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Aim: Cellular CD81 is a well characterized hepatitis C virus (HCV) entry factor, while the relevance of soluble exosomal CD81 in HCV pathogenesis is poorly defined. We performed a case-control study to investigate whether soluble CD81 in the exosomal serum fraction is associated with HCV replication and inflammatory activity.
Patients and Methods: Four cohorts were investigated, patients with chronic hepatitis C (n = 37), patients with chronic HCV infection and persistently normal ALT levels (n = 24), patients with long term sustained virologic response (SVR, n = 7), and healthy volunteers (n = 23). Concentration of soluble CD81 was assessed semi-quantitatively after differential centrifugation ranging from 200 g to 100,000 g in the fifth centrifugation fraction by immunoblotting and densitometry.
Results: Soluble CD81 was increased in patients with chronic hepatitis C compared to healthy subjects (p = 0.03) and cured patients (p = 0.017). Patients with chronic HCV infection and persistently normal ALT levels and patients with long term SVR had similar soluble CD81 levels as healthy controls (p>0.2). Overall, soluble CD81 levels were associated with ALT levels (r = 0.334, p = 0.016) and severe liver fibrosis (p = 0.027).
Conclusion: CD81 is increased in the exosomal serum fraction in patients with chronic hepatitis C and appears to be associated with inflammatory activity and severity of fibrosis.
Eosinophilic cholangitis is a potentially underdiagnosed etiology in indeterminate biliary stricture
(2017)
AIM: To investigate presence and extent of eosinophilic cholangitis (EC) as well as IgG4-related disease in patients with indeterminate biliary stricture (IBS).
METHODS: All patients with diagnosis of sclerosing cholangitis (SC) and histopathological samples such as biopsies or surgical specimens at University Hospital Frankfurt from 2005-2015 were included. Histopathological diagnoses as well as further clinical course were reviewed. Tissue samples of patients without definite diagnosis after complete diagnostic work-up were reviewed regarding presence of eosinophilic infiltration and IgG4 positive plasma cells. Eosinophilic infiltration was as well assessed in a control group of liver transplant donors and patients with primary sclerosing cholangitis.
RESULTS: one hundred and thirty-five patients with SC were included. In 10/135 (13.5%) patients, no potential cause of IBS could be identified after complete diagnostic work-up and further clinical course. After histopathological review, a post-hoc diagnosis of EC was established in three patients resulting in a prevalence of 2.2% (3/135) of all patients with SC as well as 30% (3/10) of patients, where no cause of IBS was identified. 2/3 patients with post-hoc diagnosis of EC underwent surgical resection with suspicion for malignancy. Diagnosis of IgG4-related cholangitis was observed in 7/135 patients (5.1%), whereas 3 cases were discovered in post-hoc analysis. 6/7 cases with IgG4-related cholangitis (85.7%) presented with eosinophilic infiltration in addition to IgG4 positive plasma cells. There was no patient with eosinophilic infiltration in the control group of liver transplant donors (n = 27) and patients with primary sclerosing cholangitis (n = 14).
CONCLUSION: EC is an underdiagnosed benign etiology of SC and IBS, which has to be considered in differential diagnosis of IBS.
Genetic heterogeneity of primary lesion and metastasis in small intestine neuroendocrine tumors
(2018)
Data on intratumoral heterogeneity of small intestine neuroendocrine tumors (SI-NETs) and related liver metastasis are limited. The aim of this study was to characterize genetic heterogeneity of 5 patients with SI-NETs. Therefore, formalin-fixed, paraffin-embedded tissue samples of primary and metastatic lesions as well as benign liver of five patients with synchronously metastasized, well differentiated SI-NETs were analyzed with whole exome sequencing. For one patient, chip based 850k whole DNA methylome analysis was performed of primary and metastatic tumor tissue as well as control tissue. Thereby, 156 single nucleotide variants (SNVs) in 150 genes were identified and amount of mutations per sample ranged from 9–34 (mean 22). The degree of common (0–94%) and private mutations per sample was strongly varying (6–100%). In all patients, copy number variations (CNV) were found and the degree of intratumoral heterogeneity of CNVs corresponded to SNV analysis. DNA methylation analysis of a patient without common SNVs revealed a large overlap of common methylated CpG sites. In conclusion, SI-NET primary and metastatic lesions show a highly varying degree of intratumoral heterogeneity. Driver events might not be detectable with exome analysis only, and further comprehensive studies including whole genome and epigenetic analyses are warranted.
Background: Definite diagnosis and therapeutic management of cholangiocarcinoma (CCA) remains a challenge. The aim of the current study was to investigate feasibility and potential impact on clinical management of targeted sequencing of intraductal biopsies.
Methods: Intraductal biopsies with suspicious findings from 16 patients with CCA in later clinical course were analyzed with targeted sequencing including tumor and control benign tissue (n = 55 samples). A CCA-specific sequencing panel containing 41 genes was designed and a dual strand targeted enrichment was applied.
Results: Sequencing was successfully performed for all samples. In total, 79 mutations were identified and a mean of 1.7 mutations per tumor sample (range 0–4) as well as 2.3 per biopsy (0–6) were detected and potentially therapeutically relevant genes were identified in 6/16 cases. In 14/18 (78%) biopsies with dysplasia or inconclusive findings at least one mutation was detected. The majority of mutations were found in both surgical specimen and biopsy (68%), while 28% were only present in biopsies in contrast to 4% being only present in the surgical tumor specimen.
Conclusion: Targeted sequencing from intraductal biopsies is feasible and potentially improves the diagnostic yield. A profound genetic heterogeneity in biliary dysplasia needs to be considered in clinical management and warrants further investigation.
Translational impact: The current study is the first to demonstrate the feasibility of sequencing of intraductal biopsies which holds the potential to impact diagnostic and therapeutical management of patients with biliary dysplasia and neoplasia.
Immune-modulating therapy is a promising therapy for patients with cholangiocarcinoma (CCA). Microsatellite instability (MSI) might be a favorable predictor for treatment response, but comprehensive data on the prevalence of MSI in CCA are missing. The aim of the current study was to determine the prevalence of MSI in a German tertiary care hospital. Formalin-fixed paraffin-embedded tissue samples, obtained in the study period from 2007 to 2015 from patients with CCA undergoing surgical resection with curative intention at Johann Wolfgang Goethe University hospital, were examined. All samples were investigated immunohistochemically for the presence of MSI (expression of MLH1, PMS2, MSH2, and MSH6) as well as by pentaplex polymerase chain reaction for five quasimonomorphic mononucleotide repeats (BAT-25, BAT-26, NR-21, NR-22, and NR-24). In total, 102 patients were included, presenting intrahepatic (n = 35, 34.3%), perihilar (n = 42, 41.2%), and distal CCA (n = 25, 24.5%). In the immunohistochemical analysis, no loss of expression of DNA repair enzymes was observed. In the PCR-based analysis, one out of 102 patients was found to be MSI-high and one out of 102 was found to be MSI-low. Thus, MSI seems to appear rarely in CCA in Germany. This should be considered when planning immune-modulating therapy trials for patients with CCA.
Patients after orthopic liver transplantation (OLT) are at risk of developing graft dysfunction. Sphingolipids (SL’s) have been identified to play a pivotal role in the regulation of hepatocellular apoptosis, inflammation and immunity. We aimed to investigate the serum SL profile in a prospective real-world cohort of post-OLT patients. From October 2015 until July 2016, 149 well-characterized post-OLT patients were analyzed. SL’s were assessed in serum probes via Liquid Chromatography/Tandem Mass Spectrometry. Twenty-nine (20%) patients had a biopsy proven graft rejection with decreased C20-ceramide (Cer) (p = 0.042), C18-dihydroceramide (DHC) (p = 0.022) and C24DHC (p = 0.060) levels. Furthermore, C18DHC (p = 0.044) and C24DHC (p = 0.011) were significantly down-regulated in patients with ischemic type biliary lesions (ITBL; n = 15; 10%). One-hundred and thirty-three patients (89%) have so far received tacrolimus as the main immunosuppressive agent with observed elevations of C14Cer (p = 0.052), C18Cer (p = 0.049) and C18:1Cer (p = 0.024). Hepatocellular carcinoma (HCC) pre-OLT was associated with increases in C24:1Cer (p = 0.024) and C24:1DHC (p = 0.024). In this large prospective cross-sectional study of patients, post-OLT serum levels of (very-)long chain (dihydro-)ceramides associate with graft rejection, ITBL, tacrolimus intake and HCC pre-OLT. Hence, serum SL’s may be indicative of graft complications. Further research is necessary to identify their diverse mechanistic role in regulating immunity and inflammation in patients post-OLT.
Background: Computed tomography of the head (HCT) is a widely used diagnostic tool, especially for emergency and trauma patients. However, the diagnostic yield and outcomes of HCT for patients on medical intensive care units (MICUs) are largely unknown.
Methods: We retrospectively evaluated all head CTs from patients admitted to a single-center MICU during a 5-year period for CT indications, diagnostic yield, and therapeutic consequences. Uni- and multivariate analyses for the evaluation of risk factors for positive head CT were conducted.
Results: Six hundred ninety (18.8%) of all patients during a 5-year period underwent HCT; 78.7% had negative CT results, while 21.3% of all patients had at least 1 new pathological finding. The main indication for acquiring CT scan of the head was an altered mental state (AMS) in 23.5%, followed by a new focal neurology in 20.7% and an inadequate wake up after stopping sedation in 14.9% of all patients. The most common new finding was intracerebral bleeding in 6.4%. In 6.7%, the CT scan itself led to a change of therapy of any kind. Admission after resuscitation or a new focal neurology were independent predictors of a positive CT. Psychic alteration and AMS were both independent predictors of a higher chance of a negative head CT. Positive HCT during MICU is an independent predictor of lower survival.
Conclusions: New onset of focal neurologic deficit seems to be a good predictor for a positive CT, while AMS and psychic alterations seem to be very poor predictors. A positive head CT is an independent predictor of death for MICU patients.
Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 23
The measured particle ratios in central heavy-ion collisions at RHIC-BNL are investigated within a chemical and thermal equilibrium chiral SU(3) σ–ω approach. The commonly adopted noninteracting gas calculations yield temperatures close to or above the critical temperature for the chiral phase transition, but without taking into account any interactions. Contrary, the chiral SU(3) model predicts temperature and density dependent effective hadron masses and effective chemical potentials in the medium and a transition to a chirally restored phase at high temperatures or chemical potentials. Three different parametrizations of the model, which show different types of phase transition behaviour, are investigated. We show that if a chiral phase transition occured in those collisions, “freezing” of the relative hadron abundances in the symmetric phase is excluded by the data. Therefore, either very rapid chemical equilibration must occur in the broken phase, or the measured hadron ratios are the outcome of the dynamical symmetry breaking. Furthermore, the extracted chemical freeze-out parameters differ considerably from those obtained in simple noninteracting gas calculations. In particular, the three models yield up to 35 MeV lower temperatures than the free gas approximation. The in-medium masses turn out to differ up to 150 MeV from their vacuum values.
Background and Aim: The main disadvantage of plastic stents is the high rate of stent occlusion. The usual replacement interval of biliary plastic stents is 3 months. This study aimed to investigate if a shorter interval of 6–8 weeks impacts the median premature exchange rate (mPER) in benign and malignant biliary strictures.
Methods: All cases with endoscopic retrograde cholangiopancreatography (ERCP) and plastic stent placement were retrospectively analyzed since establishing an elective replacement interval of every 6–8 weeks at our institution and mPER was determined.
Results: A total of 3979 ERCPs (1199 patients) were analyzed, including 1262 (31.7%) malignant and 2717 (68.3%) benign cases, respectively. The median stent patency (mSP) was 41 days (range 14–120) for scheduled stent exchanges, whereas it was 17 days (1–75) for prematurely exchanged stents. The mPER was significantly higher for malignant (28.1%, 35–50%) compared with benign strictures (15.2%, 10–28%), P < 0.0001, respectively. mSP was significantly shorter in cases with only one stent (34 days [1–87] vs 41 days [1–120]) and in cases with only a 7-Fr stent (28 days [2–79]) compared with a larger stent (34 days [1–87], P = 0.001). Correspondingly, mPER was significantly higher in cases with only one stent (23% vs 16.2%, P < 0.0001) and only a 7-Fr stent (31.3% vs 22.4%, P = 0.03).
Conclusion: A shorter replacement interval does not seem to lead to a clinically meaningful reduction of mPER in benign and malignant strictures. Large stents and multiple stenting should be favored as possible.