U. Töx

Expression of platelet-derived growth factor-C and insulin-like growth factor I in hepatic stellate cells is inhibited by miR-29

MicroRNAs are short noncoding, endogenous RNA species that posttranscriptionally inhibit gene expression by targeting the untranslated region (UTR) of mRNAs. Recently, it was shown that miR-29 inhibits expression of extracellular matrix proteins such as collagens, suggesting an antifibrotic function of miR-29. In the present study, we now investigated the role of miR-29 in profibrogenic growth factor expression as a further central mechanism of fibrosis. Screening of databases revealed putative miR-29 target sequences in the mRNA of platelet-derived growth factor (PDGF)-B, PDGF-B receptor, PDGF-C, vascular endothelial growth factor-A, and insulin-like growth factor (IGF)-I. To analyze miR-29 interaction with the predicted binding sites, we cloned the 3′-UTR sequences of the putative targets in fusion to the luciferase-reporter coding sequence. Functional miR-29 binding to PDGF-C and IGF-I mRNA sequences, but not to the corresponding mutants, was then proven by reporter assays. Hepatic stellate cells (HSC) that transdifferentiate into myofibroblasts, producing extracellular matrix proteins and profibrogenic growth factors, for example, the members of the PDGF family, are crucial for liver fibrosis. Myofibroblastic transition of primary HSC resulted in the loss of miR-29, but in a significant increase of PDGF-C and IGF-I. Compensation of reduced miR-29 levels by miR-29 overexpression in myofibroblastic HSC was followed by a definitive repression of IGF-I and PDGF-C synthesis. After experimental fibrosis, induced by bile-duct occlusion, miR-29 expression was shown to be reduced, but IGF-I and PDGF-C expression was upregulated, correlating inversely to the miR-29 pattern. Thus, we conclude that miR-29, downregulated during fibrosis, acts as an antifibrogenic mediator not only by targeting collagen biosynthesis, but also by interfering with profibrogenic cell communication via PDGF-C and IGF-I.

β -Adrenoceptor blockade in sclerosing cholangitis of Mdr2 knockout mice: antifibrotic effects in a model of nonsinusoidal fibrosis

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with high propensity to develop into cholangiocarcinoma. The hepatobiliary disorder of PSC is due to progressive fibrosis surrounding the intra- and extrahepatic bile ducts. Until now, no effective medical therapy exists. To study the progression of sclerosing cholangitis after inhibition of the sympathetic nervous system by blockade of the β-adrenoceptors, we used the Mdr2−/− mouse model, which develops periportal fibrosis similar to human PSC. Liver tissues of Mdr2−/− mice untreated or treated with the β-adrenoceptor antagonist propranolol were analyzed for inflammation and fibrosis progression at different time points by histological scoring and immunostaining for α-smooth muscle actin (α-SMA), CD45 and S100A4. Transaminases and hydroxyproline contents were determined. Expression of angiotensinogen, endothelin-1, TGF-β, TNF-α, CTGF and procollagen 1A1 was studied by real-time PCR on laser-microdissected areas of acinar zones I and II–III. After 3 months, periportal fibrosis had developed in Mdr2−/− mice, but immunostaining revealed no sinusoidal and only minor periportal contribution of myofibroblasts with prominent fibroblasts. Propranolol treatment of Mdr2−/− mice improved liver architecture. Additionally, inflammation and fibrosis were significantly reduced. After 3 months of treatment, the antifibrotic effect of the β-blockade was most obvious. The transcript levels of procollagen 1A1, TNF-α, TGF-β, CTGF and endothelin-1 were markedly repressed in the portal areas of treated mice. Taken together, these data show that propranolol efficiently delays progression of sclerosing cholangitis. Therefore, the blockade of β-adrenoceptors is a promising option to support future therapeutic strategies in the treatment of human PSC.

Clostridium Difficile Infection in Patients with Acute Myelogenous Leukemia and in Patients Undergoing Allogeneic Stem Cell Transplantation: Epidemiology and Risk Factor Analysis

Patients receiving treatment for acute myelogenous leukemia (AML) and recipients of allogeneic stem cell transplantation (aSCT) are at high risk of contracting Clostridium difficile infection (CDI), the most frequently observed nosocomial diarrhea and enterocolitis. Data were retrieved from the prospective Cologne Cohort of Neutropenic Patients. Patients hospitalized for aSCT as well as patients receiving treatment for AML were included in the analysis. Risk factor analysis for the occurrence of CDI was performed by backward-stepwise logistic regression (P < .1). During the period from January 2007 to August 2010, 310 hospitalizations of 152 patients with AML and 229 hospitalizations of 223 patients undergoing aSCT were eligible for analysis. Incidence rates for CDI per 10,000 patient days were 17.9 for AML patients and 27.4 for aSCT recipients. Among AML and aSCT patients, median time from initiation of chemotherapy to CDI was 10 days (range, -8 to 101 days) and 17 days (range, 6 to 79), respectively. Logistic regression identified carbapenem exposure to be associated with development of CDI in AML patients (odds ratio [OR], 2.2) and aSCT recipients (OR, 1.4). In both groups, previous exposure to carbapenems was significantly associated with development of CDI. A follow-up study, assessing the effect of an antibiotic stewardship intervention to decrease the administration of carbapenems in hematological high-risk patients, is warranted.

NIKEI: a new inexpensive and non-invasive scoring system to exclude advanced fibrosis in patients with NAFLD.

Aims To develop, validate and compare a non-invasive fibrosis scoring system for non-alcoholic fatty liver disease (NAFLD) derived from routinely obtained clinical and biochemical parameters. Methods 267 consecutive patients with biopsy proven fatty liver or non-alcoholic steatohepatitis were randomly assigned to the estimation (2/3) or validation (1/3) group to develop a model for the prediction of advanced fibrosis. Univariate statistics were performed to compare patients with and without advanced fibrosis, and following a multivariate logistic regression analysis a new scoring system was constructed. This non-invasive Koeln-Essen-index (NIKEI) was validated and compared to the FIB-4 index by calculating the area under the receiver operating characteristic curve (AUC). We evaluated a stepwise combination of both scoring systems for the precise prediction of advanced fibrosis. To set in contrast, we additionally tested the diagnostic accuracy of the AST/ALT ratio, BARD score and the NAFLD fibrosis score in our cohort. Results Age, AST, AST/ALT ratio, and total bilirubin were identified as significant predictors of advanced fibrosis and used to construct the NIKEI with an AUC of 0.968 [0.937; 0.998] compared to 0.929 [0.869; 0.989] for the FIB-4 index. The absence of advanced fibrosis could be confirmed with excellent accuracy (99–100%). The positive predictive value of the FIB-4 index was higher (100% vs. 60%), however, the false negative rate was also high (33%). With a stepwise combination of both indices 82%–84% of biopsies would have been avoidable without a single misclassification. The AUROC for AST/ALT ratio, the NAFLD fibrosis score, and the BARD score were 0.81 (95% CI, 0.72–0.90), 0.96 (95% CI 0.92–0.99), and 0.67 (95% CI 0.55–0.78), respectively. Conclusion The NIKEI can reliably exclude advanced fibrosis in subjects with NAFLD. In combination with the FIB-4 index misclassification with inadequate clinical management can be avoided while the need for liver biopsies can be reduced.

Stepwise combination of simple noninvasive fibrosis scoring systems increases diagnostic accuracy in nonalcoholic fatty liver disease.

Objective: Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease ranging from simple fatty liver to steatohepatitis, fibrosis, and cirrhosis. We aimed to analyze the diagnostic performance and clinical utility of simple noninvasive tests alone or in combination for the detection of advanced fibrosis in patients with NAFLD. Design and Subjects: Data from 323 patients with biopsy-proven NAFLD/NASH who presented to the Clinic for Gastroenterology and Hepatology, University Hospital of Cologne between July 1998 and November 2009, were analyzed retrospectively. Sensitivity, specificity, positive predictive values, and negative predictive values were determined along with the area under receiver operating characteristic curves (AUROC) using published formulas for NAFLD, FIB-4, and BARD fibrosis scores. Results: The area under receiver operating characteristic curves were as follows: NAFLD fibrosis score 0.96 [95% confidence interval (CI), 0.92-0.99], FIB-4 0.95 (95% CI, 0.91-1.00), BARD 0.82 (95% CI, 0.71-0.92) with negative predictive values for advanced fibrosis of 96%, 98%, and 96%, respectively. When applying the NAFLD, FIB-4, or BARD scoring systems 25%, 15%, or 26% of cases with advanced fibrosis would have been missed. Combining FIB-4 and BARD in a stepwise fashion, patients would have been correctly classified without biopsy in 67% of cases without missing a single case of advanced fibrosis. Conclusions: The FIB-4 and NAFLD fibrosis scores perform better than the BARD scoring system. Liver biopsy can securely be replaced only with a stepwise combination of simple noninvasive tests, otherwise the assessment of risk due to advanced fibrosis may be misleading in a clinically meaningful proportion of patients.

Successful treatment of radiofrequency-induced biliary lesions by interventional endoscopic retrograde cholangiography (ERC)

Background: Radiofrequency ablation (RFA) of malignant liver lesions is considered a procedure with low morbidity. However, RFA performed close to hilar structures carries the risk of heat-induced biliary tract damage and subsequent septic episodes. Methods: We performed an analysis of complications in 42 patients with 211 liver lesions treated with a combined approach of liver resection and RFA. Results: One patient died due to postoperative liver failure. There was one case of temporary liver dysfunction, one vena cava thrombosis, and six febrile episodes. Four of the six febrile episodes were related to bile duct injuries. They became evident 3–5 weeks after the procedure. All four patients were treated successfully by the placement of stents within the biliary tract. None of the patients developed a hepatic abscess. Conclusion: Biliary tract damage is a complication that can occur weeks after RFA. Immediate endoscopic intervention can obviate the occurrence of prolonged septic complications.

Salvage Therapy of Refractory Chronic Disseminated Candidiasis in a Patient with Acute Myeloid Leukaemia and Secondary Prophylaxis During Allogeneic Stem Cell Transplantation

We report on the treatment course of a 27‐year‐old male patient with acute myeloid leukaemia M1 and chronic disseminated candidiasis. After induction chemotherapy, the patient developed oesophageal candidiasis while participating in a voriconazole vs. placebo prophylaxis trial. He was then switched to oral fluconazole 400 mg q.i.d. After 6 days of futile fluconazole therapy he was switched to caspofungin 50 mg q.i.d. Caspofungin dose was later increased to 100 mg q.i.d after disseminated candidiasis with involvement of lung, spleen and liver was diagnosed. Following 63 days of caspofungin without resolution of symptoms, i.e. being persistently febrile, and emergence of soft tissue Candida abscesses, he was included into a trial allowing compassionate use of posaconazole as salvage therapy for refractory invasive fungal infections. Symptoms rapidly resolved under posaconazole 200 mg q.i.d. treatment and the patient was able to undergo allogeneic haematopoietic stem cell transplantation on secondary prophylaxis with posaconazole.

[Primary cholangiocarcinoma in a case of Caroli's disease: case report and literature review].

ZusammenfassungDie Caroli-Erkrankung ist eine Lebererkrankung mit segmentaler zystischer Dilatation der intrahepatischen Gallenwege, die zu den angeborenen Duktalplattenmalformationen gezählt wird. Sie ist mit einer Inzidenz von 0,05% bezogen auf alle Fälle des Kölner Leberregisters extrem selten. Sie geht meist mit Cholangitis und Hepatolithiasis einher. Therapeutische Ziele sind die Infektionskontrolle und der Erhalt der biliären Drainage. Als Komplikationen können eine intraepitheliale Neoplasie des auskleidenden Epithels und auch Karzinome entstehen. Wir stellen hier den Fall einer Caroli-Erkrankung mit Entwicklung eines Cholangiokarzinoms vor und diskutieren die Literatur.AbstractCaroli’s disease is a liver disease with segmental cystic dilatation of the intrahepatic bile ducts. It belongs to the group of congenital ductal plate malformations. With an incidence of only 0.05% of all liver cases in the Liver Registry of the University of Cologne, it is a very rare disorder. Caroli’s disease is usually combined with cholangitis and bile duct stones. Control of these infections and maintenance of biliary drainage are the main therapeutic aims. The development of intra epithelial neoplasia and invasive carcinoma are rare complications.We report a case of Caroli’s disease with the development of cholangiocarcinoma and review the literature.

Primäres Cholangiokarzinom auf dem Boden einer Caroli-Erkrankung

ZusammenfassungDie Caroli-Erkrankung ist eine Lebererkrankung mit segmentaler zystischer Dilatation der intrahepatischen Gallenwege, die zu den angeborenen Duktalplattenmalformationen gezählt wird. Sie ist mit einer Inzidenz von 0,05% bezogen auf alle Fälle des Kölner Leberregisters extrem selten. Sie geht meist mit Cholangitis und Hepatolithiasis einher. Therapeutische Ziele sind die Infektionskontrolle und der Erhalt der biliären Drainage. Als Komplikationen können eine intraepitheliale Neoplasie des auskleidenden Epithels und auch Karzinome entstehen. Wir stellen hier den Fall einer Caroli-Erkrankung mit Entwicklung eines Cholangiokarzinoms vor und diskutieren die Literatur.AbstractCaroli’s disease is a liver disease with segmental cystic dilatation of the intrahepatic bile ducts. It belongs to the group of congenital ductal plate malformations. With an incidence of only 0.05% of all liver cases in the Liver Registry of the University of Cologne, it is a very rare disorder. Caroli’s disease is usually combined with cholangitis and bile duct stones. Control of these infections and maintenance of biliary drainage are the main therapeutic aims. The development of intra epithelial neoplasia and invasive carcinoma are rare complications.We report a case of Caroli’s disease with the development of cholangiocarcinoma and review the literature.

Expression of Angiotensin II Receptor Type 1 Is Reduced in Advanced Rat Liver Fibrosis

In this study, we assessed the hypothesis that the expression of angiotensin II receptor type 1 (AGTR1) in liver tissue changes with increasing fibrosis, which would influence the antifibrotic efficacy of AGTR1 blockers. Rats were treated with candesartancilexetil (CAN) initiated 8 or 15 days after bile duct occlusion (BDO). Four weeks after BDO, AGTR1 mRNA and protein were decreased compared to those in sham-operated animals depending on the amount of fibrosis. Starting CAN early, but not late, reduced mRNA of profibrotic TGF-β, MMP2, and Smad2. However, CAN had no significant effect on collagen I, fibrosis, or intrahepatic resistance. In conclusion, progression of liver fibrosis reduces AGTR1 expression. Therefore, in our model, antifibrotic effects of CAN are insufficient to improve fibrosis or intrahepatic resistance. However, if AGTR1 blockade is started early, a decrease in essential profibrotic molecules is achieved. Hence, early initiation of therapy with AGTR1 blockers may be crucial for the prevention of cirrhosis.