Antiviral activity of beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine in woodchucks chronically infected with woodchuck hepatitis virus

The L-nucleoside analog beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine (beta-L-Fd4C) was first shown to exhibit potent activity against hepatitis B virus (HBV) in tissue culture and then to significantly inhibit viral spread during acute infection in the duck HBV model (F. Le Guerhier et al., Antimicrob. Agents Chemother. 44:111-122, 2000). We have therefore examined its antiviral activity in a mammalian model of chronic HBV infection, the woodchuck chronically infected with woodchuck hepatitis virus (WHV). Side-by-side comparison of beta-L-Fd4C and lamivudine administered intraperitoneally during short-term and long-term protocols demonstrated a more profound inhibition of viremia in beta-L-Fd4C-treated groups. Moreover, beta-L-Fd4C induced a marked inhibition of intrahepatic viral DNA synthesis compared with that induced by lamivudine. Nevertheless, covalently closed circular (CCC) DNA persistence explained the lack of clearance of infected hepatocytes expressing viral antigens and the relapse of WHV replication after drug withdrawal. Liver histology showed a decrease in the inflammatory activity of chronic hepatitis in woodchucks receiving beta-L-Fd4C. An electron microscopy study showed the absence of ultrastructural changes of hepatic mitochondria, biliary canaliculi, and bile ducts. However, a loss of weight was observed in all animals, whatever the treatment, as was a transient skin pigmentation in all woodchucks during beta-L-Fd4C treatment. There was no evidence that lamivudine or beta-L-Fd4C could prevent the development of hepatocellular carcinoma with the protocols used. These results indicate that beta-L-Fd4C exhibits a more potent antiviral effect than lamivudine in the WHV model but was not able to eradicate CCC DNA and infected cells from the liver at the dosage and with the protocol used.

High incidence of hepatitis B infections among chronic hepatitis cases of unknown aetiology

BACKGROUND/AIMS

In approximately 5% of chronic liver disease cases, no aetiology can be identified. We selected sera from 50 patients with chronic hepatitis of unknown aetiology who were enrolled in this follow-up study whose aim is to gain insight into the possible role of viruses and to define potential clinical outcomes.

METHODS

Patients' sera were screened with highly sensitive polymerase chain reaction assays for hepatitis B (HBV), C, D, and G viruses and TT virus. Sera were also retested for antibodies against the core antigen of HBV.

RESULTS

Surprisingly, HBV DNA was detected in both serum and liver in 15/50 (30%) patients. Immunostaining for HBV antigens on biopsies from patients positive for HBV DNA showed HBcAg and/or HBsAg expression at low levels in 9/15 samples. Eleven of the fifteen patients were anti-HBc positive. With one exception, all patients carried HBV genomes at low levels (10(4) copies/ml or less). Histological signs of chronic liver disease were observed in all patients.

CONCLUSION

Unrecognised HBV infections may account for a high proportion of chronic hepatitis cases of unknown aetiology. Improved HBV detection tests, which appear mandatory for the diagnosis and management of non-A non-E hepatitis as well as for improved safety of transfusions and transplantations are needed.

Rapid detection of genotypes and mutations in the pre-core promoter and the pre-core region of hepatitis B virus genome: correlation with viral persistence and disease severity

BACKGROUND/AIMS

We aimed to clarify the clinical relevance of hepatitis B virus pre-core mutant detection in patients with chronic hepatitis B using a newly developed assay.

METHODS

Viral genotypes and pre-core mutations were studied in relation to viral persistence and liver disease severity using INNO-LiPA methodology. The study group included 151 patients with chronic hepatitis B, 85 positive for HBeAg (group I) and 66 positive for anti-HBe (group II).

RESULTS

The prevalence of viral genotypes in group I was: 64% A, 1% B, 15% C, 19% D, 0% E, 0% F and in group II: 39% A, 0% B, 2% C, 56% D, 2% E, 2% F (p<0.001). The prevalence of mutations at pre-core codon 28 (M2) was lower in group I (5%) than in group II (64%) (p<0.001). The prevalence of pre-core promoter mutations was also lower in group I (21%) than in group II (61%) (p<0.001). M2 mutations were more frequently detected in genotype D than in genotype A (p<0.001), while the other mutations were not influenced by viral genotype. Serum HBV DNA levels were significantly lower in group II versus group I (p<0.001), and in patients with any of the pre-core mutations versus wild-type sequence (p<0.01). Although cirrhosis was more frequent in group II (37%) versus group I (22%) and in patients with either one of the pre-core mutation (31%) versus wild-type sequence (25%), there was no statistical difference in liver severity assessed by ALT levels and Knodell score.

CONCLUSION

Pre-core mutants, whose molecular pattern is strongly dependent on viral genotypes, are associated with viral persistence in anti-HBe positive patients with ongoing chronic hepatitis B. The availability of this rapid assay should allow a precise monitoring of viral pre-core mutants during the course of chronic hepatitis B.

Liver injury due to tetrabamate (Atrium): an analysis of 11 cases

BACKGROUND

Tetrabamate (Atriums), widely used in the treatment of tremor and ethanol-withdrawal symptoms, has been incriminated as a potential cause of reversible acute hepatitis.

OBJECTIVE

We report here on 11 patients who experienced tetrabamate-related liver injury, in order to evaluate their clinical, histopathological and evolutive features.

PATIENTS AND METHODS

Between 1987 and 1998, 34 cases of tetrabamate-associated acute hepatitis were spontaneously reported to the regional pharmacovigilance center of Lyon. Eleven cases were considered probably to be drug-induced.

RESULTS

There were three males and eight females aged 31-82 years (mean, 57 years). The duration of treatment ranged from 33 to 206 days, and indication for treatment was depressive disorders, tremor or prevention of alcohol withdrawal symptoms. Clinical symptoms were asthenia (n = 9), jaundice (n = 3) and/or diffuse rash (n = 3). The pattern of liver injury was cytolytic (n = 10) or cholestatic (n = 1). Three patients presented biological features of hepatic failure. A percutaneous liver biopsy was performed in six patients. Histological examination of the liver specimen showed a large spectrum of lesions: massive hepatocellular necrosis (n = 1), centrilobular and nonconfluent hepatocyte necrosis (n = 2), intracellular cholestasis (n = 3), and granulomatous hepatitis (n = 1). Tetrabamate was discontinued in all patients. In seven patients, a complete recovery was observed 3 weeks to 3 months after drug withdrawal. Two patients, despite a rapid improvement of liver function tests, died from unrelated causes. The remaining two patients died from irreversible hepatic failure.

CONCLUSIONS

Our data strongly suggest that tetrabamate may induce acute liver injury, which may eventually result in life-threatening liver failure.

Increased expression of growth hormone and prolactin receptors in hepatocellular carcinomas

The liver is an essential target tissue for growth hormone (GH) and prolactin (PRL). The aim of this study was to determine the in situ expression of growth hormone receptor (GHR) and prolactin receptor (PRLR) in hepatocellular carcinomas and to compare the results with normal liver. For this purpose, in situ hybridization (ISH) and immunohistochemical techniques were performed and several tests were conducted to validate the results. By radioactive ISH, all the hepatocellular carcinomas studied showed labeling for GHR and PRLR mRNAs. Relative expression levels, determined by computer-assisted microdensity, were higher in hepatocellular carcinomas than in normal liver. Immunohistochemistry led us to confirm the constant expression of both receptor proteins in hepatocellular carcinomas and normal liver and to demonstrate their localization not only in the cytoplasm but also in the nucleus. These results confirm that the liver is a major GH and PRL target tissue and suggest that in hepatocellular carcinomas the proliferative effects of these hormones may be increased by a higher expression of their receptors.

Gastric helicobacters in cats

The types of helicobacter which are found in the stomachs of carnivorous pets, especially cats, have been traditionally referred to as 'gastric helicobacter-like organisms' (GHLOs). These are microaerophilic, Gram-negative, spiral bacteria with multiple terminal flagellae and are endowed with high-level urease activity which allows them to survive in an acidic environment. Certain species have one or more periplasmic fibrils. The two GHLOs most commonly found in cats are Helicobacter felis and a species related to H heilmannii which was recently cultured from dogs. All phenotypic and genotypic (16S RNA gene sequences) evidence suggests that both of these bacteria belong in the genus Helicobacter. Whether or not helicobacters can be transmitted to humans from carnivorous pets is controversial but the recent discovery of H pylori -infected cats may be evidence of an animal reservoir for this pathogen. Although the role of H pylori in inducing antral gastritis and perpetuating pyloric ulcers in humans is well established, whether or not Helicobacter spp are causally involved in any feline gastric inflammatory conditions is unknown.

Characterization of the antiviral effect of 2',3'-dideoxy-2', 3'-didehydro-beta-L-5-fluorocytidine in the duck hepatitis B virus infection model

A novel L-nucleoside analog of deoxycytidine, 2',3'-dideoxy-2', 3'-didehydro-beta-L-5-fluorocytidine (beta-L-Fd4C), was recently shown to strongly inhibit hepatitis B virus (HBV) replication in the 2.2.15 cell line. Therefore, its antiviral activity was evaluated in the duck HBV (DHBV) infection model. Using a cell-free system for the expression of the DHBV polymerase, beta-L-Fd4C-TP exhibited a concentration-dependent inhibition of dCTP incorporation into viral minus-strand DNA with a 50% inhibitory concentration of 0.2 microM which was lower than that of other tested deoxycytidine analogs, i.e. , lamivudine-TP, ddC-TP, and beta-L-FddC-TP. Further analysis showed that beta-L-Fd4C-TP is likely to be a competitive inhibitor of dCTP incorporation and to cause premature DNA chain termination. In primary duck hepatocyte cultures infected in vitro, beta-L-Fd4C administration exhibited a long-lasting inhibitory effect on viral DNA synthesis but could not clear viral covalently closed circular DNA (CCC DNA). Results of short-term antiviral treatment in experimentally infected ducklings showed that beta-L-Fd4C exhibited the most potent antiviral effect, followed by beta-L-FddC, lamivudine, and ddC. Longer administration of beta-L-Fd4C induced a sustained suppression of viremia (>95% of controls) and of viral DNA synthesis within the liver. However, the persistence of trace amounts of viral CCC DNA detected only by PCR was associated with a recurrence of viral replication after drug withdrawal. In parallel, beta-L-Fd4C treatment suppressed viral antigen expression within the liver and decreased intrahepatic inflammation and was not associated with any sign of toxicity. Our data, therefore, demonstrate that in the duck model of HBV infection, beta-L-Fd4C is a potent inhibitor of DHBV reverse transcriptase activity in vitro and suppresses viral replication in the liver in vivo.

Recurrence of hepatocellular carcinoma as a mixed hepatoblastoma after liver transplantation

BACKGROUND

Hepatoblastoma is an exceptional cause of primary malignant liver tumour in the adult.

PATIENT

The case is reported of an adult patient transplanted for alcoholic cirrhosis complicated by multifocal hepatocellular carcinoma in whom a recurrence in the form of a mixed hepatoblastoma invading the whole transplanted liver developed three months after liver transplantation.

METHODS

Complete clinical, histopathological, and immunohistochemical data were reviewed.

RESULTS

The recurrent tumour invaded the whole liver. The major component was a mixed hepatoblastoma, with an epithelial component expressing cytokeratin and a mesenchymal component expressing vimentin. The tumour also contained a minor hepatocarcinomatous component expressing alpha fetoprotein. The rapid growth of the tumour prevented any attempt at treatment. Although direct evidence is lacking, the most likely hypothesis to explain the observations is a marked phenotypic change in the initial malignant population at recurrence.

CONCLUSION

This case supports a possible filiation between hepatocellular carcinoma and hepatoblastoma in adults.

Familial occurrence of nodular regenerative hyperplasia of the liver: a report on three families

BACKGROUND/AIMS

Nodular regenerative hyperplasia of the liver is a histological lesion usually associated with systemic diseases, haematological malignancies, or drugs. Its prognosis depends on portal hypertension, which usually is well tolerated and requires medical management only.

PATIENTS

Three unrelated families, in which two sibling adult male patients presented with nodular regenerative hyperplasia of the liver, were studied.

METHODS

Complete clinical charts and liver biopsy specimens were available for all patients. In addition, explanted livers were available for examination for the two transplanted patients.

RESULTS

There was no evidence of any of the various clinical situations known to be associated with nodular regenerative hyperplasia of the liver. Portal hypertension was severe, requiring surgical treatment in two cases. Renal lesions were present in three patients. In two patients, progressive evolution to liver atrophy and hepatic failure, associated with renal failure, led to combined liver and renal transplantation.

CONCLUSIONS

This report describes the existence of familial cases of nodular regenerative hyperplasia of the liver, occurring without underlying or associated systemic disease, characterised by a poor clinical course and often associated with progressive renal failure.

Treatment of hepatitis C virus-related cirrhosis: a randomized, controlled trial of interferon alfa-2b versus no treatment

To examine the effects of interferon (IFN) therapy on clinical, biochemical, and histological features in patients with compensated hepatitis C virus (HCV)-related cirrhosis, we have conducted a randomized, controlled trial of IFN therapy versus observation. Eight centers included a total of 99 patients with biopsy-proven cirrhosis. IFN-alpha2b, 3 million units three times per week, or no antiviral therapy was given for 48 weeks. Twenty-three patients dropped out. End-of-treatment biochemical response was not observed in any of the 39 controls but was observed in 6 of the 47 treated patients (P <.02); sustained biochemical response was obtained in only 2 treated patients. Controls and treated patients did not significantly differ with regard to the changes in serum level of albumin, bilirubin, alpha-fetoprotein, in plasma prothrombin, in histological activity, or liver collagen content. During trial or follow-up (160 +/- 57 weeks), hepatocellular carcinoma developed in 9 controls and 5 treated patients (NS); decompensation of cirrhosis occurred in 5 controls and 7 treated patients. Seven controls and 10 treated patients died. In conclusion, in patients with compensated HCV-related cirrhosis, a 48-week course of IFN therapy is safe and is able to induce end-of-treatment biochemical response in a significant proportion of patients. However, a 48-week course of IFN therapy usually fails to achieve sustained response and, within the limit of this study, did not significantly improve the 3-year outcome. Therefore, a longer course of IFN therapy or combination therapy with ribavirin should be evaluated in patients with HCV-related cirrhosis.

Enhanced duck hepatitis B virus gene expression following aflatoxin B1 exposure

Epidemiological studies have suggested synergistic interactions between chronic hepatitis B virus (HBV) infection and aflatoxin B1 (AFB1) exposure in the etiology of hepatocellular carcinoma (HCC), although the molecular mechanisms of their interactions are still not understood. The aim of this study was to use the Pekin duck model to investigate the impact of AFB1 exposure on duck hepatitis B virus (DHBV) replication during the early stages of virus-carcinogen interactions. Six-week-old chronic DHBV-carrier or uninfected ducks were exposed to AFB1 for 5 weeks or treated with dimethylsulfoxide (DMSO) as a control. Animals were observed for 6 to 13 weeks after AFB1 treatment to study the influence of AFB1 exposure on DHBV replication and liver pathologies. Histological analysis showed more marked changes in the livers of AFB1-treated ducks, and these were enhanced by DHBV infection. A significant increase in serum and liver DHBV DNA level was observed in AFB1-treated ducks as compared with DMSO-treated controls. In addition, viral RNAs, in particular the pregenomic RNA that is the template of viral replication, and intrahepatic DHBV DNA replicative intermediates, were significantly increased by AFB1 treatment. Moreover, an overexpression and accumulation of DHBV large envelope (L) protein was observed in the hepatocytes of AFB1-exposed animals. The in vitro study has further confirmed an increase in intracellular viral DNA and in virus release in AFB1-treated primary duck hepatocytes. Taken together, our results indicate that AFB1 exposure leads to an increase in virus gene expression associated with intrahepatic accumulation of DHBV L protein and enhanced liver pathology.

Long-term administration of interferon-alpha in non-responder patients with chronic hepatitis C: follow-up of liver fibrosis over 5 years

In chronic hepatitis C, previous data have shown that short-term treatment with interferon-alpha (IFN-alpha) can reduce collagen deposition in the liver independently of the viral response. The aim of this work was to determine, in non-responder patients, the long-term effect of IFN-alpha on liver fibrosis according to the total administered dose and the fibrotic stage. Fibrosis was investigated on liver biopsies from 24 non-responder patients with chronic hepatitis C retreated with successive courses of IFN-alpha. The degree of liver fibrosis was assessed on three successive biopsies, performed before IFN-alpha treatment and 1 and 5 years later, in 13 and 11 patients, respectively, treated for less (mean: 7.5 months, 313 MU) and more (mean: 21.8 months, 791 MU) than 1 year. For each biopsy, fibrosis was assessed using a histological semiquantitative fibrosis scoring system and by morphometry after picrosirius red staining. Regardless of the dose and duration of IFN-alpha therapy, a slight decrease of fibrosis was observed in patients 5 years after starting treatment. In cirrhotic patients, a short treatment induced an improvement followed by a relapse of fibrosis in 57%, and only 43% of patients showed constant collagen regression over the 5 years of follow-up. On the contrary, after prolonged therapy, a progressive and significant decrease occurred throughout the follow-up period in all patients (P = 0.045). Long-term treatment with IFN-alpha is therefore associated with regression of liver fibrosis, particularly in cirrhotic patients. These promising results need to be confirmed in a larger series of patients.

Clinical evaluation of the branched DNA assay for hepatitis B virus DNA detection in patients with chronic hepatitis B lacking hepatitis B e antigen and treated with interferon-alpha

The aim of this study was to evaluate the Chiron branched DNA (bDNA) assay for detection of serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis B lacking hepatitis B e antigen (HBeAg) and undergoing interferon (IFN) therapy. Results obtained with the bDNA assay were compared with those obtained using the Abbott liquid hybridization (LH) assay and the polymerase chain reaction (PCR). Serial samples (274) from 34 patients were analysed. Analysis of variance results indicated that bDNA values were more significantly correlated than LH values with both PCR positive/negative results (probability of artifact (Prob > F) = 0.7 and 0.09 for LH and bDNA assays, respectively) and presence/absence of precore mutations (Prob > F = 0.21 and 0.001 for LH and bDNA assays, respectively). Both bDNA and LH results correlated highly with alanine aminotransferase (ALT) values (both had Prob > F values of 0.0) while PCR was not correlated with ALT (Prob > F = 0.05). In 26 evaluable patients, a model based on a generalized Knodell score was used to predict response to IFN therapy, as defined by normalization of ALT values during therapy. This model discriminated well between non-responders and responders. The bDNA results correlated well with the generalized Knodell score, while the LH results did not (Prob > F = 0.04 and 0.19 for the bDNA and LH assays, respectively). In conclusion, the bDNA assay appears to be useful for quantification of HBV DNA levels in HBeAg-negative chronic hepatitis as it correlates with biochemical and histological indications of disease severity as well as with response to IFN therapy.

Differential pathogenic effect of two Helicobacter-like organisms in dog gastric mucosa

Two forms of Helicobacter were detected in the gastric mucosa of twelve healthy beagle dogs. According to ultrastructural criteria they could be classified as Helicobacter bizzozeronii-like and Helicobacter felis-like species. In five animals, the light fundic load of Helicobacter bizzozeronii-like did not affect the integrity of the glandular epithelium. In three animals, the heavy bacterial load extended in the lumens of antral glands and coincided with increased intraepithelial lymphoid infiltrate. The heavy bacterial load observed in 4 animals was mixed (Helicobacter bizzozeronii-like and Helicobacter felis-like), fundic and antral, luminal and intracellular. Adherence of Helicobacter felis-like to epithelial cells and intracellular penetration were responsible for focal necrosis, and glandular atrophy might be observed. Helicobacter bizzozeronii-like thus appeared non pathogenic in beagle dogs, even when the heavy bacterial load extended to the antrum. By contrast, Helicobacter felis-like showed a constant pathogenic effect linked to its properties of adhesion and penetration into epithelial cells. A wider comparative study in humans and domestic carnivorous will determine if the latter may play a role of reservoir-host for pathogenic bacteria.

Liver fibrosis in unisexual murine Schistosomiasis: quantitative study and morphological changes in mice with chronic infection

The main complication of Schistosomiasis is the development of liver fibrosis as a result of periovular granuloma in portal tract. This study was undertaken to evaluate the role of the worms in the liver, using the unisexual murine schistosomiasis model. Hepatic fibrosis and histopathological lesions were sequentially followed for 65 weeks in mice experimentally infected with male Schistosoma mansoni. Morphological study revealed that, from the 25th week post-infection, a diffuse fibrosis affected the main branches of the portal vascular system following the host inflammatory reaction, associated with the proliferation of myofibroblasts in situ. Quantitative methods confirmed that an increase of fibrotic deposit occurred during chronic unisexual infection from 25 to 50 weeks post-infection, as compared to controls (35.06 +/- 3.55% versus 27.41 +/- 2.56%) suggesting that antigenic substances secreted by adult schistosomes, in the absence of any eggs, might initiate periportal and perisinusoidal fibrous reaction. The cytokine production and the evolution of inflammation towards fibrosis involves stellate cells and myofibroblasts stimulation. This fibrotic process consequently traduces a reparative phenomenon of the liver.

[Favorable course of hepatitis B virus reactivation with hepatocellular insufficiency by a treatment combining corticoids, foscarnet and ganciclovir]

Reactivation of hepatitis B virus replication is a rare event during the natural history of chronic hepatitis B. However, the clinical presentation may be severe and an effective therapeutic protocol must be established. We report a case of spontaneous reactivation of hepatitis B virus infection with liver failure. For the moment, no medical treatment has been defined in this situation. A combination of corticosteroids and antiviral drugs (foscarnet and ganciclovir) resulted in clinical and biological recovery, and HBV elimination. If the efficacy of this combined treatment is confirmed in a larger population, this new physiopathological approach should be considered whenever life threatening liver failure occurs.

Ribavirin monotherapy in patients with chronic hepatitis C: a retrospective study of 95 patients

Ribavirin is a purine nucleoside that inhibits the replication of a variety of RNA viruses and was shown to have a transient efficacy in chronic hepatitis C during short-term therapy. We have analysed retrospectively its efficacy in 95 patients with liver biopsy-proven chronic hepatitis C. Patients received oral ribavirin (600-1200 mg daily) for a mean duration of 11 months. Alanine aminotransferase (ALT) levels returned to normal values in 38 patients (40%) and decreased by more than 50% in 20 other patients (21%). HCV RNA clearance from serum was observed in seven patients (8%). The biochemical response rate was higher in patients with chronic hepatitis (54%) than in those with cirrhosis (24%) (P = 0.003). Clearance of HCV RNA was observed in 10% of the patients with chronic hepatitis vs 4% of the patients with cirrhosis. In non-responders to interferon (IFN) therapy, ALT levels returned to normal values in 11 (26%) and HCV RNA became negative in one (2%), as compared to 48% and 3%, respectively, in those contraindicated for IFN. In 17 patients in whom paired liver biopsy specimens were available, the histology activity index (HAI) improved in 12. Therapy was generally well tolerated although 11 patients had to stop therapy because of side-effects, which were more common in cirrhotic patients. In conclusion, our results suggest that long-term administration of ribavirin is well tolerated and may be beneficial in controlling the progression of chronic hepatitis C. This may represent an alternative therapy in patients who have contraindications for interferon therapy or as a palliative approach in non-responders to IFN.

Inhibitory effect of 2'-fluoro-5-methyl-beta-L-arabinofuranosyl-uracil on duck hepatitis B virus replication

The antiviral activity of 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil (L-FMAU), a novel L-nucleoside analog of thymidine known to be an inhibitor of hepatitis B virus (HBV) replication in hepatoma cells (2.2.1.5 cell line), was evaluated in the duck HBV (DHBV) model. Short-term oral administration (5 days) of L-FMAU (40 mg/kg of body weight/day) to experimentally infected ducklings induced a significant decrease in the level of viremia. This antiviral effect was sustained in animals when therapy was prolonged for 8 days. The histological study showed no evidence of liver toxicity in the L-FMAU-treated group. By contrast, microvesicular steatosis was found in the livers of dideoxycytidine-treated animals. L-FMAU administration in primary duck hepatocyte cultures infected with DHBV induced a dose-dependent inhibition of both virion release in culture supernatants and intracellular viral DNA synthesis, without clearance of viral covalently closed circular DNA. By using a cell-free system for the expression of an enzymatically active DHBV reverse transcriptase, it was shown that L-FMAU triphosphate exhibits an inhibitory effect on the incorporation of dAMP in the viral DNA primer. Thus, our data demonstrate that L-FMAU inhibits DHBV replication in vitro and in vivo. Long-term administration of L-FMAU for the eradication of viral infection in animal models of HBV infection should be evaluated.

[Efficacy of interferon alpha in primary prevention of preneoplastic lesions in a transgenic murine model of hepatocellular carcinoma related to the interaction between woodchuck hepatitis viruses and c-myc oncogene]

OBJECTIVES

C-myc oncogene overexpression by near insertion of hepatitis B virus is important in woodchuck hepatocarcinogenesis. This DNA fragment was transferred in mice who developed hepatocellular carcinoma via preneoplastic lesions. In the present study, we tested the preventive effect of alpha interferon on the incidence of hepatocyte dysplasia.

METHODS

Human recombinant alpha interferon hybrid B/D was continuously administered at increasing doses (0 to 10,000 IU/g) in a transgenic mouse model. One cohort was treated from day 21 to day 80. A histological liver examination was performed and the transgene expression was assessed by hybridization with or without previous genic amplification, and by indirect immunofluorescence.

RESULTS

At day 15, histological liver examination was normal. Interferon treatment decreased the expression of viral sequences, but not of c-myc. At day 80, interferon treatment resulted in a reduction of the incidence and severity of dysplasic lesions, and a marked decrease in c-myc overexpression.

CONCLUSION

In this transgenic mouse model, alpha interferon treatment decreased the incidence and severity of precancerous lesions, due to a reduction in c-myc overexpression. This prophylaxis could be of interest in human hepatocarcinogenesis where c-myc overexpression is frequent.

[Para-aortic paraganglioma found by arteriography. Apropos of a case and review of the literature]

A 53 years old man had an angiography for suspected renovascular hypertension (arteritis, renal insufficiency, duplex scanning). It showed a narrow right renal artery streched by a 45 mm mass arising from the adrenal. The computed tomography showed the tumor and the nuclear magnetic resonance imaging indicated a pheochromocytoma. The patient had no complain of headaches, palpitations or sweating. Biochemistry was normal except for a slight serum creatinin elevation and a non significant urinary noradrenaline level. A diagnostic of non functioning pheochromocytoma was made. The therapeutics consisted in a surgical ablation of the tumor and the right kidney (non functioning) and the patient became normotensive thereafter without treatment. The histologic feature was an aortico-sympathetic paraganglia, the adrenal was normal. Paraganglias are arising from the paraganglion system including chemodectoma and glomus jugulare tumor. Non functioning retroperitoneal paraganglias are uncommon: less than 50 in the literature between 1902 and 1992.

Pilot study of the combination of interferon alfa and ribavirin as therapy of recurrent hepatitis C after liver transplantation

Recurrent hepatitis C virus (HCV) in liver transplant patients is a major cause of graft loss, liver failure, and need for retransplantation. The results available to date with the use of interferon alfa (IFN-alpha) in the treatment of recurrent HCV in liver transplant patients have been disappointing. The aim of this study was to evaluate the efficacy and clinical utility of post-transplant combination therapy with IFNalpha2b (3 million units 3 times weekly) and oral ribavirin (1,200 mg/d) for a duration of 6 months, followed by maintenance with ribavirin alone for an additional 6 months. Twenty-one liver transplant recipients with recurrent hepatitis C infection (HCV-RNA-positive; active hepatitis without rejection on biopsy) were enrolled in this study. Pretreatment serum alanine transaminase (ALT) levels were at least two times the upper limit of normal. Before treatment, all patients were HCV-RNA-positive and mean HCV-RNA titers were 125 million genome-equivalents/mL. Mean pretreatment histological score was 6.3 +/- 2. After 6 months of combination therapy, all 21 patients had normal ALTs. Ten patients (48%) cleared HCV-RNA from their serum, as assessed by polymerase chain reaction (PCR), and HCV-RNA levels decreased significantly in the others (P = .0001). Improvement in histological score was seen in all patients after combination therapy (P = .0013). During maintenance ribavirin monotherapy, ALT remained normal in all but 1 of the 18 patients who tolerated therapy. HCV-RNA reappeared in 5 patients, but HCV-RNA levels did not return to pretreatment levels (P = .0004). Comparison of pretreatment and postribavirin monotherapy liver biopsies revealed improvement in all but 1 of the 18 patients who tolerated ribavirin (P = .0002). Side effects were restricted to anemia, which necessitated cessation of ribavirin therapy in 3 patients. No patient experienced graft rejection during the study period. These results are significantly better than those reported with IFN-alpha monotherapy. Most importantly, there was a complete absence of graft rejection. These results suggest that the combination of IFN-alpha and ribavirin is effective in reducing HCV-RNA levels and ameliorating hepatocellular injury in recurrent HCV after liver transplantation, and that maintenance therapy with ribavirin monotherapy can maintain the biochemical and histological response.