to other immunosuppressants (P=0.027). CONCLUSIONS In this study, the Tac metabolism rate appears to influence renal function after LTx, suggesting that a C/D ratio of <1.09 is associated with increased CNI nephrotoxicity in LTx recipients.

Challenges in pancreatic adenocarcinoma surgery - National survey and current practice guidelines.

Background Pancreatic ductal adenocarcinoma (PDAC) remains one of the most deadly cancers in Europe and the USA. There is consensus that radical tumor surgery is the only viable option for any long-term survival in patients with PDAC. So far, limited data are available regarding the routine surgical management of patients with advanced PDAC in the light of surgical guidelines. Methods A national survey on perioperative management of patients with PDAC and currently applied criteria on their tumor resectability in German university and community hospitals was carried out. Results With a response rate of 81.6% (231/283) a total of 95 (41.1%) participating departments practicing pancreatic surgery in Germany are certified as competence and reference centers for surgical diseases of the pancreas in 2016. More than 95% of them indicate to carry out structured and interdisciplinary therapies along with an interdisciplinary pre- and postoperative tumor board. The majority of survey respondents prefer the pylorus-preserving partial pancreatoduodenectomy (93.1%) with standard lymphadenectomy for cancer of the pancreatic head. Intraoperative histological evaluation of the resection margins is used regularly by 99% of the survey respondents. 98.7% of survey respondents carry out partial or complete vein resection, 126 respondents (54.5%) would resect tumor adjacent arteries, and 102 respondents (44.2%) would perform metastasectomy if complete PDAC resection (R0) is possible. Conclusion Evidence-based and standardized pancreatic surgery is practiced by a large number of hospitals in Germany. However, a significant number of survey respondents support an extended radical tumor resection in patients with advanced PDAC even when not indicated by current clinical guidelines.

Downregulation of CX3CR1 ameliorates experimental colitis: evidence for CX3CL1-CX3CR1-mediated immune cell recruitment

PurposeInflammatory conditions like inflammatory bowel diseases (IBD) are characterized by increased immune cell infiltration. The chemokine ligand CX3CL1 and its receptor CX3CR1 have been shown to be involved in leukocyte adhesion, transendothelial recruitment, and chemotaxis. Therefore, the objective of this study was to describe CX3CL1-CX3CR1-mediated signaling in the induction of immune cell recruitment during experimental murine colitis.MethodsAcute colitis was induced by dextran sodium sulfate (DSS), and sepsis was induced by injection of lipopolysaccharide (LPS). Serum concentrations of CX3CR1 and CX3CL1 were measured by ELISA. Wild-type and CX3CR1-/- mice were challenged with DSS, and on day 6, intravital microscopy was performed to monitor colonic leukocyte and platelet recruitment. Intestinal inflammation was assessed by disease activity, histopathology, and neutrophil infiltration.ResultsCX3CR1 was upregulated in DSS colitis and LPS-induced sepsis. CX3CR1-/- mice were protected from disease severity and intestinal injury in DSS colitis, and CX3CR1 deficiency resulted in reduced rolling of leukocytes and platelets.ConclusionsIn the present study, we provide evidence for a crucial role of CX3CL1-CX3CR1 in experimental colitis, in particular for intestinal leukocyte recruitment during murine colitis. Our findings suggest that CX3CR1 blockade represents a potential therapeutic strategy for treatment of IBD.

Mo1696 CX3CL1-CX3CR1 in Acute Colitis: Evidence for Chemokine-Mediated Leukocyte Recruitment

The gastrointestinal microbial communities of C57BL/6 mice between Taconic Farms (Tac) and Jackson Laboratory (Jax) are highly variable; most notably, only the Tac mice are colonized with segmented filamentous bacteria (SFB), a potent inducer of proinflammatory TH17 cells. To examine whether Jax and Tac mice have a different intestinal microbiome and respond differently to H. pylori (Hp) infection, C57BL/6 mice from Tac and Jax were dosed with Hp PMSS1. As measured by Illumina sequencing, OTUs in fecal microbiomes were richer in Tac than Jax mice (p<0.01); the ratio of Bacteriodetes to Firmicutes, two predominant phyla, were 1.86 for Jax but 0.33 for Tac mice. In addition, the results obtained by qPCR demonstrated that colonization status of 5 mucosa-associated species ASF356, ASF361, ASF457, ASF500, ASF519 (members of altered schaedler flora) in the stomachs of the control mice from the 2 vendors were comparable, while there were significantly lower levels of ASF457 and ASF519 but higher levels of ASF361 and ASF500 in the ceca of control Jax mice compared to the Tac counterparts (P<0.01). By 16 weeks-post-inoculation, there were significantly lower levels of gastric and cecal ASF361, cecal ASF457, ASF500 and ASF519, but higher levels of cecal ASF356 in the infected Jax mice compared to their controls (P<0.01). Hp infection in Tac mice also increased SFB levels in the large intestine but did not influence ileal SFB levels compared to the controls. In contrast, Hp infection was only associated with higher levels of cecal ASF356 in the infected Tac mice compared to the sham controls (P<0.0001). Interestingly, Hp infection significantly altered fecal microbial compositions of Tac mice with an increase of the class Bacilli and a decrease in the classes Clostridia and Bacteroidia but this was not noted in Jax mice. Hp colonization levels and mRNA expression of gastric Il-1β, Il-17A, and RegIIIγwere significantly lower in Tac compared to Jax mice (P<0.05). In contrast, mRNA levels of gastric Inf-γ, Tnf-α, and Foxp-3 were comparable between the infected Jax and Tac groups. There were no significant differences in gastric pathology including inflammation, epithelial defects, oxyntic atrophy, hyperplasia, and dysplasia between the infected Jax and Tac groups, except for mucus metaplasia that was more severe in the infected Tac mice vs. the infected Jax mice (P<0.05). Our data indicate that the overall gastrointestinal microbiomes in Tac mice are more diverse and prone to Hp perturbation compared to Jax mice, while there is more profound Hp-associated change in colonization levels of the 5 mucosa-associated ASF species in Jax mice than Tac mice. Long-term clinical effects of the different responses in the microbiome and inflammation-associated mediators to Hp infection between Jax and Tac mice needs further study.

Die Rolle von RANTES in der experimentellen murinen Kolitis

Background and Aim: There is a large body of evidence that platelets and chemokines such as RANTES play a major role in the pathogenesis of chronic inflammatory bowel disease (IBD). Since platelets are a rich source of RANTES and circulate in an activated state in patients with IBD the aim of this study was to examine the role and the cellular source of RANTES in the DSS model of intestinal inflammation. Methods: Different strategies against RANTES were used (anti RANTES antibodies, k/o animals and RANTES-/- -WT chimeras). Clinical parameters, histology and intravital microscopy to asses leukocyte/platelet-endothelial interactions and vascular permeability were employed. Results: Tissue damage following DSS was significantly blunted by all Anti RANTES strategies. Also lack of RANTES in all circulating cells (RANTES-/- -WT chimera) confered significant protection. Increased cellular-endothelial adhesion is abrogated and the microvascular permeability is significantly decreased after total or partial ablation of RANTES. Conclusion: Our results clearly show that RANTES plays an important role in the mediation of tissue damage in this model. We are able to demonstrate that vascular permeability and cellular adhesion are regulated by RANTES derived from circulating cells. Our data suggests that RANTES could be a potential target in IBD.