Acid-Base Balance during Continuous Veno-Venous Hemofiltration: The Impact of Severe Hepatic Failure

Background

Continuous renal replacement therapy (CRRT) affects acid-base balance but the influence of severe hepatic failure (SHF) on this effect is unknown.

Aim

To assess the effect of SHF on acid-base balance in patients receiving CVVH.

Design

Retrospective laboratory investigation.

Subjects

Forty patients with SHF and acute renal failure (ARF) treated with CVVH and 42 critically ill patients with severe ARF but no liver disease also treated with CVVH (controls).

Intervention

Retrieval of clinical and laboratory data from prospective unit and laboratory databases.

Methods

Quantitative acid-base status assessment using the Stewart-Figge methodology. Comparison of findings between the two groups.

Results

Although CVVH had a major effect on acid base balance in both groups, patients with SHF had a higher mean lactate concentrations (4.8 vs. 3.1 mmol/L; p<0.0005), a greater base deficit compared to controls (-1 vs. 4.1 mEq/L; p<0.0001) and a lower PaCO2 tension (36.8 vs. 42.5 mmHg; p<0.0001), despite the use of bicarbonate replacement fluid. The acidifying effect of hyperlactatemia was slightly worsened by an increased strong ion gap (9.3 vs. 4.9 mEq/L; p<0.0001). It was, however, attenuated by an increased strong ion difference apparent (SIDa) (43.6 vs. 41.9 mEq/L; p<0.05) secondary to hypochloremia (96 vs. 100 mmol/L; p<0.0001) and by hypoalbuminemia, although hypoalbuminemia in SHF patients (26 vs. 23; p<0.005) was less pronounced than in controls.

Conclusion

The use of CVVH does not fully correct the independent acidifying effect of liver failure on acid-base status. Increased lactate and strong ion gap values maintain a persistent base deficit despite the alkalinizing effects of hypoalbuminemia and hypochloremia. The correction of acidosis in SHF patients may require more intensive CVVH.

Acid-base Balance in Combined Severe Hepatic and Renal Failure: A Quantitative Analysis

Background

Severe hepatic failure (SHF) commonly leads to major changes in acid-base balance status. However, the direct effects of liver failure per se on acid base balance are poorly understood because this condition is usually associated with acute renal failure (ARF).

Aim

To assess the effect of SHF on acid-base balance.

Design

Retrospective laboratory investigation.

Subjects

Thirty-seven critically ill patients with SHF complicated by ARF, and 42 patients with severe ARF without liver failure prior to renal replacement therapy.

Intervention

Retrieval of clinical and laboratory data from prospective unit and laboratory databases.

Methods

Quantitative acid-base assessment using Stewart-Figge methodology. Comparison of findings between the two groups. Comparison of demographic and clinical features.

Results

Patients with combined SHF and ARF were younger and had significantly higher mean bilirubin, ALT and INR levels (p<0.0001). Their mean lactate concentration was higher (6.4 vs. 2.1 mmol/L; p<0.0001) leading to a greater anion gap (25.8 vs. 16.1 mmol/L; p<0.0001). The ionized calcium concentration (1.00 vs. 1.15 mmol/L; p<0.0001) was lower but the strong ion difference apparent (SIDa) was greater (42.0 vs. 38.0 mEq/L; p<0.005) due to hypochloremia. The albumin concentration was low but higher than in control patients (28 vs. 24 g/L; p<0.01) and the calculated strong ion gap (SIG) was greater (12.6 vs. 9.3 mEq/L; p<0.01). The base excess was similar to controls and the pH was preserved in the near normal range by marked hypocapnea.

Conclusions

Combined SHF and ARF is a syndrome with unique acid-base changes due mostly to lactic metabolic acidosis and, in smaller part, to the accumulation of unmeasured anions. This acidosis, like that of ARF, is attenuated by hypoalbuminemia, by a unique preservation of the SIDa due to hypochloremia, and by marked hypocapnea.

Hepatitis C recurrence: the Achilles heel of liver transplantation

Hepatitis C virus (HCV) infection is the most common indication for liver transplantation worldwide; however, recurrence post transplant is almost universal and follows an accelerated course. Around 30% of patients develop aggressive HCV recurrence, leading to rapid fibrosis progression (RFP) and culminating in liver failure and either death or retransplantation. Despite many advances in our knowledge of clinical risks for HCV RFP, we are still unable to accurately predict those most at risk of adverse outcomes, and no clear consensus exists on the best approach to management. This review presents a critical overview of clinical factors shown to influence the course of HCV recurrence post transplant, with particular focus on recent data identifying the important role of metabolic factors, such as insulin resistance, in HCV recurrence. Emerging data for genetic markers of HCV recurrence and their usefulness for predicting adverse outcomes will also be explored.

Identifying the superior measure of rapid fibrosis for predicting premature cirrhosis after liver transplantation for hepatitis C

BACKGROUND

Hepatitis C virus (HCV) recurrence post liver transplant is universal, with a subgroup of patients developing rapid hepatic fibrosis. Various clinical definitions of rapid fibrosis (RF) have been used to identify risks for rapid progression, but their comparability and efficacy at predicting adverse outcomes has not been determined.

METHODS

Retrospective data analysis was conducted on 100 adult patients with HCV who underwent liver transplantation at a single center. We measured year 1 fibrosis progression (RF defined as METAVIR F score ≥ 1 at 1-year liver biopsy), time to METAVIR F2-stage fibrosis, and fibrosis rate (calculated using liver biopsies graded by METAVIR scoring F0-4; fibrosis rate = fibrosis stage/year post transplant). RF was defined as ≥ 0.5 units/year.

RESULTS

Multivariate analysis revealed that donor age and peak HCV viral load were significant risks for RF, when fibrosis rate was used to define RF. Advanced donor age was a risk for rapid progression to F2-stage fibrosis, whereas genotype 2 or 3 HCV infection was protective. Fibrosis rate had the strongest correlation with time to cirrhosis development (P < 0.0001, r = -0.76) and was the most accurate predictor of rapid graft cirrhosis (P < 0.0001, area under the curve 0.979, sensitivity 100%, specificity 94%).

CONCLUSION

Different measures of RF progression identify different risks for RF and are not directly comparable. Fibrosis rate was the most accurate predictor of rapid graft cirrhosis.

Toll-like receptor 3 and 7/8 function is impaired in hepatitis C rapid fibrosis progression post-liver transplantation

Recurrence of hepatitis C (HCV) postliver transplant is universal, with a subgroup developing rapid hepatic fibrosis. Toll-like receptors (TLRs) are critical to innate antiviral responses and HCV alters TLR function to evade immune clearance. Whether TLRs play a role in rapid HCV recurrence posttransplant is unknown. We stimulated peripheral blood mononuclear cells (PBMCs) from 70 patients with HCV postliver transplant with TLR subclass-specific ligands and measured cytokine production, TLR expression and NK cell function. Rate of fibrosis progression was calculated using posttransplant liver biopsies graded by Metavir scoring (F0-4; R=fibrosis stage/year posttransplant; rapid fibrosis defined as >0.4 units/year). Thirty of 70 (43%) patients had rapid fibrosis progression. PBMCs from HCV rapid-fibrosers produced less IFNα with TLR7/8 stimulation (p=0.039), less IL-6 at baseline (p=0.027) and with TLR3 stimulation (p=0.008) and had lower TLR3-mediated monocyte IL-6 production (p=0.028) compared with HCV slow fibrosers. TLR7/8-mediated NKCD56 dim cell secretion of IFNγ was impaired in HCV rapid fibrosis (p=0.006) independently of IFNα secretion and TLR7/8 expression, while cytotoxicity remained preserved. Impaired TLR3 and TLR7/8-mediated cytokine responses may contribute to aggressive HCV recurrence postliver transplantation through impaired immune control of HCV and subsequent activation of fibrogenesis.

Toll-like receptor 3 and 7/8 function is impaired in hepatitis C rapid fibrosis progression post-liver transplantation

Recurrence of hepatitis C (HCV) postliver transplant is universal, with a subgroup developing rapid hepatic fibrosis. Toll-like receptors (TLRs) are critical to innate antiviral responses and HCV alters TLR function to evade immune clearance. Whether TLRs play a role in rapid HCV recurrence posttransplant is unknown. We stimulated peripheral blood mononuclear cells (PBMCs) from 70 patients with HCV postliver transplant with TLR subclass-specific ligands and measured cytokine production, TLR expression and NK cell function. Rate of fibrosis progression was calculated using posttransplant liver biopsies graded by Metavir scoring (F0-4; R=fibrosis stage/year posttransplant; rapid fibrosis defined as >0.4 units/year). Thirty of 70 (43%) patients had rapid fibrosis progression. PBMCs from HCV rapid-fibrosers produced less IFNα with TLR7/8 stimulation (p=0.039), less IL-6 at baseline (p=0.027) and with TLR3 stimulation (p=0.008) and had lower TLR3-mediated monocyte IL-6 production (p=0.028) compared with HCV slow fibrosers. TLR7/8-mediated NKCD56 dim cell secretion of IFNγ was impaired in HCV rapid fibrosis (p=0.006) independently of IFNα secretion and TLR7/8 expression, while cytotoxicity remained preserved. Impaired TLR3 and TLR7/8-mediated cytokine responses may contribute to aggressive HCV recurrence postliver transplantation through impaired immune control of HCV and subsequent activation of fibrogenesis.

Viral factors influencing the outcome of human cytomegalovirus infection in liver transplant recipients

BACKGROUND

Cytomegalovirus (CMV) remains the leading viral cause of disease following orthotopic liver transplantation (OLT) despite the availability of antiviral agents for prophylaxis and therapy.

OBJECTIVE

Examine the viral factors that influence the outcome of CMV infection following valganciclovir prophylaxis or laboratory-guided preemptive therapy in OLT recipients.

STUDY DESIGN

The value of valganciclovir prophylaxis and laboratory-guided preemptive therapy for the prevention of CMV infection and disease was observed in 64 OLT recipients. Prophylaxis was given to all CMV seronegative recipients receiving a liver from a seropositive donor (D+R-; n=15), and all other recipients were randomised to receive either prophylaxis (n=24) or laboratory-guided preemptive therapy (n=25). Recipients were monitored for CMV DNAemia, viral load, emergence of antiviral resistant strains and co-infections.

RESULTS

CMV end-organ disease and antiviral resistant strains only occurred in D+R- recipients despite the use of prophylaxis in these patients. The D+R- recipients commencing prophylaxis immediately following transplantation had better outcomes compared to those for whom prophylaxis was delayed due to renal impairment. Prophylaxis reduced the incidence of CMV DNAemia, persistent infection, and high viral loads for CMV seropositive (D-R+and D+R+) recipients, but laboratory-guided preemptive therapy effectively controlled CMV infection and prevented disease in these OLT recipients.

CONCLUSION

Delaying the commencement of valganciclovir prophylaxis may be associated with worse outcomes for high-risk OLT recipients. Laboratory-guided pre-emptive therapy remains an alternative approach for seropositive recipients at lower risk of CMV disease.

Kidney failure associated with liver transplantation or liver failure: the impact of continuous veno-venous hemofiltration

BACKGROUND AND AIMS

The short-term outcome of critically ill patients with kidney failure combined with severe liver failure or orthotopic liver transplantation (OLTx) is poor. We sought to test the hypothesis that, with the exclusive use of continuous veno-venous hemofilration (CVVH) with minimal heparin-anticoagulation, the short and long-term outcomes of these patients would be improved.

PATIENTS

Sixty-six consecutive patients with combined liver and kidney failure

SETTING

Intensive Care Unit of tertiary hospital

DESIGN

Retrospective interrogation of prospectively collected databases

INTERVENTION

Treatment of all patients with continuous veno-venous hemofiltration (CVVH) by protocol with 2L/h of ultrafiltration rate and minimal use of circuit heparinization. Retrieval of specific information on demographic, clinical, therapeutic and outcome details.

MEASUREMENTS AND MAIN RESULTS

From July 1995 to April 2004, 66 patients with combined liver and renal failure received continuous veno-venous hemofiltration (CVVH). Of these, 26 received liver transplantation and 40 did not. There were no significant differences in age, APACHE II score, bilirubin, ALT, INR or albumin on admission. The average duration of CVVH was 9.5 days for OLTx patients and 5 days for non-transplanted patients (p=0.013). Heparin anticoagulation was used in only 12% of OLTx patients and 20% of non-transplanted patients. ICU mortality was 15% in OLTx patients and 63% in non-transplanted patients (p<0.0005); hospital mortality was 23% compared to 70% (p<0. 001). Mean survival time at follow up was 1,120 days compared to 358 days (p<0.0001).

CONCLUSIONS

ARF associated with OLTx has a much better outcome than ARF without OLTx. Furthermore, management based on a conservative anticoagulation policy and CVVH as the exclusive form of renal support was associated with the best ICU, hospital and long term survival reported so far.

Clinical emergence of entecavir-resistant hepatitis B virus requires additional substitutions in virus already resistant to Lamivudine

Entecavir (ETV) exhibits potent antiviral activity in patients chronically infected with wild-type or lamivudine (3TC)-resistant (3TC(r)) hepatitis B virus (HBV). Among the patients treated in phase II ETV clinical trials, two patients for whom previous therapies had failed exhibited virologic breakthrough while on ETV. Isolates from these patients (arbitrarily designated patients A and B) were analyzed genotypically for emergent substitutions in HBV reverse transcriptase (RT) and phenotypically for reduced susceptibility in cultures and in HBV polymerase assays. After 54 weeks of 3TC therapy, patient A (AI463901-A) received 0.5 mg of ETV for 52 weeks followed by a combination of ETV and 100 mg of 3TC for 89 weeks. Viral rebound occurred at 133 weeks after ETV was started. The 3TC(r) RT substitutions rtV173L, rtL180M, and rtM204V were present at study entry, and the additional substitutions rtI169T and rtM250V emerged during ETV-3TC combination treatment. Reduced ETV susceptibility in vitro required the rtM250V substitution in addition to the 3TC(r) substitutions. For liver transplant patient B (AI463015-B), previous famciclovir, ganciclovir, foscarnet, and 3TC therapies had failed, and RT changes rtS78S/T, rtV173L, rtL180M, rtT184S, and rtM204V were present at study entry. Viral rebound occurred after 76 weeks of therapy with ETV at 1.0 mg, with the emergence of rtT184G, rtI169T, and rtS202I substitutions within the preexisting 3TC(r) background. Reduced susceptibility in vitro was highest when both the rtT184G and the rtS202I changes were combined with the 3TC(r) substitutions. In summary, infrequent ETV resistance can emerge during prolonged therapy, with selection of additional RT substitutions within a 3TC(r) HBV background, leading to reduced ETV susceptibility and treatment failure.

Cryoprecipitate for the correction of coagulopathy associated with liver disease

In patients with liver disease at risk of pulmonary oedema, cryoprecipitate (small volume) might be a viable alternative to fresh frozen plasma (FFP, large volume) in the correction of coagulopathy. However, the efficacy of cryoprecipitate in these patients has not been tested. We evaluated the role of cryoprecipitate in the correction of the coagulopathy of liver disease. To establish initial evidence of efficacy, six consecutive patients with hepatic failure and coagulopathy received five units of cryoprecipitate. Then, using a crossover design, 11 consecutive patients were randomized to receive either four units of FFP or five units of cryoprecipitate. Pre and post infusion International Normalized Ratio (INR), activated Partial Thromboplastin Time (aPTT), fibrinogen D-dimers, Factors V and IX, and reptilase time were measured. In the first six patients, cryoprecipitate improved the INR, aPTT and fibrinogen concentration (P = 0.03). In the crossover study, FFP administration produced a greater improvement in INR (P = 0.007) and aPTT (P = 0.005) than cryoprecipitate. However, there were no differences in any of the other measured variables. One patient developed acute pulmonary oedema while receiving FFP. Cryoprecipitate improves the coagulopathy of liver disease. Four units of FFP are more efficacious than five units of cryoprecipitate. Cryoprecipitate may have a role in correction of the coagulopathy associated with liver disease where concerns about pulmonary oedema exist.

Paediatric liver transplantation [corrected] in Melbourne: the first 50 patients

To report the outcomes of the first 50 paediatric patients who have undergone liver transplantation (LT) at the Victorian Liver Transplant Unit, a retrospective review of case records was carried out. From December 1988 to December 2000, 108 patients 18 years or younger were referred for LT; 50 of these underwent a total of 53 transplants. The most common indications were biliary atresia (32%), metabolic disease (26%), and acute hepatic necrosis (26%). The majority of deaths (6/7) occurred in the 1st week after LT. The actuarial survival at 1 year was 88% (95% CI 75% to 94%) and at 10 years 85% (95% CI 71% to 93%). Survival rates were highest for children aged 3 to 14 years (95%) and lowest in those weighing less than 8 kg at the time of LT (66%). All 43 survivors are attending age-appropriate activities including kindergarten, school, and employment. The survival of patients undergoing LT in this unit compares favourably with those recorded by the Australia and New Zealand Transplant Registry and is commensurate with that reported by larger paediatric transplant programs overseas.

Hepatocellular carcinoma and chemoembolization

BACKGROUND

Chemoembolization is often used in the treatment of hepatocellular carcinoma; however, there are limited data on its efficacy in an Australian setting.

AIMS

To review retrospectively the experience of 21 patients with hepatocellular carcinoma who collectively had 36 chemoembolizations performed between October 1995 and February 1999 in a teaching hospital and liver transplant centre in Victoria.

METHODS

Selective catheterization of the right or left hepatic arteries was performed. A mixture of cisplatin 50 mg, epirubicin 50 mg, mitomycin C 10 mg, Lipiodol and gelfoam was injected. Computed tomography (CT) scans were performed at baseline and at 1-3 months after chemoembolization. Outcome measures included response rates, toxicity, progression-free and overall survival.

RESULTS

CT response rates: partial response 19% (n = 7), median duration 11 months (range 2+ to 37+); minor response 17% (n = 6), median duration 7 months (1+ to 12+); stable disease 42% (n = 15), median duration 3 months (1+ to 15 months); and progressive disease 22% (n = 8). Major toxicities included one case each of acute renal failure, contrast encephalopathy, gastric ulceration and hepatorenal failure. Median progression-free survival was 3 months (range 0-37+). Median overall survival was 15 months (range 6-50+).

CONCLUSION

Chemoembolization has a role in the palliative treatment of hepatocellular carcinoma. Our response rates and toxicity data are consistent with those in the published literature. However, new treatments are needed and prevention of disease by reduction in the prevalence of chronic hepatitis B and C will be required to significantly reduce mortality from this tumour.

Duck hepatitis B virus replication in primary bile duct epithelial cells

Primary cultures of intrahepatic bile duct epithelial (IBDE) cells isolated from duckling livers were successfully grown for studies of duck hepatitis B virus (DHBV). The primary IBDE cells were characterized by immunohistochemistry using CAM 5.2, a cytokeratin marker which was shown to react specifically to IBDE cells in duck liver tissue sections and in primary cultures of total duck liver cells. Immunofluorescence assay using anti-duck albumin, a marker for hepatocytes, revealed that these IBDE cultures did not appear to contain hepatocytes. A striking feature of these cultures was the duct-like structures present within each cell colony of multilayered IBDE cells. Normal duck serum in the growth medium was found to be essential for the development of these cells into duct-like structures. When the primary cultures of duck IBDE cells were acutely infected with DHBV, dual-labeled confocal microscopy using a combination of anti-DHBV core proteins and CAM 5.2 or a combination of anti-pre-S1 proteins and CAM 5.2 revealed that the IBDE cell colonies contained DHBV proteins. Immunoblot analysis of these cells showed that the DHBV pre-S1 and core proteins were similar to their counterparts in infected primary duck hepatocyte cultures. Southern blot analysis of infected IBDE preparations using a digoxigenin-labeled positive-sense DHBV riboprobe revealed the presence of hepadnavirus covalently closed circular (CCC) DNA, minus-sense single-stranded (SS) DNA, double-stranded linear DNA, and relaxed circular DNA. The presence of minus-sense SS DNA in the acutely infected IBDE cultures is indicative of DHBV reverse transcriptase activity, while the establishment of a pool of viral CCC DNA reveals the ability of these cells to maintain persistent infection. Taken collectively, the results from this study demonstrated that primary duck IBDE cells supported hepadnavirus replication as shown by the de novo synthesis of DHBV proteins and DNA replicative intermediates.

Effect of nucleoside analogue therapy on duck hepatitis B viral replication in hepatocytes and bile duct epithelial cells in vivo

BACKGROUND

Recent studies have implicated bile duct epithelial cells (BDEC) as a reservoir of hepatitis B virus (HBV) infection that may be particularly important in the development of post-liver transplant recurrence of hepatitis B. The aim of this study was to compare the effects of antiviral therapy on duck HBV (DHBV) expression in hepatocytes and BDEC and to determine if this was affected by biliary hyperplasia.

METHODS

Ducklings congenitally infected with DHBV received penciclovir (10 mg/kg per day) treatment from 9 days of age. In order to mimic the biliary hyperplasia that often accompanies severe post-liver transplant HBV recurrence, half the animals underwent bile duct ligation. Duck HBV-DNA in serum was measured at day 1, and serum and liver DHBV-DNA were determined when the animals were killed on day 17. Intrahepatic expression of viral preS1 antigen and DHBV-DNA was measured by immunohistochemistry and in situ hybridization, respectively.

RESULTS

Viraemia became undetectable in the penciclovir-treated animals at day 17, following 8 days of therapy. Examination of liver tissue revealed that all hepatocytes and the majority of BDEC contained DHBV preS1 antigen and DHBV-DNA. Penciclovir greatly reduced the intrahepatic viral burden, but there was no antiviral effect on viral markers within BDEC. Despite the increased number of BDEC after bile duct ligation, the same proportion of BDEC was seen to be infected, and this was unaffected by antiviral therapy.

CONCLUSIONS

In the duck model with and without biliary hyperplasia, penciclovir controls DHBV replication and reduces viral burden in hepatocytes, but not in BDEC. The BDEC appear to be an important reservoir of virus that is relatively unaffected by antiviral treatment, and may play an important role in disease persistence and relapse following cessation of therapy.

Relationships among liver and kidney volumes, lean body mass and drug clearance

AIMS

To determine whether lean body mass (LBM), a possible surrogate of liver and kidney volumes, correlates with hepatic and renal drug clearances.

METHODS

Twenty-one disease-free patients with a history of cancer and with normal hepatic and renal function were studied. Salivary pharmacokinetics of oral antipyrine (1200 mg) and 24 h creatinine clearance were determined following the determination of LBM by dual energy X-ray absorptiometry and the determination of liver and kidney volumes by helical CT scanning.

RESULTS

Liver volume correlated with LBM (r2=0.21, P=0.04), body surface area (BSA) (r2=0.54, P<0.001), and total body weight (TBW) (r2=0.61, P<0.001). Kidney volume correlated with LBM (r2=0.49, P<0.001), BSA (r2=0.43, P=0.002) and TBW (r2=0.24, P=0.03). Stepwise multiple regression analysis, incorporating the independent variables of age, height, weight, sex, BSA, LBM, alcohol consumption, smoking status and liver volume and the dependent variable antipyrine clearance, indicated that LBM was the only independent correlate of antipyrine clearance. A stepwise multiple regression analysis with kidney volume in the independent variables, and creatinine clearance as dependent variable, showed that kidney volume and age were the only independent correlates of creatinine clearance. A nomogram using serum creatinine and LBM was comparable with the Cockcroft and Gault nomogram in calculating creatinine clearance.

CONCLUSIONS

Of the anthropometric variables tested, LBM was the only determinant of antipyrine clearance, but this was not due to a relationship between LBM and liver volume. By contrast, the relationship between creatinine clearance and LBM appeared to be due to a relationship between LBM and kidney volume.

Hepatitis G virus and fulminant hepatic failure: evidence for transfusion-related infection

BACKGROUND/AIMS

In the majority of cases of fulminant "viral" hepatitis in Australia, no known aetiological agent can be isolated. We have examined the possible role of the recently discovered hepatitis G virus (HGV) in such cases.

METHODS

An HGV specific reverse transcription polymerase chain reaction (RT-PCR) was performed on pre- and post-liver transplant serum from 14 patients who were referred for transplantation at our unit between 1989 and 1995 for unexplained fulminant hepatic failure. Eleven patients successfully underwent transplantation and three died while waiting for a suitable donor organ. Hepatitis viruses A-E were excluded by standard serological and PCR based testing. HGV RT-PCR was also performed on 21 other, randomly selected, liver transplant recipients ("controls").

RESULTS

The 14 fulminant cases were HGV RT-PCR negative prior to transplantation while five of 21 controls were positive. Post-transplant, eight of the 11 fulminant patients were found to be HGV RT-PCR positive and the same five controls remained HGV RT-PCR positive. In three of the eight fulminant patients the HGV infection resolved.

CONCLUSIONS

Our data indicate that HGV infection is unlikely to be responsible for fulminant hepatitis and that it is probably acquired from blood and/or blood products during the transplantation process. Furthermore, long-term carriage of HGV post-transplant is not associated with clinically apparent liver disease.

Hepatitis B virus polymerase mutations during antiviral therapy in a patient following liver transplantation

BACKGROUND/AIMS

The purpose of this study was to investigate possible resistance mutations which arose in the polymerase gene of hepatitis B virus (HBV) in a patient with severe recurrent HBV infection following liver transplantation. The patient's management included antiviral chemotherapy for almost 4 years comprising ganciclovir, foscarnet and famciclovir. In the last 2.5 years of famciclovir treatment, an increase in serum HBV DNA levels and a reduced sensitivity of the virion-associated DNA polymerase to penciclovir triphosphate were observed.

METHODS

The viral polymerase gene and X gene were sequenced from serum samples collected at representative time intervals covering the entire treatment period.

RESULTS

No mutations were detected in the X gene. Three nucleotide mutations, each of which resulted in an altered amino acid sequence, were detected in the polymerase gene after 816 days of total antiviral therapy (370 days of famciclovir). Two of these mutations were detected by direct sequencing and the third was detected after cloning and was present in 10% of the clones. All three mutations occurred in "region B" of RNA-dependent DNA polymerases. The HBV polymerase has similarities to both RNA and DNA polymerases. These mutations in the HBV polymerase gene were located in a similar area to the penciclovir-induced mutations observed in the herpes simplex virus DNA polymerase gene.

CONCLUSIONS

Three mutations within the HBV polymerase gene were detected which were associated with a reduced penciclovir sensitivity.

Budd-Chiari syndrome: intractable ascites managed by a trans-hepatic portacaval shunt

Transjugular intrahepatic portosystemic shunts (TIPS) have recently been used to manage the portal hypertensive complications of the Budd-Chiari syndrome. We report this application of TIPS (to our knowledge the first such application in Australia) in a young man with an excellent result and no major complications. This treatment offers an alternative to portacaval shunt surgery and has the advantage of bypassing a stenosed or compressed inferior vena cava. Additionally, the procedure does not complicate liver transplantation surgery if this is indicated at a later date.

Retransplantation for precore mutant-related chronic hepatitis B infection: prolonged survival in a patient receiving sequential ganciclovir/famciclovir therapy

Retransplantation for hepatitis B-related liver allograft failure is rarely successful. Recurrence of infection is almost universal, and the second allograft is invariably lost more rapidly than the first. In a recent multicenter study, only 1 of 20 hepatitis B virus (HBV)-positive patients who underwent liver retransplantation survived beyond 6 months. This report describes the long-term effect of antiviral therapy in a 56-year-old man who was retransplanted for HBV-related allograft loss 14 months after his initial liver transplant. He was treated after the second transplant with intravenous daily ganciclovir. After 10 months of this therapy HBV recurrence was detected. After a change to oral famciclovir therapy, there was a decrease in serum HBV DNA and amino-transferase levels and an improvement in the patient's clinical condition. Famiciclovir therapy has now been continued for 26 months, and the patient remains well 3 years after his second transplant, despite persistent HBV infection and progression to cirrhosis. These observations indicate that the use of long-term antiviral therapy offers promise for improving outcomes in patients who undergo retransplantation after HBV-related liver allograft failure.

Lymphoproliferative disease of donor origin arising in patients after orthotopic liver transplantation

BACKGROUND

Lymphoproliferative disease is a well recognized complication of organ transplantation and in many cases is associated with Epstein-Barr virus (EBV) infection. It is widely though that posttransplantation lymphoproliferative disease (PTLPD) arises from recipient lymphoid cells. However, solid organ allografts are likely to include donor lymphoid tissue around or within the transplanted organ. Therefore, it is possible that transplanted donor lymphocytes may proliferate to form PTLPD:

METHODS

The genetic origin of tumor cells was determined by microsatellite DNA fingerprinting using the polymerase chain reaction (PCR). Their EBV association and clonality were established by PCR amplification of DNA extracted from formalin fixed, paraffin embedded tissue using primers to conserved regions of the EBV genome and the immunoglobulin heavy chain gene, respectively.

RESULTS

The authors have demonstrated two cases of lymphoproliferative disease that were derived from donor lymphocytes in orthotopic liver transplant recipients. In both cases, the proliferating cells were EBV DNA positive. Furthermore, the PTLPD was restricted to allograft tissue around the porta hepatis. However, the two cases differed in their clonal properties and response to treatment: one case was oligoclonal and regressed after antiviral therapy and a modest reduction of immunosuppression, whereas the other contained two clonal populations and was controlled only after treatment with antineoplastic chemotherapy.

CONCLUSION

This study has demonstrated two cases of PTLPD that were derived from donor lymphoid tissue. Although both cases were associated with EBV and remained localized to allograft tissue, their clonality and response to therapy differed.

Combination antiviral therapy controls severe post-liver transplant recurrence of hepatitis B virus infection

The authors have successfully used combination ganciclovir and foscarnet chemotherapy to control viral replication following liver transplantation in a patient with severe recurrence of hepatitis B virus (HBV) infection. The disease was characterized by extremely high viraemias, deteriorating liver function, and high levels of intra-hepatic hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg). Treatment resulted in a greater than 30-fold reduction in serum HBV DNA and HBsAg levels. Liver function tests returned to normal and the histological progression of the disease was arrested. Hepatic cytoplasmic HBsAg decreased substantially but there was little change in HBcAg, implicating HBsAg rather than HBcAg in the liver injury. Combination antiviral chemotherapy using agents such as ganciclovir and foscarnet may offer a new approach to the management of post-transplant recurrence of HBV.

Oral fluticasone propionate in active distal ulcerative colitis

Fluticasone propionate is a new corticosteroid with low systemic bioavailability. This study reports the outcome of a double blind clinical trial comparing oral fluticasone propionate (5 mg four times daily) with placebo for the treatment of active distal ulcerative colitis. Sixty patients were treated for four weeks, with assessments at two and four weeks. One patient was withdrawn when she was found to have amoebiasis. Thus, results are presented for 29 patients who received placebo and 30 who received fluticasone propionate. The two groups were well matched for age, sex, length of history, and extent of disease. After four weeks of therapy the clinical, sigmoidoscopic, and histological responses were similar in the two groups. It is concluded that fluticasone propionate (5 mg four times daily) is not effective treatment for active distal ulcerative colitis.

Hepatitis due to nitrofurantoin

OBJECTIVE

To report three cases of hepatitis related to the use of nitrofurantoin.

CLINICAL FEATURES

Two patients who had been taking nitrofurantoin for several years, presented with severe liver failure. In both, the drug had been continued despite evidence of liver injury. A third patient presented with acute hepatitis after six weeks of nitrofurantoin therapy.

INTERVENTION AND OUTCOME

One of the patients with liver failure died and the other underwent a successful liver transplantation. The third patient recovered after withdrawal of the drug.

CONCLUSION

These cases emphasise the potential for serious hepatic reactions with nitrofurantoin, the danger of continuing the drug once liver damage has occurred and the need for careful monitoring of liver function during long-term therapy.