K. Böker
Hannover Medical School
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Featured researches published by K. Böker.
The Lancet | 2001
Hans J. Schlitt; Annette Barkmann; K. Böker; Nikos Emmanouilidis; Jens Rosenau; Matthias J. Bahr; Günter Tusch; Michael P. Manns; Björn Nashan; Jürgen Klempnauer
BACKGROUND Renal dysfunction is a major complication of long-term immunosuppressive therapy with calcineurin inhibitors (CNI) in liver-transplant recipients. We undertook a randomised study to assess the safety and efficacy of CNI withdrawal and replacement by mycophenolate mofetil. METHODS 28 people who had had renal dysfunction attributable to suspected CNI toxicity after liver transplantation participated in the study. We replaced CNI with mycophenolate mofetil in a stepwise pattern in half the group (study patients); the other half (controls) stayed on CNI immunosuppression. Renal function, blood pressure, uric acid, and blood lipids were measured before and 6 months after study entry. Side-effects of medication and graft function were recorded throughout the study. FINDINGS At the end of the study, mean (SD) serum creatinine had fallen by 44.4 (48.7) micromol/L in study patients compared with 3.1 (14.3) micromol/L in controls; a mean difference of 41.3 micromol/L (95% CI 12.4-70.2). Moreover, systolic and diastolic blood pressure, and serum uric acid decreased significantly in the study group but not in the control group (mean [95% CI] between group differences 10.8 mm Hg [3.0-18.6], 5.0 mm Hg [0.9-9.2], and 83.1 micromol/L [12.7-153.6], respectively). There were no changes in cholesterol or triglyceride concentrations in either group. Side-effects were reported by eight of the study patients. Three reversible episodes of acute graft rejection occurred in study patients during mycophenolate mofetil monotherapy, whereas none occurred in the control group. INTERPRETATION Substitution of CNI by mycophenolate mofetil can improve renal function, blood pressure, and uric acid concentration of liver-transplant patients, but there is an increased rejection risk with mycophenolate mofetil monotherapy.
Journal of Hepatology | 2001
Jens Rosenau; Matthias J. Bahr; Hans L. Tillmann; Christian Trautwein; Jürgen Klempnauer; Michael P. Manns; K. Böker
BACKGROUND/AIMS Reinfection with hepatitis B virus (HBV) after liver transplantation (OLT) is associated with an unfavourable clinical course. Lamivudine/hepatitis B immune globulin (HBIG) combination treatment reduces reinfection rates. However, it is unclear at what time point lamivudine should be started and which HBIG doses are sufficient. METHODS Twenty-one patients receiving combination treatment were studied. Lamivudine was started up to 16.5 months before OLT and continued thereafter. HBIG was started intraoperatively and continued according to anti-HBs-titers. Median follow-up after OLT was 20 months. RESULTS Eleven patients received lamivudine pretreatment for >2 (median 6) months due to initial HBV-DNA-positivity (median 749 pg/ml). After initial lamivudine response HBV-DNA increased in two of them to concentrations above 10 pg/ml prior to OLT. Both had developed mutations in the YMDD motif and suffered from HBV reinfection 13 and 75 days postoperatively. Individual HBIG consumption was highly variable (range 787-4,766 lU/month). Twenty-two percent of anti-HBs titers measured before HBIG administration were below 100 IU/l. CONCLUSIONS Combined reinfection prophylaxis with lamivudine and HBIG is effective in patients with controlled viral replication at the time of OLT. However, pretransplantation lamivudine resistance is a risk factor for reinfection. Low dose HBIG maintenance therapy individualized according to anti-HBs-titers appears to be tenable.
The Lancet | 1996
Stefan Heringlake; Sabine Osterkamp; Christian Trautwein; Hans L. Tillmann; K. Böker; Scott Muerhoff; Isah K Mushahwar; Gerhard Hunsmann; Michael P. Manns
BACKGROUND The GB virus C (GBV-C) and the hepatitis G virus (HGV) have been detected in patients with acute indeterminant hepatitis and post-transfusion hepatitis. However, the role of the new hepatitis viruses in the aetiology of fulminant hepatitis is little understood. We investigated the presence of GBV-C/HGV in patients with fulminant hepatic failure. METHODS Serum samples from 22 German patients with fulminant hepatic failure and 106 symptom-free blood donors (controls) were studied for presence of GBV-C RNA by seminested reverse transcriptase PCR. Primer sequences were derived from the published gene sequences of the conserved NS3 region of the GBV-C prototype and the published isolates. Nucleotide and amino acid sequences of GBV-C-positive isolates, the control RNA, and the published HGV and GBV-C prototype sequences were compared by multiple sequence alignment. We also compared the GBV-C sequences of virus-positive patients who had fulminant hepatic failure with those of 19 patients with chronic hepatitis from our centre. In addition, we searched databases and published papers for further GBV-C helicase sequences in patients with non-fulminant hepatitis. FINDINGS GBV-C RNA was detected in 11 (50%) of the 22 patients with fulminant hepatic failure and in five (4.7%) of 106 control-group blood donors. Among the patients with fulminant hepatic failure, six of seven with fulminant hepatitis B and five of ten with fulminant non-A-E hepatitis were positive for GBV-C RNA. Analysis of nucleic acid sequences showed six mutations at defined positions in all 11 patients with fulminant hepatic failure who were positive for GBV-C. None of these mutations were found in the five GBV-C-positive control-group blood donors. Of the six nucleotide changes, four caused no amino acid changes, whereas two mutations at position 100 (G to T) and 102 (T to C) led to an alanine to serine change in the predicted translation product. However, comparison with GBV-C sequences of patients with non-fulminant hepatitis showed that this amino acid mutation was not specific for fulminant hepatic failure. The sequence-motif containing the six nucleotide mutations detected in all patients with fulminant hepatic failure was found in only two of 19 German patients with chronic hepatitis from our centre, and in only one of 88 GBV-C sequences from non-fulminant patients reported by others. INTERPRETATION The frequency of GBV-C RNA is higher in fulminant hepatic failure than in any other group of patients with hepatitis, particularly in patients with fulminant hepatitis B or fulminant non-A-E hepatitis. A specific strain of GBV-C may occur in serum of German patients with fulminant hepatic failure.
Journal of Hepatology | 1991
R. Müller; G. Gubernatis; Margarete Farle; Gabriele Niehoff; Heide Klein; Christian Wittekind; Günter Tusch; H.U. Lautz; K. Böker; Walter Stangel; R. Pichlmayr
Liver transplantation in HBs-antigen (HBsAg) positive allograft recipients is associated with a high risk of HBV recurrence some time after surgery. So far, results of measures to prevent recurrent HBV-infection by means of treatment with interferon, hepatitis B vaccination and short-term passive immunization with hepatitis B immunoglobulin (HBIg) or monoclonal antibody to HBsAg (anti-HBs) have been disappointing. In the present study the results of long-term, anti-HBs monitored passive immunization with HBIg is reported. In 23 HBsAg-positive liver transplant recipients an anti-HBs level of greater than or equal to 100 IU/l was maintained for 6 or 12 months, respectively. The rate of recurrent infection was found to be less than 20% under HBIg substitution, whereas 11 graft recipients with no or only short-term HBIg prophylaxis were reinfected by month 15 after transplantation. HBV recurrence was associated with chronic liver disease and recurrent cirrhosis in the allograft.
Transplantation | 2000
Annette Barkmann; Björn Nashan; Hartmut Schmidt; K. Böker; Nikos Emmanouilidis; Jens Rosenau; Matthias J. Bahr; Matthias W. Hoffmann; Michael P. Manns; Jürgen Klempnauer; Hans J. Schlitt
BACKGROUND Renal dysfunction caused by treatment with the calcineurin inhibitors (CNI) is a major problem in the long-term course after liver transplantation. PATIENTS In 22 liver graft recipients with renal dysfunction and stable graft function between 3 weeks and 12 years after transplantation, CNI were substituted by MMF at a final dose of 1.5-3 g/day between October 1996 and October 1998. METHODS In a prospective non-randomized study, the development of renal function, the side effects of MMF medication, and the stability of liver function were analyzed for a mean follow-up of 15 months. Results. (1) MMF was withdrawn in four patients for major side effects between 1 and 7 months after study entry; eight patients had minor side effects. (2) Six months after study entry, renal function had improved in 17 of the 22 study patients; mean serum creatinine +/-SD (micromol/L) was 201+/-77 at entry and 153+/-65 after 3 months (P<0.001). (3) Improvement occurred in 11 of 15 patients with creatinine elevation > or =12 months and in 6 of 6 patients with creatinine elevation < or =6 months. (4) One patient developed transient liver dysfunction and a second required retransplantation for progressive cholestasis but without signs of rejection. CONCLUSIONS In patients who undergo liver transplantation, substitution of CNI by MMF leads to improvement of acute as well as chronic renal dysfunction in most cases. Side effects of MMF may be limiting in some patients, and the immunological consequences remain to be studied.
Transplantation | 1994
K. Böker; B. Ringe; Martin Krüger; R. Pichlmayr; Michael P. Manns
New concepts for the treatment of hepatitis B in immunocompromised patients are urgently needed. We describe our first experience with the new antiviral agent famciclovir in combination with a short course of prostaglandin E in a patient with severe hepatitis B after liver transplantation. Initial treatment with prostaglandin E reduced the inflammatory activity, as measured by transaminase activities, but did not affect viral replication. Consecutive long-term treatment with famciclovir further normalized liver function and profoundly suppressed viral replication. HBeAg and HBV-DNA -PCR all became negative and only HBsAg persisted. Histology documented marked reduction of cellular infiltration. The patient completely recovered and is back to regular work as a teacher.
Clinical Nutrition | 1994
M.J. Müller; K. Böker; Oliver Selberg
Hypermetabolism is not a constant feature of liver cirrhosis. It may occur in up to 18% of cirrhotics. Most of the deviations are due to increases in resting energy expenditure (REE). Dietary induced thermogenesis (DIT) is normal or slightly increased whilst the thermic effect of exercise TEE is of minor importance in cirrhosis. The increase in REE which reflects a systemic manifestation of liver disease cannot be identified by the clinical and biochemical measures of liver function. An increased REE is frequently seen in malnourished patients and this is mainly due to disproportional loss in muscle mass. Some cirrhotic patients cannot reduce REE in response to weight loss. This problem is not specific for liver cirrhosis but is also seen in other cachectic groups of patients. Adjustment of REE per kg fat free mass (FFM) may lead to erroneous conclusions (i) because of the non linearity of REE over the range of FFM and (ii) the different contributions of muscle mass and non-muscle body cell mass (BCM) to FFM over the range of FFM. There is circumstantial evidence that the metabolic rate per kg BCM is increased in malnourished cirrhotics. More specifically, cirrhosis increases in REE are associated with a deterioration in hepatic circulation. Increased sympathetic nervous system activity is frequently seen in cirrhosis and may provide a link between between reduced nutritive portal flow and increased whole body oxygen consumption. Increased REE is also associated with weight loss, a poorer liver function and a higher mortality after liver transplantation and thus may have prognostic value. Taken together, REE is variable in patients with cirrhosis. Hypermetabolism is seen in malnourished patients and those with impaired splanchnic hemodynamics. Hypermetabolism is associated with a poorer outcome after liver transplantation.
The American Journal of Gastroenterology | 2000
Christian Trautwein; Martin Possienke; Hans-Jörg Schlitt; K. Böker; Roland Horn; R. Raab; Michael P. Manns; Georg Brabant
OBJECTIVE:Osteoporosis is frequently found in patients with cholestatic liver disease (primary biliary cirrhosis/primary sclerosing cholangitis) and chronic viral hepatitis. There is limited information about the long-term effect of liver transplantation (OLT) on bone metabolism. The aim of this study was to investigate the effect of liver transplantation on bone metabolism in patients with cholestatic and viral liver diseases.METHODS:We randomly recruited 193 patients with chronic viral hepatitis or cholestatic liver diseases. Bone density (Z-score) and markers of bone metabolism (intact parathyroid hormone [iPTH], PTH 70–84, osteocalcin, procollagen, telopeptide, and vitamin D) were determined before and at time points (< and > 24 months) post-OLT.RESULTS:Before OLT, bone density (Z-score) was decreased in patients with cholestatic (−1) and viral (−0.4) liver diseases. In both groups bone density continued to decrease in the periods up to and more than 24 months after OLT. In the cholestatic group, bone density decreased significantly compared to pre-OLT (p < 0.05) and to the viral hepatitis group (p < 0,001). Markers of bone metabolism showed that after OLT, bone metabolism was enhanced and shifted versus bone resorption. Immunosuppressive drug therapy (glucocorticoids, cyclosporin, FK 506) directly correlated with increased bone metabolism post-OLT.CONCLUSIONS:Bone loss is a long-term problem after OLT, particularly in patients with cholestatic liver diseases. Drug therapy is a main factor of bone loss. Pre- and post-OLT therapy to reduce bone loss is recommended.
Nutrition & Metabolism | 2010
Gemma Brufau; Matthias J. Bahr; Bart Staels; Thierry Claudel; Johann Ockenga; K. Böker; Elizabeth Murphy; Kris Prado; Frans Stellaard; Michael P. Manns; Folkert Kuipers; Uwe J. F. Tietge
Bile acids (BA) have recently been shown to increase energy expenditure in mice, but this concept has not been tested in humans. Therefore, we investigated the relationship between plasma BA levels and energy expenditure in humans. Type 2 diabetic (T2DM) patients (n = 12) and gender, age and BMI-matched healthy controls (n = 12) were studied before and after 8 weeks of treatment with a BA sequestrant. In addition, patients with liver cirrhosis (n = 46) were investigated, since these display elevated plasma BA together with increased energy expenditure. This group was compared to gender-, age- and BMI-matched healthy controls (n = 20). Fasting plasma levels of total BA and individual BA species as well as resting energy expenditure were determined. In response to treatment with the BA sequestrant, plasma deoxycholic acid (DCA) levels decreased in controls (-60%, p < 0.05) and T2DM (-32%, p < 0.05), while chenodeoxycholic acid (CDCA) decreased in controls only (-33%, p < 0.05). Energy expenditure did not differ between T2DM and controls at baseline and, in contrast to plasma BA levels, was unaffected by treatment with the BA sequestrant. Total BA as well as individual BA species did not correlate with energy expenditure at any time throughout the study. Patients with cirrhosis displayed on average an increase in energy expenditure of 18% compared to values predicted by the Harris-Benedict equation, and plasma levels of total BA (up to 12-fold) and individual BA (up to 20-fold) were increased over a wide range. However, neither total nor individual plasma BA levels correlated with energy expenditure. In addition, energy expenditure was identical in patients with a cholestatic versus a non-cholestatic origin of liver disease while plasma total BA levels differed four-fold between the groups. In conclusion, in the various (patho)physiological conditions studied, plasma BA levels were not associated with changes in energy expenditure. Therefore, our data do not support an important role of circulating BA in the control of human energy metabolism.
Journal of Hepatology | 1997
M. Caselitz; H. Link; R. Hein; H. Maschek; K. Böker; H. Poliwoda; Michael P. Manns
BACKGROUND Several cases have been reported showing clearance of HBsAg in chronic hepatitis B carriers due to adoptive transfer of immunity by an hepatitis B immunised bone marrow. CASE REPORT We report on a 27-year-old man with chronic myelocytic leukemia and asymptomatic chronic hepatitis B who received allogeneic bone marrow transplantation (BMT). The donor was his HLA identical brother with natural immunity against hepatitis B. Before BMT the donor had received an additional dose of recombinant hepatitis B vaccine. Twenty days after BMT alanine aminotransferase levels increased and graft versus host disease of the skin was observed. Elevation of liver enzymes was initially attributed to graft versus host disease of the liver and the patient received high doses of steroids in addition to standard immunosuppression. Alanine aminotransferase levels increased up to a maximum on day 52 while the HBV DNA level peaked on day 38 after BMT. A liver biopsy showed reactivation of hepatitis B and treatment with steroids was tapered down. Although alanine aminotransferase and HBV DNA levels decreased, liver function deteriorated. The patient died 130 days after BMT due to liver failure. CONCLUSION This report indicates that disturbance of the balance between HBV replication and immune control after BMT may result in fatal reactivation of hepatitis B. Careful monitoring, including HBV DNA level and early liver biopsy, of patients with chronic hepatitis B undergoing BMT as well as determination of the HBV immune status of the BMT donor is suggested and necessary.