Liver transplantation for chronic viral hepatitis

Functional Hepatocyte-Like Cells Derived from Human Bone Marrow Mesenchymal Stem Cells on a Novel 3-Dimensional Biocompatible Nanofibrous Scaffold

Aim

To supporting growth and functional differentiation of adult stem cells into hepatocytes in a well-controlled manner, we performed differentiation of human bone marrow mesenchymal stem cells (hBMSCs) to hepatocytes-like cells on a constructed 3-dimensional (3D) nanofibrous biocompatible scaffold.

Methods

After characterization of the hBMSCs isolated from human bone marrow, the performance of the cells seeded and their proliferation on the scaffold was evaluated by scanning electron microscopy (SEM) and 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Different approaches such as immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR), and biochemical assays were used to estimate the ability of hBMSC-derived cells to express hepatocyte-specific markers.

Results

Scanning electron micrographs and MTT analysis revealed the cells were able to expand and remained biologically and metabolically active for 21 days. Immunocytochemical analysis of albumin and α-fetoprotein showing the accumulation of these markers in differentiated cells was confirmed by RT-PCR. Additional markers such as cytochrome P450 3A4, cytokeratin-18, and cytokeratin-19 detected by RT-PCR showed progressive expression during 3 weeks of differentiation on 3D scaffold. The hepatocyte-like cells displayed several characteristics of metabolic functions as judged by production of albumin, urea, transferrin, serum glutamic pyruvic transaminase (SGPT), and serum oxaloacetate aminotransferase (SGOT). Levels of above-mentioned markers, except SGOT in differentiated cells on scaffold, were found to be significantly greater than in the 2D culture system (p<0.05).

Conclusion

Overall data suggest that the engineered nanofibrous scaffold is a conductive matrix for functional hBMSC-derived hepatocyte-like cells and is promising for maintenance of hepatocytes suitable for implantation.

De Novo Hepatitis B Infection From Hepatitis B Core Antibody-Positive Donors During Hepatitis B Immunoglobulin Prophylaxis

De novo hepatitis B infection in patients receiving liver transplants from hepatitis B core antibody-positive donors is well known, but the effective prevention strategy has not been well established. In our hospital, recipients receive hepatitis B immunoglobulin monotherapy if they are hepatitis B surface antigen negative at the time of transplant and are receiving a liver from a hepatitis B core antibody-positive donor. Since August 2006, we have had 4 patients who were naïve to hepatitis B virus and received a hepatitis B core antibody-positive graft. Two patients died of other causes, and 2 patients, who had liver transplant in October 2006 and October 2009, developed de novo hepatitis B. Both patients were tested annually for serum hepatitis B surface antigen as part of routine visit. Tests were negative; however, both patients recently became hepatitis B surface antigen positive. Other laboratory results, including liver function test, were unremarkable, except HBsAb titer was undetectable even though hepatitis B immunoglobulin monotherapy had been administrated 2 months previously in both patients. The patients had hepatitis B virus DNA levels of 3.07E+08 copies/mL and 1.51E+08 copies/mL. We suggest that additional prophylactic therapies above hepatitis B immunoglobulin monotherapy are needed for these recipients.

Liver transplantation from anti-hepatitis C virus-positive donors: our experience

BACKGROUND

Hepatitis C (HCV) is among the most common causes of end-stage liver disease worldwide. The donor shortage leads us to consider alternative organ sources such as HCV-positive donors. The outcomes of these transplants must be evaluated thoroughly since there is universal recurrence of disease among HCV-positive liver transplant recipients.

METHODS

From January 2005 to April 2011, we performed 143 liver transplants (OLT) to treat end-stage liver disease secondary to HCV infection. Thirteen patients (9,1%) received livers from HCV-positive donors. A control group consisted of 130 HCV-positive patients who underwent OLT during the same period with organs from HCV-negative donors. Donor HCV status was assessed by 2 tests: HCV antibodies and viral load. Not only recipient and graft survivals were analyzed, but also frequency, timing and severity of hepatitis recurrence.

RESULTS

Among 143 transplants performed in HCV-positive recipients during a 6-year period from January 1, 2005, to April 30, 2011, 9.1% of patients received an organ from an anti-HCV-positive donor, 72.7% of whom showed a negative viral load. The vast majority (80%) of our patients suffered hepatitis during their follow-up, 22.4% of which were severe cases.

CONCLUSIONS

No significant difference in patient or graft survival was observed between the 2 groups. A high percentage of grafts with initial positive serology for HCV showed no viral replication. Grafts from HCV-positive donors can be considered to be a safe, effective source for liver donation.

Treatment of acute hepatic failure in mice by transplantation of mixed microencapsulation of rat hepatocytes and transgenic human fetal liver stromal cells

Microencapsulation-mediated cell therapy overcomes the immune incompatibility between donor and recipient in transplantation. The aim of this study was to investigate the effects of transplantation of microcapsules containing a mixture of rat hepatocytes and human fetal liver stromal cells (hFLSCs), engineered to produce basic fibroblast growth factor (bFGF), on acute liver failure (ALF) in mice. In vitro experiments showed that different combinations of microencapsulated rat's hepatocytes and stromal cells survive, grow, and function better in three-dimensional conditions. The metabolic activity of rat hepatocytes co-microencapsulated with hFLSCs, particularly when engineered to produce bFGF (FLSCs/bFGF), is significantly higher than that of microcapsules with rat hepatocytes alone. Intraperitoneal transplantation of the encapsulated hepatocytes with FLSCs/bFGF increased the survival rate and improved liver function of an ALF mouse model induced by a 70% partial hepatectomy in BALB/C mice. Moreover, dramatic liver regeneration was observed 2 days after transplantation in the group that received intraperitoneal transplantations of encapsulated hepatocytes with FLSCs/bFGF. Therefore, transplantation of encapsulated hepatocytes and hFLSCs/bFGF may be a promising strategy to treat ALF or related liver diseases.

Liver tissue engineering: promises and prospects of new technology

Today, many patients suffer from acute liver failure and hepatoma. This is an area of high unmet clinical need as these conditions are associated with very high mortality. There is an urgent need to develop techniques that will enable liver tissue engineering or generate a bioartificial liver, which will maintain or improve liver function or offer the possibility of liver replacement. Liver tissue engineering is an innovative way of constructing an implantable liver and has the potential to alleviate the shortage of organ donors for orthotopic liver transplantation. In this review we describe, from an engineering perspective, progress in the field of liver tissue engineering, including three main aspects involving cell sources, scaffolds and vascularization.

Factors released from cholestatic rat livers possibly involved in inducing bone marrow hepatic stem cell priming

Previous studies have shown that bone marrow beta 2m(-)/Thy-1+ hepatic stem cells (BMHSCs) were able to engraft in vivo and differentiate into functioning hepatocytes in vitro. Our transcriptomic profiling on BMHSCs derived from rats subjected to common bile duct ligation (CBDL) demonstrated CBDL-derived beta 2m(-)/Thy-1+ BMHSCs expressed hepatocyte-like genes and shared more commonly expressed genes with hepatocytes, suggesting that an "on-site" priming of BMHSCs into hepatocyte lineage was initiated under the condition of CBDL. In this paper, transcriptomic profiling was carried out on livers from rats with CBDL to identify candidate factors released from cholestatic livers possibly involved in the priming of BMHSCs using Affymetrix Rat Genome U34A arrays. In CBDL rat livers, 1,091 probe sets were differentially expressed, of which 188 up-regulated probe sets were annotated as "extracellular" components. Gene ontology analysis showed many up-regulated genes belonged to cytokines, chemokines and growth factors, including Il1b, Il18, Ptn, Spp1, Grn, Ccl2, Cxcl1, Pf4, Tgfb, and Tgfb3. Cell differentiation and proliferation regulation factors such as Dmbt1, Efna1, Lgals1, Lep, Pmp2, and Gas6 were also induced in CBDL livers. Furthermore, many proteolysis and peptidolysis genes such as Mmp2, Mmp12, Mmp14, and Mmp23 were up-regulated in CBDL livers. Gene expression profiling showed that many cytokine-, chemokine-, growth factor- as well as certain extracellular protein-related genes were induced in CBDL livers, suggesting that these genes may be involved in hepatic BMHSCs priming.

Liver transplantation outcomes in patients with cirrhosis and hepatocellular carcinoma: experience of a single center in a viral hepatitis endemic area

Our center has performed 205 orthotopic liver transplantations (OLT) in 201 patients. Hepatocellular carcinoma (HCC) was discovered in 32 (15%) patients, 5 of whom were diagnosed incidentally in recipient explants. The main underlying diagnosis was viral hepatitis (n = 28; 87.5%). Most patients (17; 53.1%) were diagnosed as having Child class B cirrhosis. Single tumors measuring <3 cm were diagnosed in 29 (90.6%) patients. Downstaging chemoembolization was performed in 7 (21.8%) patients. Preoperative aFP levels were normal in 20 (62.5%) patients. In the rest (n = 12; 37.5%), aFP levels normalized immediately after the OLT. In the latter group, 2 patients had a delayed (2 years) postoperative increase in aFP levels; both patients had tumor recurrence in the graft. All patients with hepatitis B received antiviral treatment with HBIG and lamivudine. There were 9 deaths (28.1%) in the immediate postoperative period (<30 days). One-year survival rate was 62.5% (n = 20). Actuarial 5-year survival rate was 55%, and actuarial 10-year survival rate was 40%. In conclusion, OLT has become the standard treatment for patients diagnosed with HCC in a population that shows cirrhosis most of the time to be secondary to viral hepatitis, provided that recipients are selected according to the size of the neoplasm and that they receive adequate antiviral prophylaxis.

Immunization issues before and after solid organ transplantation in children

Solid-organ transplant recipients are at risk from various infectious diseases, many of which can be prevented by immunizations that could reduce morbidity and mortality. However, it is not uncommon for children requiring transplantation to have received inadequate or no immunizations pre-transplant. Every effort should be made to immunize transplant candidates early in the course of their disease according to recommended schedules prior to transplantation. It is also important to immunize their household contacts and healthcare workers. In this review, we summarize the major immunization issues for children undergoing transplantation, the data currently available on immunization safety and efficacy, and suggest immunization practices to reduce vaccine-preventable disease. There is a real need for a standardized approach to the administration and evaluation of immunizations in this group of patients.

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Efficacy of Engineered Liver Tissue Based on Poly-L-lactic Acid Scaffolds and Fetal Mouse Liver Cells Cultured with Oncostatin M, Nicotinamide, and Dimethyl Sulfoxide

To assess the feasibility of liver tissue equivalents based on selective propagation and differentiation of hepatocyte progenitors in three-dimensional (3D) culture, the efficacy of fetal mouse liver cells cultured in poly-L-lactic acid (PLLA) scaffolds in the presence of nicotinamide, dimethyl sulfoxide, and oncostatin M was investigated both in vitro and in vivo. The albumin production of PLLA-cultured fetal mouse liver cells in the presence of these three factors was remarkably enhanced with culture time, and after 4 weeks it attained almost the same production found in adult mouse hepatocytes cultured for 3 days in PLLA scaffolds, based on the unit DNA amount. In addition, implantation of engineered liver tissue based on this in vitro PLLA culture system into the peritoneal cavity of 70% hepatectomized mice showed a remarkably higher presence of albumin-positive engrafted cells 15 days after the operation when compared with fetal mouse liver cells or adult mouse hepatocytes freshly isolated and cultured for 1 day. These results demonstrate that the basic concept regarding the engineering of liver tissue equivalents based on in vitro selective propagation and differentiation of hepatocyte progenitors in 3D biodegradable scaffolds shows promise for future liver tissue engineering.

Immunization of children after solid organ transplantation

The array of immunizations commonly used in childhood has risen in an attempt to prevent many of the potentially serious infections of infancy and childhood. In this article, the authors provide rational guidelines for vaccination of these children. The authors briefly review the susceptibilities caused by immunosuppression in these patients, discuss the problems with various immunizations, and make individual recommendations regarding the use of each vaccine. Most recommendations are based on inferences from populations that may not be directly comparable to the transplantation population (patients with HIV or cancer or patients who have undergone bone marrow transplant), from case reports, and from small series of patients. The best recommendations ultimately must await the results of controlled trials of immunization.

Use of Ultrathin Shell Microcapsules of Hepatocytes in Bioartificial Liver-Assist Device

We previously encapsulated hepatocytes in ultrathin shell microcapsules and showed them to have enhanced differentiated functions over cells cultured in monolayer. Here we have used these microencapsulated hepatocytes in a bioartificial liver-assisted device (BLAD) with a rat hepatectomy model. Primary rat hepatocytes were encapsulated in 150- to 200-microm microcapsules, using an electrostatic droplet generator. The microencapsulated hepatocytes exhibited good in vitro urea synthesis activity in plasma from rats with fulminant hepatic failure (FHF). The ex vivo hemoperfusion was conducted in FHF rats by perfusing plasma at a rate of 1-2 mL/min through 1.5-2 x 10(8) encapsulated hepatocytes packed into a packed-bed bioreactor. Hemoperfusion with the bioreactor was initiated 5 h after operative induction of liver failure and continued for 7 h. The BLAD-treated rats showed improvements over the control groups in survival time and metabolic indicators, including ammonia and total bilirubin levels. Furthermore, expanded bed adsorption (EBA) detoxification technology using Streamline-SP resin was explored to complement the bioreactor with microencapsulated hepatocytes. In vitro experiments indicated that serum ammonia could be specifically removed in dose-dependent manner, whereas the total serum proteins were unaffected by the resin. In ex vivo experiments, hemoperfusion with the resin was initiated 3 h after operative induction of liver failure and continued for 7 h. The resin-treated rats showed obvious serum ammonia removal with no observable total blood protein and blood cell adsorption. Therefore, Streamline-SP resin can potentially be integrated into a BLAD for improved efficacy.

Cost-effective and safe ambulatory long-term immunoprophylaxis with intramuscular instead of intravenous hepatitis B immunoglobulin to prevent reinfection after orthotopic liver transplantation

BACKGROUND

Hepatitis B (HBV)-infected patients receive an anti-HBs immunoprophylaxis [hepatitis B immunoglobulin (HBIG) titre of more than 100 IU/L] in combination with lamivudine to prevent reinfection after orthotopic liver transplantation (OLT). In comparison with intramuscular (i.m.) HBIG, costs for intravenous (i.v.) HBIG are found to be extremely high. We therefore studied patients' outcome (i) after a switch from i.v. to i.m. HBIG and (ii) the outcome after the patients were initially treated with i.m. HBIG after discharge from the hospital.

METHODS

(i) Six outpatients were switched from 2000 IU i.v. HBIG (Hepatect) administered every 2 wk to 2000 IU i.m. HBIG (Hepatitis-B-Immunoglobulin Behring) given once a month. (ii) Six other outpatients were directly treated with i.m. HBIG every 4 wk after OLT. All patients also received 100 mg lamivudine/d.

RESULTS

Patients switched from i.v. to i.m. HBIG had stable anti-HBs titres (i.v. HBIG: 180 +/- 37 IU/L vs. i.m. HBIG: 173 +/- 23 IU/L). Patients directly treated with i.m. HBIG also had sufficient anti-HBs titres (176 +/- 31 IU/L). Intramuscular application of HBIG was well tolerated by all patients and no side-effects were observed in patients receiving i.m. HBIG. In comparison with the protocol using i.v. HBIG, the costs of i.m. treatment were 60% lower.

CONCLUSION

Long-term administration of i.m. HBIG saves up to 60% of the usual costs for i.v. prophylaxis of HBV reinfection in patients after OLT. In combination with lamivudine, long-term i.m. HBIG therapy is as efficient as i.v. HBIG treatment, but its lower costs clearly favour its use in preventing HBV reinfection after OLT.

The outcome of liver grafts procured from hepatitis C-positive donors

BACKGROUND

The growing prevalence of hepatitis C virus (HCV) infection in the general population has resulted in an increased frequency of potential organ donors that carry the virus. The survival of grafts from HCV+ donors has not been studied in detail.

METHODS

Two study populations were examined retrospectively to assess the survival of liver grafts procured from HCV+ donors. First, we evaluated the survival of all 13 HCV+ and 103 HCV- grafts that were transplanted at our institution to HCV+ recipients from January 1, 1995 to December 31, 1999. In parallel, we analyzed a subset of the United Network for Organ Sharing (UNOS) liver transplant database from the same 5-year time period that was comprised of 14,195 adult patients for whom donor and recipient HCV serologies were known. Kaplan-Meier graft survival for both patient populations was calculated based on donor and recipient HCV serologic status. A Cox proportional hazards analysis was performed on UNOS data to identify variables independently predicting graft survival.

RESULTS

For transplants performed at our institution, we found no statistically significant difference in the Kaplan-Meier graft survival of HCV+ and HCV- grafts transplanted to HCV+ recipients (P=0.68). The incidence of biopsy-proven, recurrent HCV posttransplant was similar in recipients receiving either HCV+ or HCV- grafts (4/13 vs. 18/103, chi-square P=0.211). Analysis of UNOS data revealed that the survival of HCV+ grafts in HCV+ recipients was equivalent to the survival of HCV- grafts in HCV+ recipients. Unexpectedly, the survival of grafts in HCV+ recipients in general was significantly inferior to that of grafts in HCV- recipients. Multivariate analysis of all patients found recipient but not donor HCV status to be independently predictive of graft survival.

CONCLUSIONS

Analysis of data from a single center and the national UNOS database suggests that transplantation of liver allografts from HCV+ donors to HCV+ recipients results in graft survival comparable to HCV- grafts transplanted to HCV+ recipients. In contrast, recipient HCV positivity is an independent predictor of graft failure compared with patients transplanted for other causes of liver disease.

Hepatic progenitors and strategies for liver cell therapies

Liver cell therapies, including liver cell transplantation and bioartificial livers, are being developed as alternatives to whole liver transplantation for some patients with severe liver dysfunction. Hepatic progenitors are proposed as ideal cells for use in these liver cell therapies given their ability to expand extensively, differentiate into all mature liver cells, have minimal immunogenicity, be cryopreservable, and reconstitute liver tissue when transplanted. We summarize our ongoing efforts to develop clinical programs of hepatic progenitor cell therapies with a focus on hepatic stem cell biology and strategies that have emerged in analyzing that biology.

Hepatitis C virus and liver transplantation

Advances in immunosuppressive therapy, operative techniques, and perioperative management have resulted in long-term patient survival rates approaching 90% following liver transplantation for chronic viral hepatitis. The increasing number of referrals for liver transplantation reflects the impact of chronic HCV infection as a cause of end-stage liver disease. Unlike hepatitis B, there is still no effective treatment in preventing recurrent hepatitis C after liver transplantation. The spectrum of allograft injury related to universal HCV infection recurrence ranges from no evidence of histologic injury to mild inflammation to severe disease with allograft failure in small proportion of patients. Various factors may explain these differing outcomes, including degree of pretransplantation viremia, HLA compatibility, presence of more pathogenic HCV genotypes, integrity of cellular immune response, and type of immunosuppression. Fortunately, patient survival does not seem to be affected short-term; the long-term outcome of liver transplantation for chronic hepatitis C is unclear but is likely to be decreased. Combination therapy with interferon plus ribavirin seems to be a promising treatment strategy for posttransplantation recurrent hepatitis C, and the use of pegylated interferon plus ribavirin may improve these results. Patients with moderate to severe allograft hepatitis are appropriate candidates for combination antiviral therapy. Histopathologically documented recurrent hepatitis C in liver transplant recipients is associated with impaired quality of life, inferior physical condition, and a higher incidence of depression compared with patients who did not have HCV and in those without HCV recurrence. In conclusion, it is possible that the continued improvements in antiviral therapy against HCV infection may ultimately decrease the number of patients needing liver transplantation. Suitable candidates with chronic HCV infection thus warrant treatment with pegylated interferon plus ribavirin combination therapy in the hope of decreasing disease progression. Recent studies, which require confirmation, suggest that nonresponders to standard antiviral therapy may benefit from maintenance therapy. The donor pool for patients with chronic hepatitis C and decompensated cirrhosis can be improved by using HCV-positive donors and by increasing utilization of newer surgical techniques, including adult-to-adult living-donor liver transplantation and split-liver transplantation.

High-throughput quantitative analysis of hepatitis B virus DNA in serum using the TaqMan fluorogenic detection system

Reproducible quantitative assays to detect viral nucleic acids have proven useful in defining disease progression and following response to therapy in a wide variety of viral infections. We describe the development of a quantitative assay to detect hepatitis B virus (HBV) DNA using real-time fluorescent-probe polymerase chain reaction (PCR) (TaqMan). The assay is highly reproducible, highly automated, and much more sensitive than the currently used branched-chain DNA (bDNA) assay for HBV. The quantitative PCR assay accurately detected samples ranging from 10 to 10(9) copies of HBV DNA per milliliter. Of 157 serum samples submitted for HBV quantitation, 119 were positive by TaqMan PCR versus only 55 by bDNA (P <.001). All 55 bDNA-positives were positive by TaqMan. Of the 77 samples with detectable HBV-DNA titers below 3.75 x 10(5) copies by TaqMan, only 13 were detected by bDNA. We tested 119 patients negative for all HBV serologic markers, and all tested negative in the TaqMan assay. HBV DNA was detected by TaqMan in 164 of 195 (84%) of hepatitis B surface antigen (HBsAg)-positive samples. Among hepatitis B e antigen (HBeAg)-positive samples, median titers were 4. 3 x 10(6) copies/mL versus 322 copies/mL in HBeAg-negative samples (P =.012). The TaqMan assay for HBV DNA is highly sensitive and reproducible and thus appears useful in accurately defining levels of viral replication among persons with HBV infection.

Antibodies for the prevention and treatment of viral diseases

This paper reviews current use and evolving role of polyclonal and monoclonal antibody products for the prevention and treatment of viral diseases. Antibodies continue to be indicated for prophylaxis either prior to an anticipated exposure especially in situations of travel, or more commonly following an exposure. The predominant indication for use of antibody products is to prevent infection. With the availability of vaccines for the prevention of chickenpox, hepatitis A, hepatitis B, measles, rabies and smallpox, the role of passive immunization is reserved for susceptible individuals and those at high risk for complications of infection. Risks of transmission of infections associated with use of human plasma-derived products have been reduced by improvements in donor screening and virus removal and inactivation procedures. An additional safety concern has been addressed by the removal of thimerosal as a preservative. Within the last 5 years, two antibodies have been licensed for a viral indication, RespiGam and Synagis both for prevention of respiratory syncytial virus infection. RespiGam is a human plasma derived antibody and Synagis is a humanized monoclonal antibody, the first such antibody to be licensed for an infectious disease indication. CytoGam for prevention of cytomegalovirus infection in kidney transplant patients has recently been granted an expanded indication to include use in lung, liver, pancreas and heart transplant patients. As the use of therapeutics becomes more sophisticated, researchers may find better ways of using antibody products.

Immunization of pediatric solid organ transplant candidates and recipients

Organ transplantation has evolved from an experimental procedure to an accepted treatment for otherwise irreversible or congenital disorders. The immunosuppression necessary to prevent rejection enhances the severity of many infectious diseases and may potentially attenuate the response to vaccines designed to prevent disease. In spite of the frequency and severity of infectious diseases in organ transplant recipients, many children are not fully vaccinated before transplantation. The safety and efficacy of many of the currently available vaccines for solid organ transplant recipients have not been evaluated. We review the currently available data on immunization safety and efficacy, discuss experimental vaccines, and outline strategies to avoid vaccine-preventable diseases in pediatric organ transplant recipients.

Indications for liver transplantation in patients with chronic hepatitis B and C virus infection and hepatocellular carcinoma

Patients with chronic hepatitis B virus (HBV) infection were not accepted for liver transplantation in Asia in the past because the hepatitis B immune globulin (HBIG) used to prevent post-transplantation recurrence was very expensive and it was generally believed that Asians with hepatitis B fared worse than Caucasians after liver transplantation. The availability of lamivudine has altered the indication of liver transplantation for these patients. Twenty-five Chinese patients with chronic HBV infection were given lamivudine as primary prophylaxis against HBV re-infection before transplantation. Five patients died within 40 days of transplantation. After a median follow-up period of 14 months (range, 5-39), 17 patients had lost serum HBsAg from 4 days to 27 months post transplantation, but it reappeared in three patients 4-12 months later. Antibody to HBsAg was detected periodically in the serum of 1 patients who had lost HBsAg. At the last follow-up, six patients were HBsAg-positive and HBV DNA was detected in only one of them. The indication for liver transplantation for chronic hepatitis C virus (HCV) infection is not as strict as for patients with chronic HBV infection because the long-term survival is similar to that of non-hepatitis C patients, even though re-infection by HCV in the recipients is nearly universal. The main issue in the selection of patients with HCV for liver transplantation is therefore identification of criteria that can predict re-infection and development of cirrhosis. These include factors such as multiple episodes of rejection, use of OKT3, pre-transplant viral load and genotype, but reports are not consistent and so there are no well-defined selection criteria. The selection criteria for patients with hepatocellular carcinoma are now well defined. Many studies have confirmed that a tumour > 5 cm, and showing vascular invasion, and poor differentiation adversely affects survival. In practice, only patients with a tumour < 5 cm and Child's C cirrhosis are accepted for liver transplantation. Transarterial oily chemoembolization and intralesional alcohol injection are used to control or down-stage the tumour while patients wait for a cadaveric liver graft.

Hepatitis B

The management of acute HBV infection is supportive. Specific treatment is not indicated for HBV carriers because they often have no evidence of liver injury, and, further, do not respond to currently available therapies. Interferon monotherapy is best indicated for patients with chronic replicating HBV infection and evidence of chronic hepatitis. There is an increased likelihood of clearing HBsAg with interferon monotherapy as compared to lamivudine. Lamivudine is an oral nucleoside analog that is better tolerated than interferon. The clinical situations for its use are far more than interferon monotherapy. Lamivudine should be used in patients with decompensated cirrhosis and also in transplantation, both before and after transplantation. The post-transplant use of hepatitis B immune globulin (HBIG) and lamivudine combination therapy may be better for recipients who are identified in a replicative phase prior to transplantation. Hepatitis B coinfection with one or more viruses, HCV, HDV, or HIV, may occur. Both interferon and lamivudine have been useful in these patients. However, the data are sparse and heterogeneous. Therapy with one or both drugs will have to be tailored to the clinical situation. Combination therapy with immunomodulatory and/or antiviral drugs are what we will be looking toward in the future.