Tom Florian Ulmer

Elevated levels of circulating osteopontin are associated with a poor survival after resection of cholangiocarcinoma

BACKGROUND & AIMS Cholangiocarcinoma (CCA) represents a primary hepatic malignancy with incidence and mortality rising globally. Surgical treatment has remained the only potentially curative treatment option, but it is still unclear which patients benefit most from extended liver surgery, highlighting the need for new pre-operative stratification strategies. Osteopontin is a secreted extracellular glyco-phosphoprotein that has been associated with inflammation, metabolic disorders and cancer. Here, we examined the potential of circulating osteopontin serum levels as a diagnostic or prognostic biomarker in patients with CCA undergoing extended liver surgery. METHODS Osteopontin expression levels were analysed in human and murine CCA tumour samples, using semi-quantitative reverse transcriptase PCR and immunohistochemistry. Osteopontin serum concentrations were measured by enzyme-linked immunosorbent assay in 107 patients with CCA undergoing elective tumour resection as well as 55 healthy controls. Results were correlated with clinical data. RESULTS Correlating with an upregulation in CCA tumour cells and the tumour stroma, serum levels of osteopontin were elevated in patients with cholangiocarcinoma compared to healthy controls and patients with primary sclerosing cholangitis. Importantly, pre- and postoperative elevations of osteopontin showed a striking association with poor postoperative survival. CONCLUSIONS Serum osteopontin concentrations represent a promising prognostic biomarker in patients resectable CCA which could help to guide preoperative treatment decisions and to identify patients that will particularly benefit from extended liver surgery. Lay summary: Extended liver surgery is the only potentially curative treatment for patients with cholangiocarcinoma (CCA/biliary cancer), but it is currently unclear which patients benefit most from surgery. Detecting serum levels of osteopontin - a specific secreted glycoprotein involved in multiple human diseases - in CCA patients might help to identify those patients that particularly benefit from tumour resection.

Etiology of Appendicitis in Children: The Role of Bacterial and Viral Pathogens

ABSTRACT Background: Although acute appendicitis is the most common cause for abdominal surgery in children, its etiology is still largely unknown. The aim of this study was to evaluate the role of bacterial and viral pathogens for the etiology of appendicitis in children. Methods: Between 2000 and 2010, 277 children underwent appendectomy in our institution. On this collective, a retrospective study was performed on to identify the presence of bacterial or viral pathogens. Results: Intraoperatively, 39% of cases showed acute, 9% of cases chronic, and 41% of cases ulcerous inflammation. Bowel perforation was found in 7% of cases and four percent of the children had no inflammation of the appendix at all. Escherichia coli was the predominant bacterium with an incidence of 27.4%, followed by streptococci (9.8%). Concerning viral pathogens, adenovirus was the most common with an incidence of 5.4% followed by rotavirus (4.7%). Significant correlations between histopathological findings and present pathogens were found: in cases of bowel perforation there were significantly more infections with E. coli bacteria (32.2%, p < .001), streptococci (12.2%, p < 0.001), and Pseudomonas aeruginosa (6.7%, p < .001) whereas chronic inflammations were accompanied with a significantly elevated rate of yersinia infections (2.5%, p = .016). Acute inflammations were significantly more often associated with campylobacter (1.7%, p = .011) and oxyures infections (6.1%, p < .001). In relation to the patients’ age, a significant accumulation of different pathogens was observed. CRP- and leukocyte counts showed differences between viral and bacterial inflammations. Conclusions: Our data indicates that appendicitis in children might be triggered by bacterial and viral pathogens and that the type of pathogen directly correlates with patient age, type of inflammation, and level of inflammation values. To confirm and further evaluate these findings, additional studies need to be conducted.

CEA but not CA19-9 is an independent prognostic factor in patients undergoing resection of cholangiocarcinoma

Cholangiocarcinoma (CCA) represents a rare form of primary liver cancer with increasing incidence but dismal prognosis. Surgical treatment has remained the only potentially curative treatment option, but it remains unclear which patients benefit most from liver surgery, highlighting the need for new preoperative stratification strategies. In clinical routine, CA19-9 represents the most widely used tumor marker in CCA patients. However, data on the prognostic value of CA19-9 in CCA patients are limited and often inconclusive, mostly due to small cohort sizes. Here, we investigated the prognostic value of CA19-9 in comparison with other standard laboratory markers in a large cohort of CCA patients that underwent tumor resection. Of note, while CA19-9 and CEA were able to discriminate between CCA and healthy controls, CEA showed a higher accuracy for the differentiation between CCA and patients with primary sclerosing cholangitis (PSC) compared to CA19-9. Furthermore, patients with elevated levels of C-reactive protein (CRP), CA19-9 or CEA showed a significantly impaired survival in Kaplan-Meier curve analysis, but surprisingly, only CEA but not CA19-9 represented an independent predictor of survival in multivariate Cox-regression analysis. Our data suggest that CEA might help to identify CCA patients with an unfavourable prognosis after tumor resection.

Colonic wall changes in patients with diverticular disease – Is there a predisposition for a complicated course?

BACKGROUND The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ). METHODS Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ. RESULTS Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values. CONCLUSIONS This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

Hypothermic oxygenated machine perfusion (HOPE) for orthotopic liver transplantation of human liver allografts from extended criteria donors (ECD) in donation after brain death (DBD): a prospective multicentre randomised controlled trial (HOPE ECD-DBD)

Introduction Orthotopic liver transplantation (OLT) has emerged as the mainstay of treatment for end-stage liver disease. In an attempt to improve the availability of donor allografts and reduce waiting list mortality, graft acceptance criteria were extended increasingly over the decades. The use of extended criteria donor (ECD) allografts is associated with a higher incidence of primary graft non-function and/or delayed graft function. As such, several strategies have been developed aiming at reconditioning poor quality ECD liver allografts. Hypothermic oxygenated machine perfusion (HOPE) has been successfully tested in preclinical experiments and in few clinical series of donation after cardiac death OLT. Methods and analysis HOPE ECD-DBD is an investigator-initiated, open-label, phase-II, prospective multicentre randomised controlled trial on the effects of HOPE on ECD allografts in donation after brain death (DBD) OLT. Human whole organ liver grafts will be submitted to 1–2 hours of HOPE (n=23) via the portal vein before implantation and are going to be compared with a control group (n=23) of patients transplanted after conventional cold storage. Primary (peak and Δ peak alanine aminotransferase within 7 days) and secondary (aspartate aminotransferase, bilirubin and international normalised ratio, postoperative complications, early allograft dysfunction, duration of hospital and intensive care unit stay, 1-year patient and graft survival) endpoints will be analysed within a 12-month follow-up. Extent of ischaemia–reperfusion (I/R) injury will be assessed using liver tissue, perfusate, bile and serum samples taken during the perioperative phase of OLT. Ethics and dissemination The study was approved by the institutional review board of the RWTH Aachen University, Aachen, Germany (EK 049/17). The current paper represent the pre-results phase. First results are expected in 2018. Trial registration number NCT03124641.

Allocation procedure has no impact on patient and graft outcome after liver transplantation

The aim of our study was to compare the postoperative outcome after liver transplantation (LT) in patients who received a donor liver via standard or rescue allocation (RA). Special emphasize was laid on the effect extended donor criteria might have on the outcome. One hundred and ten LTs have been performed at the University Hospital Aachen, Germany. A total of 49 patients were included in the standard allocation (SA) group and 53 patients in the RA group. The outcome of LT in both groups was evaluated by the length of stay on the intensive care unit (ICU), duration of hospitalization, 1‐year patient survival, 1‐year graft survival, incidence of primary nonfunction and major complications. Patients in group RA had a significant shorter ICU and overall hospital stay. The 1‐year graft survival was 87.8% in group SA and 88.7% in group RA. The 1‐year patient survival was 87.9% in group SA and 96.2% in group RA. The number of re‐LT was 2% in group SA and 7.5% in group RA. Organs that were rejected for transplantation several times can successfully be transplanted through the RA procedure, thereby enlarging the donor pool without negative effects on the quality of LT.

Expression of VEGFR-2 during Liver Regeneration after Partial Hepatectomy in a Bioluminescence Mouse Model.

Background: Liver regeneration requires the formation of new blood vessels. Endothelial cell proliferation is stimulated by vascular endothelial growth factor (VEGF) and its receptor tyrosine kinase VEGFR-2. The aim of this study was to investigate VEGFR-2 expression in vivo during liver regeneration after partial hepatectomy (PHx). Methods: Transgenic VEGFR-2-luc mice were used in which the luciferase reporter gene was under control of the VEGFR-2 promoter. Following 2/3 PHx, the mice underwent in vivo bioluminescence imaging until the 14th postoperative day. Additionally, liver tissue was analyzed by immunohistochemistry, in vitro luminescence assays, and quantitative RT-PCR. Results: In vivo bioluminescence imaging showed a significant increase in VEGFR-2 promoter activity after PHx. Maximum signal was recorded on the 3rd day; 8 days postoperatively the signal intensity decreased significantly. On the 14th day, bioluminescence signal reached almost baseline levels. Immunohistochemistry, quantitative RT-PCR, and in vitro luminescence confirmed a significant increase on the 3rd day following resection. The mRNA expression of VEGFR-2 was significantly higher on day 3 than preoperatively as well as on day 8. Conclusion: In vivo bioluminescence imaging with transgenic VEGFR-2-luc mice is feasible and provides a convenient model for noninvasively studying VEGFR-2 expression during liver regeneration. This may facilitate further experiments with modulation of angiogenesis by different substances.

Grade of donor liver microvesicular steatosis does not affect the postoperative outcome after liver transplantation

BACKGROUND The potential effect of graft steatosis on the postoperative liver function is discussed controversially. The present study aimed to evaluate the effect of the donor liver microvesicular steatosis on the postoperative outcome after liver transplantation. METHODS Ninety-four patients undergoing liver transplantation at the University Hospital Aachen were included in this study. The patient cohort was divided into three groups according to the grade of microvesicular steatosis (MiS): MiS <30% (n=27), MiS 30%-60% (n=41) and MiS >60% (n=26). The outcomes after liver transplantation were evaluated, including the 30-day and 1-year patient and graft survival rates and the incidences of early allograft dysfunction (EAD) and primary nonfunction (PNF). RESULTS The incidences of EAD and PNF did not differ significantly between the groups. We observed 5 cases of PNF, one occurred in the MiS <30% group and 4 in the MiS 30%-60% group. The 30-day and 1-year graft survivals did not differ significantly between groups. The 30-day patient survival rates were 100% in all groups. The 1-year patient survival rates were 94.4% in the MiS <30% group, 87.9% in the MiS 30%-60% group and 90.9% in the MiS >60% group. CONCLUSION Microvesicular steatosis of donor livers has no negative effect on the postoperative outcome after liver transplantation.

Serum levels of soluble urokinase plasminogen activator receptor (suPAR) predict outcome after resection of colorectal liver metastases

Background In colorectal cancer (CRC), the liver is the most common site of metastasis. Surgical resection represents the standard therapy for patients with colorectal liver metastases (CRLM). However, 5-year survival rates after resection do not exceed 50%, and despite existing preoperative stratification algorithms it is still debated which patients benefit most from surgical treatment. The soluble urokinase plasminogen activator receptor (suPAR) has recently evolved as a promising biomarker for distinct clinical conditions. Here, we examined a potential role of suPAR as a biomarker in patients undergoing resection of CRLM. Results Correlating with upregulated uPAR tissue expression in resected metastases, serum concentrations of suPAR were significantly elevated in CRLM patients compared to healthy controls. Importantly, patients with preoperative suPAR serum levels above the identified ideal cut-off value of 4.83 ng/ml showed a significantly reduced overall survival after resection of CRLM, both in right- and left-sided primary CRC. Moreover, multivariate Cox regression analysis revealed preoperative suPAR serum levels as a prognostic factor for mortality. Additionally, elevated preoperative suPAR but not creatinine levels were a predictor of acute kidney injury (AKI) after CRLM resection, correlating with a longer postoperative hospitalization. Conclusion SuPAR represents a promising novel biomarker in CRLM patients that might help to guide preoperative treatment decisions regarding patients’ outcome and to identify patients particularly susceptible to AKI. Methods Expression levels of uPAR were analyzed in CRLM tissue using RT-PCR and immunohistochemistry. SuPAR serum levels were measured by ELISA in 104 CRC patients undergoing hepatic resection for CRLM and 50 healthy controls.

Influence of Telomere Length in Hepatocytes on Liver Regeneration after Partial Hepatectomy in Rats

Background: The aim of this study was to investigate telomere length in hepatocytes as a biomarker for liver regeneration after partial hepatectomy (PH) in rats. Materials and Methods: Sixty male Wistar rats underwent a 70% PH. One-month-old rats were assigned to group Y (n = 30) and 4-month-old rats were assigned to group O (n = 30). The rats were euthanized, and their livers were then harvested at postoperative day (POD) 1, 2, 3, 4, or 7. Telomere lengths and established parameters for liver regeneration (residual liver weight and levels of proliferating cell nuclear antigen [PCNA], Ki67, and interleukin [IL]-6) were measured. Results: We observed a significant increase in residual liver weight in group Y compared to that in group O (p = 0.001). The levels of Ki67 (p = 0.016), PCNA (p < 0.0001), and IL-6 (p < 0.001) were significantly higher in group Y. Furthermore, the rats in group Y had significantly earlier peak values of Ki67 and PCNA. Telomeres were significantly longer at the time of PH in group Y (p = 0.001). We showed a correlation between telomere length at the day of PH and liver regeneration. Animals with longer telomeres at the time of PH had better liver regeneration (p = 0.015). In group Y, animals with increased liver regeneration (median cut-off: > 122%) did not show any significant difference in telomere length (p = 0.587) compared to rats with regular regeneration (< 122%). However, in the older animals, rats with increased regeneration had significantly longer telomeres (p = 0.019) than rats with regular regeneration. Conclusion: Telomere length in rat hepatocytes depends on age, and animals with long telomeres had earlier and better regeneration of healthy liver tissue than rats with short telomeres. Our data confirms that telomere length in rat hepatocytes could be used as a possible predictive marker for liver regeneration, and could help to identify older individuals with a high capacity for hepatic regeneration.