K. Boeker
Hochschule Hannover
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Featured researches published by K. Boeker.
Journal of Clinical Oncology | 1999
Hans J. Schlitt; Michael Neipp; Arved Weimann; Karl J. Oldhafer; Ekkehard Schmoll; K. Boeker; Björn Nashan; Stefan Kubicka; H. Maschek; Günter Tusch; Rudolf Raab; Burckhardt Ringe; Michael P. Manns; R. Pichlmayr
PURPOSE Tumor recurrence is the major limitation of long-term survival after liver transplantation for hepatocellular carcinoma (HCC) or fibrolamellar carcinoma (FLC). Understanding tumor-biologic characteristics is important for selection of patients and for development of adjuvant therapeutic strategies. PATIENTS AND METHODS The study included 69 patients who underwent potentially curative liver transplantation for HCC/FLC and survived for more than 150 days; minimum follow-up was 33 months. Frequency, localization, and timing of recurrence were analyzed and compared with primary tumor and patient characteristics. RESULTS Tumor recurrence was observed in 39 patients at 67 locations. Hematogenous spread was the major route of tumor recurrence (87%), and the most frequent sites were the liver (62%), lung (56%), and bone (18%). Parameters associated with recurrence were absence of cirrhosis, tumor size greater than 5 cm, more than five nodules, vascular infiltration, and International Union Against Cancer (UICC) stage IVA. Selective intrahepatic recurrence was found in nine patients (23%); it was associated with highly differentiated tumors, lack of vascular infiltration, and male sex. Recurrence at multiple sites was found predominantly in young patients (< or = 40 years) and for multicentric (> 5) primary tumors. Recurrences were observed within a wide time range after transplantation (43 to 3,204 days; median, 441 days); late recurrences (> 1,000 days, n = 8) were associated with highly differentiated or fibrolamellar tumors and low UICC stages. Surgical treatment was the only therapeutic option associated with prolonged survival after recurrence. CONCLUSION In transplant recipients, hepatocellular carcinomas vary considerably in their pattern and kinetics of metastases. Tumor cells may persist in a dormant state for long time periods before giving rise to clinical metastases. Surgical treatment of recurrence should be considered whenever possible.
Transplantation | 2002
Jens Rosenau; Matthias J. Bahr; Reinhard von Wasielewski; Michael Mengel; Hartmut Schmidt; Björn Nashan; Hauke Lang; Jürgen Klempnauer; Michael P. Manns; K. Boeker
BACKGROUND Patients suffering from hepatic metastases of neuroendocrine tumors (NET) are potential candidates for orthotopic liver transplantation. Because recurrence rates are high and outcome is variable, prognostic indicators are required. The aim of our study was to identify predictors of long-term survival with a focus on the impact of tumor biology. METHODS We retrospectively analyzed 19 patients who received an orthotopic liver graft for metastatic NET at the Medizinische Hochschule Hannover. Expression of Ki67, E-cadherin, and p53 was studied immunohistochemically in metastases of neuroendocrine tumors of the explanted livers. RESULTS Patients were followed up to 146 months after liver transplantation. Six patients died during follow-up. The resulting 1-, 5-, and 10-year survival rates are 89%, 80%, and 50%, respectively. All deaths during long-term follow-up were tumor-associated. Recurrence was diagnosed in 12 patients between 2 weeks and 48 months after liver transplantation. Three patients are without tumor recurrence more than 8 years after liver transplantation. Survival in the 5 patients with low Ki67 and regular E-cadherin staining was significantly better than in the 12 patients with high Ki67 or aberrant E-cadherin expression (7-year survival 100% vs. 0%, respectively, log rank P=0.007). p53 expression did not significantly improve prognostic accuracy. CONCLUSIONS We conclude that analysis of Ki67 and E-cadherin expression may improve the identification of patients with a favorable prognosis after liver transplantation for metastatic neuroendocrine tumors.
Clinica Chimica Acta | 2002
K. Boeker; Christian I. Haberkorn; Dirk Michels; Peer Flemming; Michael P. Manns; Ralf Lichtinghagen
BACKGROUND Circulating levels of tissue inhibitor of metalloproteinase (TIMP)-1 and matrix metalloproteinase (MMP)-2 are investigated as parameters for the diagnosis of fibrosis in chronic liver disease. We evaluated their diagnostic potential in comparison to hepatic histology, serum hyaluronate and standard liver function tests. METHODS Commercially available ELISA assays were used to study circulating values of TIMP-1 and MMP-2 (Bindazyme, Biotrak, Quantikine) in patients with chronic hepatitis C (CAH; n=59), hepatitis C virus-induced cirrhosis (n=19) and 30 healthy controls. Hepatic histology was evaluated using the Hepatitis-Activity-Index according to Ishak et al. [J. Hepatol., 22 (1995) 696-699], quantifying separately inflammatory activity and fibrosis. RESULTS Normal ranges for TIMP-1 and MMP-2 values differed for the different assays. Nevertheless, the various assays showed similar diagnostic ability and linear correlation. MMP-2 values were similar in controls and in CAH patients with and without fibrosis, but increased significantly in cirrhosis. TIMP-1 values showed a steady increase from normal to CAH without fibrosis, hepatitis with fibrosis, and cirrhosis. The diagnostic potential of serum MMP-2 to detect fibrosis was low with a sensitivity of 7% in the two assays used and an overall diagnostic efficiency of 56% and 58%. The potential of circulating MMP-2 to detect cirrhosis was higher with sensitivities of 74% and 83% and specificities of 96% and 100%, resulting in a diagnostic efficiency of 92% in the different assays. Plasma TIMP-1 values detect fibrosis with a sensitivity of 52% and 67% and a specificity of 68% and 88% resulting in overall efficiency rates of 68% and 71%, respectively. TIMP-1 values detect cirrhosis with 100% sensitivity but only 56% and 75% specificity. The diagnostic potential of circulating TIMP-1 was similar to that of hyaluronate and better than that of enzymes or albumin values. CONCLUSION Plasma values of TIMP-1 and MMP-2 are able to detect cirrhosis with high sensitivity. TIMP-1 values also detect fibrosis with comparable efficiency. Regular determinations of both TIMP-1 and MMP-2 in CAH patients may be used as indicators of increasing fibrosis and the development of cirrhosis.
Journal of Hepatology | 2001
Ralf Lichtinghagen; Dirk Michels; Christian I. Haberkorn; Burkhard Arndt; Matthias J. Bahr; Peer Flemming; Michael P. Manns; K. Boeker
BACKGROUND/AIMS To study whether expression of matrix metalloproteinases and their inhibitors correlate with ongoing fibrogenesis, we measured hepatic mRNA levels of matrix metalloproteinase (MMP) -2, MMP-7, and MMP-9 as well as tissue inhibitor of metalloproteinase (TIMP) -1, TIMP-2, and TIMP-3 and compared it to histology, procollagen IV alpha-1 chain mRNA levels, and biochemical parameters in patients with chronic active hepatitis C (CAH). METHODS Quantitative reverse transcription-polymerase chain reaction/enzyme-linked immunossorbent assay using in vitro transcribed competitor and standard RNA were performed from ten normal livers (N), 29 CAH liver biopsies and seven samples with hepatitis C virus (HCV)-induced end-stage cirrhosis (Ci). RESULTS From N to Ci both TIMP and MMP RNA expression increased. However, none of the RNA levels differed significantly between CAH patients with and without fibrosis. Non-parametric correlation analysis and receiver operating characteristics curves show that MMP-2, MMP-7, and TIMP-1 provide the best discrimination between cirrhosis and pre-cirrhotic stages. They also correlate with histologic and biochemical inflammatory activity and with procollagen IV mRNA. CONCLUSION Hepatic fibroproliferation is associated with alterations of hepatic TIMP and MMP expression. The relation of hepatic TIMP and MMP mRNA levels to disease stage and inflammatory activity underlines their potential as diagnostic markers in chronic liver disease.
Annals of Surgery | 1999
Hans J. Schlitt; Peter N. Meier; Björn Nashan; Karl J. Oldhafer; K. Boeker; Peer Flemming; Rudolf Raab; Michael P. Manns; R. Pichlmayr
OBJECTIVE To assess the feasibility, morbidity, mortality, and clinical success rate of surgical reconstruction of the biliary system in patients with ischemic-type biliary lesions in their liver graft. SUMMARY BACKGROUND DATA After liver transplantation, strictures in the biliary tree with secondary sludge formation can occur in the absence of vascular problems. Jaundice, pruritus, and recurrent cholangitis are predominant clinical features leading to considerable morbidity. Interventional measures are the first-line treatment but are frequently only of transient success. Retransplantation is usually considered when interventional treatment is not effective. METHODS Surgical exploration and reconstruction was performed in 17 patients with ischemic-type biliary strictures at a median of 2 years after liver transplantation. Findings during surgery, surgical strategies, and postsurgical courses are described. Clinical symptoms and biochemical parameters of cholestasis and liver function were analyzed in the postsurgical course. RESULTS During surgery, all 17 patients were found to have strictures or sclerotic changes involving the hepatic bifurcation and extrahepatic bile duct. Sludge or stones were present in nine patients. In 14 patients with viable bile ducts proximal to the bifurcation, surgical reconstruction was performed by resection of the bifurcation and hepaticojejunostomy. In three patients with more extensive biliary destruction, portoenterostomy with or without peripheral hepatojejunostomy was performed. The prevalence rate of biliary infection at surgery was 93%; the predominant organisms were Candida and enterococci. The perioperative mortality rate was 0%. Clinical symptoms and biochemical parameters became normal or were considerably improved in 14 of 16 patients (88%). CONCLUSIONS The hepatic bifurcation seems to be a predominant site for ischemic-type biliary changes after liver transplantation. Surgical treatment by resection of the bifurcation and reconstruction by high hepaticojejunostomy is a safe and highly effective approach leading to cure or persistent major improvement in most patients.
Clinical Science | 2003
Ralf Lichtinghagen; Matthias J. Bahr; Michael Wehmeier; Dirk Michels; Christian I. Haberkorn; Burkhard Arndt; Peer Flemming; Michael P. Manns; K. Boeker
Matrix metalloproteinases (MMPs) are central to tissue remodelling; however, little is known about the temporal pattern and differential regulation of hepatic MMP expression in the course of chronic human liver disease. Using quantitative reverse transcription-PCR ELISA assays, we studied hepatic mRNA expression of MMP-1, -2, -3, -7, -9, -10, -11, -13 and -14 in patients with chronic hepatitis C and hepatitis C virus-induced end-stage liver cirrhosis and controls. Results were compared with histology, hepatic expression of tissue inhibitor of metalloproteinases (TIMP)-1, -2 and -3, procollagen types I and IV, laminin, and with circulating protein levels of hyaluronate, TIMP-1 and -2 and MMP proenzymes, as measured by ELISA. The impact of the MMP-3(-1171) promoter polymorphism on hepatic MMP-3 expression was analysed. Hepatic mRNA expression data identified differentially regulated groups of MMPs during the course of chronic hepatitis C, showing either steadily increasing mRNA expression with disease progression (MMP-1, -2, -7 and -14) or transiently elevated expression (MMP-9, -11 and -13). The first group closely correlated to the parameters of fibrogenesis. Hepatic MMP-3 expression was unrelated to disease stage, but was determined by the MMP-3(-1171) promoter polymorphism. In conclusion, MMP expression during the course of chronic hepatitis C appears to be a closely regulated process, with different clusters of coordinately regulated MMP genes being identified.
Transplantation | 1998
Heiner Wedemeyer; Klaus Pethig; Doris Wagner; Peer Flemming; Petra Oppelt; Dieter R. Petzold; Axel Haverich; Michael P. Manns; K. Boeker
BACKGROUND Hepatitis B is common in organ transplant recipients. It adversely affects the prognosis after liver and kidney transplantation. The long-term outcome of hepatitis B virus (HBV) infection in heart transplant recipients has not been studied before. METHODS Between July 1984 and June 1993, 436 patients underwent heart transplantation at the Hannover Medical School. A total of 345 patients survived for more than 1 year and were included in this study. Of these, 74 were found to be hepatitis B surface antigen (HBsAg)-positive during follow-up; 69 acquired HBV infection at known time points 25+/-17 months after transplantation, and 5 had already been infected before heart transplantation. Mean follow-up was 105 (range, 25-157) months. RESULTS Patients developed significant alanine aminotransferase (ALT) elevations after HBV infection, which peaked and then remained above normal. Preinfection levels of ALT were 15.4+/-6.4 U/L, peak values were 71.2+/-47.2 U/L, and mean values after HBV infection were 28.9+/-14.6 U/L. All patients remained HBsAg-positive. Thirteen patients (18%) became HBeAg-negative during follow-up, 10 with negative quantitative HBV-DNA assays. Mean HBV-DNA levels in the remaining patients were 292+/-267 (range, 0-978) pg/ml. Thirty-four patients died during follow-up (45.9%) compared to 78/271 (28.8%) in the control group (P=0.008). Six of the HBsAg-positive patients (17.1%) died of liver failure 6.2-10.6 years (mean, 8.6) after transplantation. Histology of 25 HBsAg-positive patients more than 5 years after infection revealed severe fibrosis or cirrhosis in 14 (56%), mild fibrosis in 9 (36%), and chronic hepatitis without fibroproliferation in 2 (8%). CONCLUSIONS Hepatitis B infection after heart transplantation leads to chronic liver disease in the majority of the affected patients, causing cirrhosis in more than 55% within the first decade after transplantation. Liver failure is a common cause of death in the infected group of patients. Active HBV vaccination is mandatory for all organ transplant candidates, in particular before heart transplantation.
Hepatology Research | 1999
Ralf Lichtinghagen; Claudia Steinmetz; Birte Pehle; Karin Breitenstein; Thomas Seifert; K. Boeker
Abstract To study the value of matrix metalloproteinases as indicators of hepatic fibroproliferation, expression of MMP-1, MMP-2, MMP-7 and MMP-9 was studied in healthy controls, patients with chronic hepatitis C (CAH) and in HCV-induced cirrhosis. Western blot revealed an increase for MMP-1 in CAH with histologically detectable fibrosis and diminished amounts in cirrhosis. MMP-2 was unchanged in CAH and cirrhosis, while there was an increase of MMP-7 in 8 of 18 cirrhotic liver samples. Northern analysis demonstrated in cirrhosis an increase of MMP-7 mRNA more strongly than MMP-2 mRNA. ELISA studies demonstrated a trend towards an increase in circulating MMP-2 levels and a reduction in circulating MMP-9 levels with advancing fibrosis. RT-PCR demonstrated transcripts for MMP-1, MMP-2 and MMP-7 in hepatic tissue and isolated stellate cells. MMP-9 transcripts were only found in white blood cells. Hepatic expression of MMP-1, MMP-2 and MMP-7 is increased in chronic hepatitis C, but the resulting proenzyme levels are not sufficiently different to allow discrimination between patients with and without fibroproliferation. MMP-9 shows significant changes in serum, with a progressive reduction from controls to cirrhosis, but is most likely derived from extrahepatic sources.
Metabolic Brain Disease | 2001
K. Boeker
The term acute liver failure (ALF) characterizes a disorder in which the metabolic and excretory function of the liver is severely impaired in patients with previously healthy livers. This definition clearly separates ALF from the final stages of chronic liver diseases, in which progressive cessation of liver function is sometimes designated as “acute on chronic” liver failure. True ALF is characterized by a combination of failing liver function (jaundice and impaired synthesis of clotting factors) and neurologic symptoms with marked hepatic encephalopathy. It is a severe syndrome of considerable dynamics, in which untreated individuals may die within only a few days (O’Grady, 1996). According to the time course of the evolving disease ALF can be further subdivided into “hyperacute (or fulminant) liver failure,” in which the time between appearance of jaundice and encephalopathy is less than 7 days, classic “acute liver failure,” when the interval is 8–28 days, and “subacute liver failure” when this takes more than 28 days (Hoofnagle et l., 1995). This classification, although not universally accepted, can be helpful in assessing the prognosis in individual cases; patients with hyperacute liver failure tend to have a better prognosis than those with more protracted forms of the syndrome. When treated with supportive intensive care, liver failure of rapid onset may show regeneration of liver function and subsequent recovery of the patient within days.
Liver International | 2018
Benjamin Maasoumy; Peter Buggisch; Stefan Mauss; K. Boeker; Tobias Müller; Rainer Günther; Tim Zimmermann; Michael P. Manns; Christoph Sarrazin; D Hüppe; H. Wedemeyer; Johannes Vermehren
AASLD/IDSA treatment guidelines for hepatitis C virus (HCV) infection state that testing for quantitative HCV RNA can be considered at the end of antiviral treatment (EOT) with interferon‐free regimens. However, it remains unclear how to respond to a detectable or even quantifiable HCV RNA result. The aim of this study was to analyse the frequency and predictive value of detectable and quantifiable HCV RNA results at the EOT in patients with HCV genotype 1 infection treated with ledipasvir (LDV) and sofosbuvir (SOF) ± ribavirin (RBV) in a large real‐world cohort.