[Extrahepatic cholangiocarcinoma: current state of palliation therapy]. / Extrahepatische Gallenwegstumoren: aktueller Stand der palliativen Therapie.

INTRODUCTION: Decompression of bile ducts is the priority objective in the non-curative stage of hilar cholangiocarcinoma. Only this will prevent or slow down infectious complications and secondary biliary cirrhosis thereby sustaining the quality of life. KEY STATEMENTS: At present, photodynamic therapy combined with insertion of an endoprosthesis seems to be best documented and most appropriate therapy. METHODS: Data from a selective literature search combined with our clinical experience were evaluated. CONCLUSIONS: Therapeutic measures should match the dissemination and stage of the tumor: in locally advanced or progressing disease (stage III) a local ablating therapy, in systemically progressing disease (stage IV) systemic chemotherapy should be utilised.

Quantification of HBsAg and HBV-DNA during therapy with peginterferon alpha-2b plus lamivudine and peginterferon alpha-2b alone in a German chronic hepatitis B cohort.

BACKGROUND: Peginterferon alpha-2b (PEG-IFNa2b) and lamivudine are efficient treatment options for chronic hepatitis B virus (HBV) infection. We assumed that a combination therapy of PEG-IFNα-2b plus lamivudine will be more effective than PEG-IFNα-2b alone concerning loss of HBV-DNA, HBeAg seroconversion, and HBsAg reduction. PATIENTS AND METHODS: Patients with chronic hepatitis B were randomised to nine months treatment with PEG-IFNα-2b 1.5 µg/kg o. i. w. or PEG- IFNα-2b plus lamivudine 100 mg/d. The study was designed with 60 patients per treatment arm. The primary endpoint was defined as loss of HBV-DNA (< 400 copies/mL) 24 weeks after the end of therapy. HBV-DNA (PCR), HBsAg (Architect, Abbott), and HBeAg (Axsym, Abbott) were determined prior to and at the end of treatment as well as at follow-up. HBV-genotypes were determined by Innolipa (Innogenetics). RESULTS: Only 32 patients were randomised to combination therapy and 27 individuals to monotherapy due to low recruitment rates. On treatment reduction of HBV-DNA was significantly higher during combination therapy compared to PEG-IFNa-2b monotherapy (- 4.60 ± 2.71 vs. - 2.41 ± 2.17 log; p = 0.003). However, there was no difference in the number of cases achieving HBV-DNA < 400 copies/mL, ALT normalisation, or HBeAg seroconversion at follow-up. None of the parameters was significantly related to HBV-genotypes. In a post-hoc analysis serum HBsAg levels were analysed as an additional prognostic parameter for treatment response (n = 29). Combination therapy showed a stronger, but not significant HBsAg decline during (- 0.7 ± 1.17 log IU/mL vs. - 0.26 ± 0.61 log IU/mL; p = 0.35) and after therapy (- 0.68 ± 1.29 log IU/mL vs. - 0.24 ± 0.56 log IU/mL; p = 0.82). Two of three cases with a 2-log HBsAg decline to HBsAg levels < 100 IU/mL eliminated HBsAg during long-term follow-up. CONCLUSION: The study was underpowered with respect to the primary endpoint due to low recruitment rates. However, in the post-hoc analysis HBsAg decline was over two-fold stronger at the end of treatment and follow-up after combination therapy and did not rebound after lamivudine withdrawal. These results may indicate the usefulness of future combination therapies without discontinuation of nucleos(t)ide analogues.

Disorders of bile acid metabolism in cholesterol gallstone disease.

The aim of the study was to evaluate the metabolism of individual bile acids in patients with cholesterol gallstone disease. Therefore, we determined pool size and turnover of deoxycholic (DCA), cholic (CA), and chenodeoxycholic acid (CDCA) in 23 female gallstone patients classified according to their gallbladder function and in 15 healthy female controls. Gallstone patients had normal hepatic bile acid synthesis, but, depending on gallbladder function, differed with respect to turnover and size of the bile acid pools: Patients with well-emptying gallbladder (group A, n = 9) had enhanced turnover and reduced pools of CA (-46%; P less than 0.01 vs. controls) and CDCA (-24%; P less than 0.05), but normal input and size of the DCA pool. With reduced gallbladder emptying (less than 50% of volume; group B, n = 6), turnover and pools of CA, CDCA, and DCA were similar as in controls. Patients with loss of gallbladder reservoir (group C, n = 8) had increased input (+100%; P less than 0.01) and pool size of DCA (+45%; P = 0.07) caused by rapid conversion of CA to DCA, while the pools of CA (-71%; P less than 0.001 vs. controls) and CDCA (-36%; P less than 0.05) were reduced by enhanced turnover. Thus, in patients with cholesterol gallstones, the pools of primary bile acids are diminished, unless gallbladder emptying is reduced. Furthermore, in a subgroup of gallstone patients, who had completely lost gallbladder function, the CA pool is largely replaced by DCA owing to rapid transfer of CA to the DCA pool. This probably contributes to supersaturation of bile with cholesterol.

Effects of cholecystectomy on the kinetics of primary and secondary bile acids.

Removal of the gallbladder is thought to increase formation and pool size of secondary bile acids, mainly deoxycholic acid (DCA), by increased exposure of primary bile acids (cholic acid [CA], chenodeoxycholic acid [CDCA]) to bacterial dehydroxylation in the intestine. We have tested this hypothesis by simultaneous determination of pool size and turnover of DCA, CA, and CDCA in nine women before and at various intervals after removal of a functioning gallbladder. An isotope dilution technique using marker bile acids labeled with stable isotopes (2H4-DCA, 13C-CA, 13C-CDCA) was used. After cholecystectomy, concentration and output of bile acids relative to bilirubin increased (P less than 0.02) in fasting duodenal bile and cholesterol saturation decreased by 27% (P less than 0.05) consistent with enhanced enterohepatic cycling of bile acids. Three months after removal of the gallbladder bile acid kinetics were in a new steady state: pool size and turnover of CDCA were unchanged. Synthesis of CA, the precursor of DCA, was diminished by 37% (P = 0.05), probably resulting from feedback inhibition by continuous transhepatic flux of bile acids. The fraction of CA transferred after 7 alpha-dehydroxylation to the DCA pool increased from 46 +/- 16 to 66 +/- 32% (P less than 0.05). However, this enhanced transfer did not lead to increased input or size of the DCA pool, because synthesis of the precursor CA had decreased.

A CDE/CHR tandem element regulates cell cycle-dependent repression of cyclin B2 transcription.

Cyclin B is an important regulator of progression through the cell division cycle. The oscillating appearance of cyclin B1 and B2 proteins during the cell cycle is in part due to fluctuating mRNA levels. We had identified earlier a tandem promoter element named cell cycle-dependent element (CDE) and cell cycle genes homology region (CHR) which regulates cell cycle-dependent transcription of cdc25C, cyclin A and cdc2. Here we describe that cyclin B2 transcription is repressed through a novel CDE/CHR element in resting and G(1) cells. By relief of this repression in S and G(2) oscillating expression of cyclin B2 mRNA is achieved during the cell cycle.

Apoptosis and the expression of Fas and Fas ligand (FasL) antigen in rejection and reinfection in liver allograft specimens.

BACKGROUND AND METHODS: To investigate the frequency of apoptosis and the expression of Fas/Fas ligand (FasL) in liver allografts, we examined 97 biopsy specimens from 62 patients after orthotopic liver transplantation. The results of the biopsies were as follows: acute allograft rejection (n=32); hepatitis C virus (HCV) reinfection (n=18); cytomegalovirus infection (n=5); acute rejection plus HCV reinfection (n=3); and stable graft function (n=30); and after treatment of acute rejection (n=9). RESULTS: Apoptotic cells were found in all cases examined, and their frequency increased significantly during acute rejection (0.17 vs. 9.0; P<0.05). The immunoreactivity of Fas and FasL antigen was higher in specimens with acute rejection than in those with stable graft function. Increased apoptosis, Fas, and FasL expression, however, were also seen in HCV reinfection. CONCLUSION: We conclude that apoptosis plays an important role in the hepatocellular damage observed in acute rejection and also in HCV reinfection. However, these parameters are, taken by themselves, not useful as indicators of acute rejection or HCV reinfection.

Alloreactivity of natural killer cells in allogeneic liver transplantation.

BACKGROUND: The cytolytic attack of natural killer (NK) cells is blocked by recognition of the idiotypic phenotype of certain polymorphisms in HLA class I molecules, specifically by HLA-C alleles (Asn77, Lys80 or Ser77, Asn80) or HLA-Bw4 allotypes. Because liver allograft rejection is associated closer with mismatch in HLA class I than class II, we investigated the role of NK cells in acute hepatic allograft rejection in vivo/in vitro. METHODS: The HLA pattern was typed with serological and polymerase chain reaction (PCR) techniques. In 31 liver transplantations, mononuclear cells from donor spleen and peripheral blood of recipients (before/after transplantation) were cultured in mixed lymphocyte cultures (MLC). MLC-derived effector cells were analyzed by flow cytometry and tested in 51Cr-release assays. RESULTS: Patients with NK allospecific constellations tended to have higher numbers of NK cells in peripheral blood during the first 4 weeks after transplantation, and patients' lymphocytes stimulated with donor cells had a significantly higher cytotoxic activity on days 14 and 21 compared with patients without NK allospecificity. However, acute rejection occurred with similar frequency in both groups (31% with allospecific constellations vs. 40% without). Moreover, acute rejection episodes were not associated with an increase in NK cells in vivo or enhanced cytotoxicity of NK cells to donor target cells. CONCLUSIONS: Under standard immunosuppressive therapy, NK allospecific constellations did not seem play a major role in acute hepatic allograft rejection. Strategies to prevent or treat NK allospecific constellations after liver transplantation are not likely to reduce the incidence or severity of acute allograft rejection.

Distribution and pharmacokinetics of Photofrin in human bile duct cancer.

Prognosis of patients with bile duct tumors is mostly poor due to late diagnosis and a lack of adequate curative and palliative treatment modalities. To evaluate the potential of photodynamic therapy (PDT) as a novel and alternative treatment approach, we have investigated the uptake and tumor-specific localization of the photosensitizer Photofrin in human biliary tract neoplasms. We have quantified the distribution and the pharmacokinetics of Photofrin in normal and tumor tissue biopsies of the human bile duct by quantitative fluorescence microscopy and digital image analysis of cryosections. Fluorescence intensities (expressed as a percentage of a standard) are 19.0 +/- 11.4% and 25.2 +/- 12.7% for tumors and 10.9 +/- 2.9% and 13.2 +/- 9.1% (mean +/- SD) for normal bile duct tissue at 24 h (n = 5) and 48 h (n = 8) after Photofrin administration (2 mg kg-1 i.v.), respectively, and decrease afterwards in normal bile duct tissue over the period of investigation (4-35 days). The ratios of fluorescence in tumor versus normal tissue are found to be 1.7 +/- 0.7 and 2.3 +/- 1.2 (mean +/- SD) at days one and two after Photofrin administration, respectively. Thus, Photofrin preferentially accumulates in bile duct neoplasms, reaching peak values during the first two days. These data suggest that laser irradiation should be performed within this period after Photofrin injection to achieve tumor selectivity of PDT for effective treatment of bile duct carcinoma.

[Percutaneous drainage treatment of primary liver abscesses]. / Die perkutane Drainagebehandlung primärer Leberabszesse.

28 primary liver abscesses, including 9 amoebic abscesses, in 24 patients were drained percutaneously. Indication for drainage in amoebic abscesses was imminent rupture and clinical symptoms as pleural effusion, lung atelectasis and pain. 95% of the primary abscesses were cured by percutaneous drainage and systemic antibiotic treatment. There was one recurrence of abscess, which was managed surgically. Reasons for drainage failure were: tumour necrosis and tumour perforation with secondary liver abscess.

[Clinical studies in liver transplantation]. / Klinische Studien in der Lebertransplantation.

Clinical liver transplantation became an established therapy of end-stage liver disease since the first at least medium-term successful liver transplantation in 1967. Clinical studies have played a major part in improving peri- and postoperative therapy in liver transplantation. In this article clinical studies of major impact are presented. Main topics are studies dealing with immunosuppressants, improvements in surgical techniques, viral infections and tumor diseases. Controlled randomized multicentric studies are rare; most of the studies are unicentric. Further studies in the fields of reducing side effects of immunosuppression, the introduction of monoclonal antibodies and improvement of the therapy of viral hepatitis would be helpful. These studies should be controlled, randomized and multicentric.

Photophysics and photochemistry of photodynamic therapy: fundamental aspects.

Photodynamic therapy (PDT) is a treatment modality for cancer and various other diseases. The clinical protocol covers the illumination of target cells (or tissue), which have been loaded with a photoactive drug (photosensitizer). In this review we describe the photophysical and primary photochemical processes that occur during PDT. Interaction of light with tissue results in attenuation of the incident light energy due to reflectance, absorption, scattering, and refraction. Refraction and reflection are reduced by perpendicular light application, whereas absorption can be minimized by the choice of a photosensitizer that absorbs in the far red region of the electromagnetic spectrum. Interaction of light and the photosensitizer can result in degradation, modification or relocalization of the drug, which differently affect the effectiveness of PDT. Photodynamic therapy itself, however, employs the light-induced chemical reactions of the activated photosensitizer (triplet state), resulting in the production of various reactive oxygen species, amongst them singlet oxygen as the primary photochemical product. Based on these considerations, the properties of an ideal photosensitizer for PDT are discussed. According to the clinical experience with PDT, it is proposed that the innovative concept of PDT is most successfully implemented into the mainstream of anticancer therapies by following an application-, i.e. tumor-centered approach with a focus on the actual clinical requirements of the respective tumor type.

[Is 18F-FDG-PET suitable for therapy monitoring after palliative photodynamic therapy of non-resectable hilar cholangiocarcinoma?]. / Ist die.

BACKGROUND: If existing biliary drainage is insufficient, photodynamic therapy (PDT, laser treatment after application of a photosensitizer) is an already established adjunct to palliative therapy for progressing hilar cholangiocarcinoma (Klatskin tumours), since it prolongs survival and improves quality of life. Experimental studies of other tumour entities showed that (18)F-FDG-PET ( (18)F-fluorodeosxyglucose-positron emission tomography) may play a role in monitoring tumour response to PDT. Furthermore, previous studies have revealed a high accuracy of this method for the detection of hilar cholangiocarcinoma. Therefore, the aim of the present study was to investigate the feasibility of (18)F-FDG-PET as a follow-up screening method in patients with hilar cholangiocarcinoma who underwent PDT. PATIENTS AND METHODS: 10 patients were examined by (18)F-FDG-PET before and 4 - 6 weeks after PDT. The following parameters were evaluated: maximum and mean SUV in the tumour, the ratio of maximum SUV in the tumour and mean SUV in the liver, the vital tumour volume, as well as bilirubin and CA 19 - 9 levels. RESULTS: All tumours were detected by (18)F-FDG-PET. Within a period of 4 - 6 weeks after PDT the cholestasis parameter bilirubin decreased significantly. However, SUV-associated parameters did not show a significant change after treatment while the estimated vital tumour volume even increased. DISCUSSION: PDT does not effect a relevant reduction of tumour mass in non-resectable hilar cholangiocarcinoma. However, PDT leads to a significant reduction of cholestasis. If (18)F-FDG-PET is suitable for monitoring the effect of new palliative therapeutic approaches, like brachytherapy, the use of modern chemotherapeuticals, COX-2 and receptor-tyrosine kinase inhibitors, perhaps also in combination with PDT, has to be further investigated.

Characterization of chylomicron remnant clearance by retinyl palmitate label in normal humans.

To characterize chylomicron remnant clearance by the liver, plasma elimination of retinyl palmitate-labeled chylomicron remnants was studied in 18 healthy subjects, ages 21-42 years. Autologous plasma containing retinyl palmitate-labeled chylomicrons and their remnants was injected intravenously, and retinyl palmitate disappearance was measured in serial plasma samples in all subjects and in lipoprotein fractions in 11 subjects. The injected doses (n = 18) ranged from 0.34 to 7.11 mumol retinyl palmitate in d less than or equal to 1.006 g/ml particles with an average molar ratio of 330/1 of retinyl palmitate/apoB-48 (n = 8). The label distributed in the intravascular space and exhibited apparent first order elimination, monoexponential in 6 and biexponential in 12 subjects. The first rapid component k1 (t1/2 18.8 +/- 11.4 min, n = 18) was shown to represent retinyl palmitate in particles of d less than or equal to 1.006 g/ml, i.e., chylomicron remnants, and the second slow component k2 (t1/2 123 +/- 62 min, n = 12) small amounts of retinyl palmitate (11 +/- 7%) injected in d greater than 1.006 g/ml particles (therefore excluded from analysis). Assuming a single-compartment model, initial rates of elimination (= dose x k1) of labeled chylomicron remnants obeyed (P = 0.06) Michaelis-Menten saturation kinetics: Km was 921 +/- 305 nmol retinyl palmitate label and Vmax 124 +/- 14 nmol/min corresponding to 0.88 nM apoB-48 for Km and 0.25 x 10(-3) nmol apoB-48.min-1.g-1 liver for Vmax. Their elimination was limited neither by the injected triglyceride dose nor theoretically by the liver blood flow. After the intake of 70 g of fat (cream) containing retinyl palmitate, the plasma retinyl palmitate concentration exceeded the estimated saturation concentration for 7 h. In conclusion, physiological chylomicron remnant catabolism by the liver appears to be saturable by ordinary lipid intake in healthy humans.

Plasma clearance of chylomicrons labeled with retinyl palmitate in healthy human subjects.

To estimate hepatic uptake of chylomicron remnants in humans, chylomicrons and intestinal very low density lipoproteins (VLDL) were endogenously labeled with retinyl esters, harvested by plasmapheresis, and pulse-injected into the donor 44 hr after plasmapheresis. Plasma decay of retinyl palmitate was measured in eight healthy volunteers. Retinyl palmitate plasma disappearance obeyed an apparent first order function in seven studies and, in one study, a biexponential function with the second, slow exponential accounting for only 13% of the retinyl palmitate plasma decay. The mean fractional removal of rate was 0.037 +/- 0.037 min-1 (mean +/- SD) in a one-compartment model. The apparent volume of distribution, Vd, was 109 +/- 25% of the estimated plasma volume. Plasma clearance of retinyl palmitate was 130 +/- 97 ml/min calculated as Vd x Ke. Mean T 1/2 was 29 +/- 16 min. Both in vitro and in vivo the retinyl palmitate remained largely within chylomicrons and intestinal VLDL. Only 4.3% was transferred from chylomicrons to other lipoprotein classes during in vitro incubation for 5 hr. After plasma was stored for 42 hr, 5% was transferred to higher density lipoproteins. During 12 hr after a test meal containing retinyl palmitate, only 6.4 +/- 1.5% of the retinyl palmitate absorbed was found in the LDL fraction and 3.1 +/- 3.8% in the d 1.063 g/ml lipoproteins. We conclude that retinyl palmitate is a useful marker for chylomicrons and their remnants in humans and that the plasma clearance of retinyl palmitate-labeled chylomicrons is probably an estimate of chylomicron remnant plasma clearance in man.