Serological evidence of past hepatitis B infection in liver donor and hepatitis B infection in liver allograft

Risk of disease transmission in an expanded donor population: the potential of hepatitis B virus donors

PURPOSE OF REVIEW

Lack of availability of donor organs is a constant challenge that patients and providers face in transplantation. To address this shortage, donors that test positive for hepatitis B, in particular those with resolved infection, have been increasingly utilized in clinical practice. We review here the potential risks for the recipient and the advances in hepatitis B management that have made use of these donors a well tolerated and advisable proposition.

RECENT FINDINGS

As routine administration of antiviral prophylaxis in the posttransplant setting among those deemed high risk for transmission, outcomes for recipients of hepatitis B donors, including liver transplant recipients, have been comparable to uninfected donors. Universal hepatitis B nucleic acid testing of donors has also enhanced our ability to accurately inform recipients regarding transmission risk. Appropriate use of prophylaxis and careful monitoring for transmission posttransplant is key to ensuring no adverse outcomes occur.

SUMMARY

Treatment of hepatitis B has evolved over the past two decades. Expanding the donor pool with hepatitis B donors is now well tolerated, ethical, and advantageous to the transplant community at large. A clear discussion with recipients on the substantial benefit and low harm of using hepatitis B donors will lead to greater acceptance and utilization of these organs.

Incidence and characteristics of HBV reactivation in hematological malignant patients in south Egypt

AIM: To investigate characteristics of hepatitis B virus (HBV) implicated in HBV reactivation in patients with hematological malignancies receiving immunosuppressive therapy.

METHODS: Serum samples were collected from 53 patients with hematological malignancies negative for hepatitis B surface antigen (HBsAg) before the start of and throughout the chemotherapy course. HBV reactivation was diagnosed when the HBsAg status changed from negative to positive after the initiation of chemotherapy and/or when HBV DNA was detected by real-time detection polymerase chain reaction (RTD-PCR). For detecting the serological markers of HBV infection, HBsAg as well as antibodies to the core antigen (anti-HBc) and to the surface antigen were measured in the sera by CEIA. Nucleic acids were extracted from sera, and HBV DNA sequences spanning the S gene were amplified by RTD-PCR. The extracted DNA was further subjected to PCR to amplify the complete genome as well as the specific genomic sequences bearing the enhancer II/core promoter/pre-core/core regions (nt 1628-2364). Amplicons were sequenced directly.

RESULTS: Thirty-five (66%) of the 53 HBsAg-negative patients were found to be negative serologically for anti-HBc, and the remaining 18 (34%) patients were positive for anti-HBc. Five of the 53 (9.4%) patients with hematologic malignancies experienced HBV reactivation. Genotype D1 was detected in all five patients. Four types of mutant strains were detected in the S gene product of HBV strains and were isolated from 3 patients with HBV reactivation: T/S120, L143, and I126. HBV DNA was detected in the pretreatment HBsAg-negative samples in one of the five patients with HBV reactivation. In this patient, sequences encompassing the HBV full genome obtained from sera before the start of chemotherapy and at the time of de novo HBV hepatitis were detected and it showed 100% homology. Furthermore, in the phylogenetic tree, the sequences were clustered together, thereby indicating that this patient developed reactivation from an occult HBV infection.

CONCLUSION: Past infection with HBV is a risk factor for HBV reactivation in Egypt. Mandatory anti-HBc screening prior to chemotherapy in patients with hematological malignancies is recommended.

Low prevalence of HBV DNA in the liver allograft from anti-HBc-positive donors: a single-center experience

Allografts from donors positive for antibody to hepatitis B core antigen (anti-HBc(+)) can transmit hepatitis B virus (HBV) to the recipients. We aimed to study the prevalence of HBV DNA in liver allografts from anti-HBc(+) donors. Between January 2003 and December 2008, this retrospective study identified 18 patients who received a liver from an anti-HBc(+) donor. Pre- and post-transplantation HBV serology and serum HBV DNA level of the study subjects were reviewed. DNA extracted from liver biopsy tissue was used for PCR assay. Immunohistochemistry was also performed to determine viral protein expression. We observed a low prevalence of HBV DNA in allografts from anti-HBc(+) donors even among patients who did not receive prophylaxis. Only one of 18 patients had detectable HBV DNA in the liver allograft. This recipient was seronegative for HBV before transplantation and did not receive prophylaxis after transplantation, and developed de novo hepatitis B. Of the five patients who were positive for both antibody to hepatitis B surface antigen and anti-HBc before transplantation and did not receive prophylaxis after transplantation, none developed HBV infection. Prophylaxis for HBV is important for seronegative recipients receiving a liver from an anti-HBc(+) donor. Such prophylaxis may not be necessary for recipients who do not have detectable HBV DNA in the liver allograft.

Liver transplant from Anti-HBc-positive, HBsAg-negative donor into HBsAg-negative recipient: is it safe? A systematic review of the literature

INTRODUCTION

After liver transplant (LT) from Anti-HBc+/HBsAg- donors into HBsAg- recipients, transmission of hepatitis B virus (HBV) may occur (de novo HBV infection). This study analyzes the incidence of de novo HBV infection in HBsAg- recipients of Anti-HBc+/HBsAg- LT with respect to: (i) the recipients' HBV serology and (ii) the type of preventive therapy adopted.

METHODS

A systematic review of the literature using the electronic database Medline.

RESULTS

Five hundred and fifty-two LT in 36 articles were selected. Lamivudine, Hepatitis B immune globulin (HBIG), revaccination, and combined therapies were employed in multiple strategies as preventive interventions. Naïve recipients had a high risk of de novo HBV infection, with smaller incidences when HBIG and lamivudine were used, either alone or in association. Vaccinated recipients or those with isolated hepatitis B core antibodies (Anti-HBc) and previous HBV infection had lower risks of viral transmission, additionally reduced by any prophylaxis adoption.

DISCUSSION

LT from Anti-HBc+/HBsAg- donors into HBsAg- recipients is apparently safe, as long as the recipient is vaccinated or presents an isolated Anti-HBc or previous HBV infection and some prophylaxis is employed. Currently lamivudine seems the best alternative; other nucleoside analogs and revaccination strategies should be considered in future studies. Follow-up and preventive therapies should be maintained for five yr or preferably throughout the recipients' life span.

Current use of hepatitis B immune globulin for prevention of de novo hepatitis B in recipients receiving anti-HBc-positive livers

Livers from donors positive for antibody against anti-HBc can potentially transmit de novo hepatitis B (DNH) to their recipients. Despite a good outcome, prophylaxis is usually offered to such recipients. There is no consensus on the standard prophylactic regimen and hence prophylaxis varies among different transplant centres. Nonetheless, hepatitis B immune globulin (HBIG) is considered the mainstay of such prophylaxis, either alone or in combination with an oral antiviral treatment. We aim to provide a concise review of the current use of HBIG in prevention of DNH. We also address a few important questions regarding HBIG use.

Epidemiology of HBV infection in Asian blood donors: Emphasis on occult HBV infection and the role of NAT

Hepatitis B virus (HBV) infection is endemic in many Asian countries. Among many transmission routes, transfusion is the one that should be prevented. The first major success in enhancing transfusion safety came with the implementation of hepatitis B surface antigen (HBsAg) in the early 1970s. However, the studies quoted in this review demonstrate that transmission by blood components negative for HBsAg can still occur in the acute phase of infection during the seronegative window period, or during chronic stages of infection (i.c. "occult" HBV infection, OHB). OHB is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg, with or without any HBV antibodies. Because of limitations in current blood screening practices, OHB is an overlooked source of HBV transmission. For policy development on screening for HBV infection in blood donors, it would be useful to assess the relative contribution of the above two sources of transfusion-transmitted HBV infection from HBsAg-negative donations. New screening policy should be evaluated on the basis of available data or newly designed studies. While anti-HBc screening can climinate residual risk of occult HBV transmission by transfusion in low-endemic areas, it would not be practical in most parts of the world where the prevalence of anti-HBc is >10% as too many otherwise healthy donors will be ineligible. On the contrary, studies mentioned in this paper indicate that nucleic acid amplification test (NAT) or new HBsAg tests of enhanced sensitivity would be effective in the screening of blood donors for OHB in highly endemic countries. However, the cost-effectiveness of blood screening tests is a major concern in Asia. We therefore have systemically reviewed the literature on prevalence and infectivity of OHB in Asian countries and the possible role of NAT for identifying blood donors in the pre-HBsAg window phase or in later stages of OHB.

Frequent detection of hepatitis B core antibodies in heart transplant recipients without preceding hepatitis B infection

It is unclear whether heart donors positive for hepatitis B core antibodies (anti-HBc) can transfer hepatitis B virus (HBV) infection to immunosuppressed heart recipients, or whether passive transfer of anti-HBc simulates a hepatitis B infection. Therefore, we performed a case-controlled study in 46 heart recipients who all tested negative for hepatitis B antigen (HbsAg), antiHBc, and hepatitis B surface antibodies before heart transplantation. Twenty-three patients (group 1) received hearts from anti-HBc-positive donors, while 23 other patients (group 2) received hearts from anti-HBc-negative donors. After heart transplantation, anti-HBc were present in 65.0% of blood samples among group 1 and 47.8% of the blood samples among group 2 (P > .05). HbsAg was undetectable in blood samples of all patients of both study groups. The immunoglobulin preparation that we regularly use for immune suppression immediately after heart transplantation contained a relatively high concentration of anti-Hbc antibodies. The nearly identical presence of anti-HBc in both study groups indicated that passive transfer via immunoglobulin preparations rather than HBV infection is the cause for the anti-HBc detected in heart recipients. Since only a small volume of blood is transferred with the donor heart, it seems to be rather unlikely that the donor heart might be the source of anti-HBc. In summary, we observed no evidence for HBV infection in those heart recipients who received organs from anti-HBc-positive donors. Moreover, our data demonstrated that the presence of anti-HBc in heart recipients frequently occurs but does not necessarily indicate a preceding HBV infection.

Occult hepatitis B virus infection: implications in transfusion

Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.

Successful pregnancy in a liver transplant recipient treated with lamivudine for de novo hepatitis B in the graft

Pregnancy is often successful after liver transplantation, despite the potentially toxic effects of immunosuppressive drug therapy. Liver transplant recipients with recurrent hepatitis C or hepatitis B nonetheless appear to be at risk of a worse graft function in the event of pregnancy, and antiviral drugs are generally contraindicated in pregnancy because of their teratogenic effects. A 33-year-old woman had undergone liver transplantation for Caroli's disease 6 years previously. Two years later the patient experienced de novo HBV hepatitis. Lamivudine treatment (100 mg/day) was started and clearance of HBsAg was documented 1 year later. Four years after starting antiviral treatment the patient became pregnant, despite of the risk of teratogenic effects; lamivudine, cyclosporine and azathioprine were not discontinued for risk of break-through hepatitis and acute or chronic rejection. The course of gestation was uneventful and caesarean section was performed after 36 weeks. The newborn infant was a healthy male weighing 3,080 g and measuring 50 cm.

Persistence of isolated antibodies to woodchuck hepatitis virus core antigen is indicative of occult infection

Antibodies against virus nucleocapsid (anticore) normally accompany hepadnaviral hepatitis but they may also occur in the absence of symptoms and other serological indicators of the infection. This situation can be encountered following a clinically and serologically unapparent exposure to hepatitis B virus (HBV) or after recovery from hepatitis B. In this study, woodchucks inoculated with woodchuck hepatitis virus (WHV) were investigated to determine the relationship between anticore detection and the molecular status of virus replication in a primary WHV surface antigen (WHsAg)-negative infection or long-after resolution of WHV hepatitis. Serial, parallel samples of sera, peripheral blood mononuclear cells (PBMC) and liver tissue, collected for more than 5 years after inoculation with virus, were examined for WHV DNA by highly sensitive polymerase chain reaction (PCR)/nucleic acid hybridization assays. Sera were also tested for WHV DNA after DNase treatment and for WHV DNA and WHsAg after concentration in sucrose. Liver and PBMC were examined for WHV covalently closed circular DNA and viral RNA transcripts by PCR-based techniques to assess virus replication status. The study showed that anticore antibodies existing in the absence of other serological markers are a reliable indicator of occult WHV infection. This state can be accompanied by traces of circulating particles behaving as intact virions and by intermittent minimal-to-mild liver inflammation. In conclusion, the long-term presence of anticore antibodies alone is a consequence of sustained restimulation of the immune system by virus nucleocapsid produced during low-level hepadnaviral assembly.

Occult hepatitis B virus infection

The detection of HBV DNA without HBsAg with or without the presence of HBV antibodies outside the acute phase window period defines occult HBV infection. This condition has been described in hepatocellular carcinoma (HCC), chronic hepatitis B, healthy HBV carriage and recovered infection, chronic hepatitis C and individuals without serological markers of HBV. The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. Occult HBV in blood donors has a wide range of potential origins within the natural history of the infection. It may originate from recovered infections with anti-HBs and persistent, low-level, viral replication, escape mutants undetected by the HBsAg assays or healthy chronic carriage. The last situation is mostly found with anti-HBc only. Over time, antibody markers may become undetectable leaving HBV DNA as the only marker of the infection. In all cases, the viral load is low, mostly below 10(4) IU/ml, often below 100 IU/ml. At these levels, nucleic acid testing (NAT) in pools is likely to be largely ineffective. Is occult HBV transmissible by transfusion? Carriers of anti-HBs or anti-HBc only were shown infectious in immunosuppressed organ or bone marrow transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components are infectious, even in low titre. Donations carrying anti-HBc only and HBV DNA can be infectious and this is a threat where anti-HBc is not screened. Anti-HBc screening identifies most occult HBV infection but not all. HBV NAT needs either extreme sensitivity or to be performed on individual donations to eliminate HBV DNA-containing units.

Does lamivudine prophylaxis eradicate persistent HBV DNA from allografts derived from anti-HBc-positive donors?

Transplantation of livers from anti-hepatitis B core antibody (anti-HBc)-positive donors into anti-HBc-negative recipients is associated with a high rate of viral transmission. We report a prophylaxis regimen based on virologic evaluation of the donor. Liver and serum from hepatitis B surface antigen (HBsAg)-negative, anti-HBc-positive donors were evaluated by polymerase chain reaction (PCR) for hepatitis B virus (HBV) DNA. All anti-HBc-negative recipients were given a single dose of hepatitis B immunoglobulin (HBIG) during the anhepatic phase of transplantation and were placed on maintenance lamivudine monotherapy. Recipients were followed up longitudinally monitoring intrahepatic HBV DNA as well as serologic HBsAg and HBV DNA by PCR. Between January 1999 and August 2001, 14 anti-HBc-negative recipients received liver transplants from anti-HBc-positive donors. All donor serum was negative for HBV DNA. In total, nine of 14 (64%) livers had detectable HBV DNA; 1 patient was initially PCR-negative and low levels of HBV DNA were detected in a posttransplantation liver biopsy. Mean follow-up was 33 months (range, 22 to 51), and patient and graft survival were each 93%. One case of de novo hepatitis B occurred in a patient noncompliant with lamivudine, although all other serial serum HBsAg assay results were negative. Single-dose HBIG followed by maintenance lamivudine monotherapy prevented de novo hepatitis B in compliant patients. For the cohort of compliant patients that were initially HBV DNA-positive, 7 of 8 (88%) now have undetectable virus in the hepatic allograft by PCR analysis. Nevertheless, there is no evidence to suggest that viral eradication occurs. Accordingly, all patients are maintained on continued lamivudine prophylaxis.

Nucleoside analogues and other antivirals for treatment of hepatitis B in the peritransplant period

Chronic HBV infection is a common cause of advanced liver disease that is associated with substantial mortality. Furthermore, chronic hepatitis B was historically a controversial indication for liver transplantation because of a low post-transplant survival, with graft infection being the major contributor to adverse outcomes. The initial use of hepatitis B immune globulin as prophylaxis, followed later by combined therapy with lamivudine, markedly reduced viral recurrence and improved the survival of patients transplanted for acute or chronic hepatitis B with liver failure. Lamivudine alone can also be used for long-term prophylaxis against de novo HBV infection that can be transmitted by organs from donors positive for anti-HBc or anti-HBs. When used in patients with decompensated chronic hepatitis B with cirrhosis, lamivudine has been shown to improve clinical manifestations, prolong pretransplant survival, and defer, or even obviate, the need for transplantation. Despite prophylaxis, viral mutations with breakthrough reinfection may occur and lead to liver failure. The recently approved adefovir dipivoxil, which is active against lamivudine-resistant mutation, and other nucleoside analogs that are in various phases of development, offer hope as rescue therapy for viral recurrence. Other therapeutic alternatives in the future may include gene therapy and immune interventions.

Use of liver grafts from donors positive for antihepatitis B-core antibody (anti-HBc) in the era of prophylaxis with hepatitis-B immunoglobulin and lamivudine

BACKGROUND

The increasing demand for transplantation has resulted in a trend toward using virologically compromised donors. We reviewed our experience with liver grafts from hepatitis-B surface antigen (HBsAg)(-), antibody to core antigen (anti-HBc)(+) donors.

METHODS

Sixty-two liver transplants using HBsAg(-), anti-HBc(+) donors were studied. The decision to use prophylaxis was based on the presence or absence of donor and recipient risk factors for posttransplant hepatitis-B virus (HBV) transmission or reinfection. If the donor or recipient showed positive HBVDNA, hepatitis-B immunoglobulin (HBIg) and lamivudine were used. If both donor and recipient HBVDNA were negative, a choice between lamivudine and no prophylaxis was made on the basis of presence or absence of HBsAg and antibody to the surface antigen (anti-HBs) in the recipient.

RESULTS

No death or graft loss could be ascribed to HBV. Mild HBV infection occurred in two patients who were not taking the recommended prophylaxis. Among the other 60 patients, 1 showed positive e antigen (HBeAg) early after transplantation, and 2 (1 with recurrent cancer, 1 with HIV infection) showed HBsAg(+). None of the three patients had any other evidence of HBV infection. Forty-seven patients underwent liver biopsies. Changes consistent with hepatitis were observed in 26, and 24 had HCV infection; immunostains for HBV antigens were negative in all cases, and 7 showed positive HBVDNA.

CONCLUSIONS

A selective protocol based on donor and recipient risk factors for post-liver transplant HBV infection can prevent hepatitis-B infection and avoid unnecessary administration of antiviral prophylaxis in recipients of HBsAg(-), anti-HBc(+) liver allografts.

Frequency and load of hepatitis B virus DNA in first-time blood donors with antibodies to hepatitis B core antigen

The objective of this study was to determine the frequency and load of hepatitis B virus (HBV) DNA in anti-HBc-positive first-time blood donors; it was designed to contribute to determining whether anti-HBc screening of blood donations might reduce the residual risk of posttransfusion HBV infection. A total of 14 251 first-time blood donors were tested for anti-HBc using a microparticle enzyme immunoassay; positive results were confirmed by a second enzyme-linked immunosorbent assay (ELISA). For the detection of HBV DNA from plasma samples, we developed a novel and highly sensitive real-time polymerase chain reaction (PCR) assay. The 95% detection limit of the method amounted to 27.8 IU/mL, consistent with the World Health Organization (WHO) international standard for HBV DNA. A total of 216 blood donors (1.52%) tested anti-HBc-positive in both tests, and 205 of them (16 HBsAg(+), 189 HBsAg(-)) were tested for HBV DNA. In 14 (87.5%) of the HBsAg-positive blood donors, HBV DNA was repeatedly detected, and in 3 (1.59%) of the HBsAg-negative donors, HBV DNA was also found repeatedly. In the 3 HBV DNA-positive, HBsAg-negative cases, anti-HBe and anti-HBs (> 100 IU/L) were also detectable. HBV DNA in HBsAg-negative as well as HBsAg-positive samples was seen at a low level. Thus, HBV DNA is sometimes found in HBsAg-negative, anti-HBc-positive, and anti-HBs-positive donors. Retrospective studies on regular blood donors and recipients are necessary to determine the infection rate due to those donations. Routine anti-HBc screening of blood donations could probably prevent some transfusion-transmitted HBV infections.

In vitro infection of human peripheral blood mononuclear cells by a defective hepatitis B virus with a deletion in the PreS1 region of the viral genome

Previously, we identified a defective hepatitis B virus (HBV) which contains a 183 nucleotide deletion in the PreS1 region of the viral genome affecting the S gene promoter in sera from hepatitis B surface antigen (HBsAg)-negative patients with serum HBV-DNA. The aim of this study was to analyse the infectivity of this mutant. Peripheral blood mononuclear cells (PBMC) from a healthy donor were incubated with serum samples from 2 HBsAg-negative patients with serum HBV-DNA (infected with wild-type and deletion mutant HBV), from an HBsAg carrier (infected with wild-type HBV) and from a healthy donor. After 1 week, HBV-DNA was detected by polymerase chain reaction (PCR) in all supernatants and cells incubated with the HBV-DNA-positive inocula. DNase and trypsin pretreatment confirmed intracellular localization of HBV-DNA in cells. HBV-RNA and covalently closed circular HBV-DNA were also detected in PBMC, indicating that the viral DNA infecting these cells was transcriptionally active. Deletion mutant and wild-type HBV were detected in the supernatants and cells infected with the two HBsAg-negative sera, while only wild-type HBV was detected in the supernatant and cells incubated with the serum from the HBsAg-carrier. In conclusion, this HBV deletion mutant can infect, replicate and release viral particles in in vitro infected PBMC.

Clinical characteristics of hepatitis B core antibody-positive hepatocellular carcinoma

The pathology and prognosis of hepatitis B surface antigen (HBsAg)-positive hepatocellular carcinoma (HCC) and hepatitis C virus antibody (HCVAb)-positive HCC is well documented. However, patients with HBsAg-negative/hepatitis B core antibody (HBcAb)-positive HCC are included with non-B non-C disease and have been characterized independently. A series of 125 patients who had undergone hepatectomy for HCC were divided into three groups and compared. The HBsAg group comprised 25 HBsAg-positive patients, the HCV group comprised 70 HCVAb-positive patients, and the HBcAb group comprised 22 HBcAb-positive/HBsAg-negative patients. Eight patients of negative virus markers were excluded in this study. Tumors were larger in the HBcAb group (6.2 cm) than in the HBsAg (4.4 cm) and HCV (3.7 cm) groups. Disease-free 1-, 3-, and 5-year survival rates were, respectively, 75.0%, 57.1%, and 57.1% in the HBcAb group; 60.9%, 41.8%, and 41.8% in the HBsAg group; and 88.0%, 54.0%, and 37.8% in the HCV group. HBcAb-positive HCC patients had larger tumors, but their prognosis was relatively good. Although HBsAg and HCVAb are used for conventional screening of patients with hepatic disorders, we believe that screening is also necessary in patients with positive HBcAb titers for early detection of HCC.

Impact of anti-hepatitis Bc-positive grafts on the outcome of liver transplantation for HBV-related cirrhosis

BACKGROUND

The present scarcity of organ donors requires consideration of grafts from sources not previously used. Several studies have addressed the use of grafts from donors who have antibodies to the hepatitis B core antigen (anti-HBc+). The aim of this study was to evaluate the impact of the use of anti-HBc+ grafts in patients transplanted for hepatitis B virus (HBV)-related cirrhosis.

METHODS

Recipients of first hepatic transplants from donors with antibodies to HBV were identified retrospectively. All patients who had serology suggestive of active HBV and were negative for hepatitis C and D were included in the analysis. The Kaplan-Meier method was used to assess the actuarial recurrence-free survival on patients with graft survival longer than 1.5 months. The stepwise Cox regression model was used to identify independent predictors of HBV recurrence.

RESULTS

One thousand seven hundred seventeen first liver transplants were performed at the Thomas E. Starzl Transplantation Institute from September 1, 1990, to December 31, 1999. HBV was the cause of cirrhosis in 112 patients (6.5%). Thirty-three patients had coexistent viral infection (23 HCV and 10 HDV). Fourteen donors (17.2%) were positive for HBV markers, with nine anti-HBc+ and with five both anti-HBc+ and anti-HB surface-positive; of these, 13 anti-HBc+ organ recipients had long-term survival. Nine (69.2%) of these cases were reinfected versus 20 (35.7%) in the group that received grafts from HBV- donors (P<0.05, Fisher's exact test). The mean time to reinfection was shorter in the anti-HBc+ group (2.9 yr vs. 6.4 yr, P<0.005). There were no statistical differences in graft or patient survival between the two groups. HBV prophylaxis with combined lamivudine and hepatitis B immunoglobulin (HBIG) significantly reduced the reinfection rate (P<0.03). Hepatitis Be (Hbe) antigen-positive recipients trended to faster reinfection (not significant). Cox regression analysis revealed that both anti-HBc graft donor status (RR, 2.796; P=0.020) and combination of lamivudine/HBIG (RR, 0.249; P=0.021) are independently associated with reinfection.

CONCLUSIONS

The use of anti-HBc+ liver grafts does not affect graft or patient survival. However, patients who receive these organs are 2.5 times more likely to develop HBV recurrence. Lamivudine and HBIG combination decreases HBV recurrence 4-fold.

Transplantation of livers from hbc Ab positive donors into HBc Ab negative recipients: a strategy and preliminary results

Here we describe a strategy for using livers from hepatitis B core antibody (anti-HBc) positive donors in anti-HBc negative recipients and report our preliminary results. Adult anti-HBc negative recipients were immunized against hepatitis B virus (HBV) prior to transplantation. Liver biopsies from anti-HBc positive, HBs Ag negative donors were performed at the time of procurement to rule out acute hepatitis or chronic liver disease. Donor serum and liver samples were collected for HBV DNA analysis by PCR. Recipients were given HBIG (10000 units, i.v.) during the anhepatic phase of transplantation. Patients were treated with lamivudine (150 mg) beginning on postoperative day (POD) 1. If HBV DNA was not detected in either donor liver or serum by PCR, recipient antiviral therapy was stopped. If donor liver and serum were positive for HBV DNA by PCR, the recipient was maintained on combination lamivudine and HBIG therapy. If HBV DNA was detected in donor liver but not in donor serum, the patient was managed on lamivudine therapy alone. Between February 1999 and June 2000, six anti-HBc negative recipients received liver transplants from anti-HBc positive donors. PCR analysis of serum from the six donors was negative for HBV DNA in each, while donor liver PCR analysis was positive in five of six for HBV DNA. Accordingly, all patients were given HBIG in the anhepatic phase of transplantation and five of six were maintained on daily lamivudine therapy. Follow-up periods have ranged from 2 to 18 months. There has been no emergence of de novo hepatitis B. Serial serum HBs Ag and HBV DNA assays have all proven negative. Moreover, while on lamivudine therapy, 2 patients now have undetectable HBV DNA in hepatic allograft biopsies by PCR analysis. Our strategy for using livers from anti-HBc donors has yielded promising initial results. De novo hepatitis B has not occurred and our data suggest residual hepatitis B virus may be eradicated in recipients maintained on lamivudine therapy.

A concise update on the status of liver transplantation for hepatitis B virus: the challenges in 2002

Significant improvements in both patient and graft survival after orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related liver failure have been made during the last decade. Recurrence of HBV infection has decreased, even in high-risk patients. Despite ongoing progress, challenges remain for the next millennium, including the determination of cost-effective dosing strategies, treatment of HBV infection in liver transplant recipients, and ramifications of the use of new antiviral agents, specifically, the appearance of resistant strains. This review summarizes the relevant history of OLT for chronic viral hepatitis B, details accepted preventive and therapeutic treatments, and discusses ongoing experimental trials. Emphasis also is placed on new approaches in transplantation as they impact on the care of HBV-infected patients.

Isolated anti-HBc in chronic hepatitis C predicts a poor response to interferon treatment

The sustained response to interferon-alpha treatment was evaluated in 147 anti-HCV/HCV-RNA-positive, HBsAg-negative, chronic hepatitis patients, according to HCV genotypes and the presence or absence of anti-HBs and anti-HBc. These patients had been included in a controlled study on the safety, tolerability, and efficacy of three types of interferon-alpha given at a dose of 3 MU three times weekly for 52 weeks. One hundred and two patients had HCV genotype 1, 42 a non-1 HCV genotype and 3 multiple HCV genotypes; 46 were anti-HBs and anti-HBc negative (group A), 50 anti-HBs and anti-HBc positive (group B), and 51 anti-HBs negative and anti-HBc positive ("isolated" anti-HBc, group C). Serum HBV-DNA was detected by polymerase chain reaction in 15 of the 51 (29.4%) patients in group C and in none of those in groups A or B. The Sustained Response rate was higher in patients with a non-1 HCV genotype than those with HCV genotype 1 (31% vs. 17.7%, P > 0.1). Fewer patients in group C showed a sustained response than in group A or group B (7.8% vs. 30.4%, P = 0.009 and 7.8% vs 28%, P = 0.017, respectively). Moreover, the sustained response rate was high in patients with a non-1 genotype, both in group A (42.8%) and in group B (42.8%), intermediate in patients with HCV genotype 1 (23.3% in group A and 22.2% in group B) and low in group C, irrespective of HCV genotype (8.3% for genotype 1 and 7.1% for other genotypes). The data indicate that patients with HCV chronic hepatitis and isolated anti-HBc show a poor response to IFN-alpha, irrespective of the HCV genotype.

Long-term clinical impact of occult hepatitis B virus infection in chronic hepatitis B patients

BACKGROUND/AIMS

Long-term clinical outcomes of occult hepatitis B virus (HBV) infection were studied.

METHODS

Fifteen chronic hepatitis B patients were monitored for a median of 4.4 years (range 0.9-15.3) after hepatitis B surface antigen (HBsAg) seroclearance. Serum HBV DNA was measured by real-time detection polymerase chain reaction. Thirteen patients underwent liver biopsies at the end of follow-up and liver histology was evaluated by Ishak score. Liver HBV DNA was also measured for 12 patients.

RESULTS

At the end of follow-up, HBV viremia was absent in 13 (87%) patients, and antibody titers to hepatitis B core antigen showed an inverse correlation with time from HBsAg seroclearance (r=-0.554; P=0.0040). However, all patients retained liver HBV DNA and tested positive for the covalently closed circular HBV DNA replicative intermediate. The hepatic HBV DNA loads had no relation to liver histology. Paired biopsies from 11 patients disclosed that each necroinflammatory score significantly improved after HBsAg seroclearance. Amelioration of liver fibrosis was also evident in eight (73%) patients (P=0.0391 by signed rank test).

CONCLUSIONS

A long-standing but strongly suppressed HBV infection may confer histological amelioration after HBsAg seroclearance.

State of HBV DNA in HBsAg-negative, anti-HCV-positive hepatocellular carcinoma: existence of HBV DNA possibly as nonintegrated form with analysis by Alu-HBV DNA PCR and conventional HBV PCR

The role of hepatitis B virus (HBV) in carcinogenesis of hepatitis B surface antigen (HBsAg)-negative, anti-hepatitis C virus (anti-HCV)-positive hepatocellular carcinoma (HCC) remains unknown. To investigate the state of HBV DNA in such HCC, HBV DNA was examined by polymerase chain reaction (PCR) between HBV DNA and human Alu sequence (HBV-Alu PCR), which could detect integrated form of HBV DNA only, and by conventional HBV PCR, which could detect both integrated and episomal forms of HBV DNA. In all the 17 HBsAg-positive HCC, HBV DNA was detected by both HBV-Alu PCR method and conventional HBV PCR method. By contrast, in HBsAg-negative, anti-HCV-positive cases, HBV DNA was detected in 10 of 21 (47.6%) by conventional HBV PCR and in none of 21 (0%) by HBV-Alu PCR method. Thus, integrated form of HBV DNA was not found in most HbsAg-negative, anti-HCV-positive HCC in the current study. The role of episomal form of HBV DNA requires further investigation of its involvement in the process of the development of HBsAg-negative, anti-HCV-positive HCC.

Transmission of hepatitis B infection from hepatitis B core antibody--positive liver allografts is prevented by lamivudine therapy

Donor shortage has led to the use of hepatitis B core antibody (anti-HBc)--positive (anti-HBc(+)) liver allografts for patients in need of relatively urgent orthotopic liver transplantation (OLT). Because anti-HBc(+) allografts transmit hepatitis B virus (HBV) infection at a high rate, effective prophylaxis is required. We assessed the effectiveness of lamivudine in preventing HBV transmission by anti-HBc(+) allografts. Between March 1996 and March 2000 at Cedars-Sinai Medical Center (Los Angeles, CA), 15 of 169 patients (8.9%) received liver allografts from anti-HBc(+) donors. Six patients were hepatitis B surface antigen (HBsAg)(+) (group 1), and 9 patients were HBsAg negative (HBsAg(-); group 2) before OLT. All patients were administered lamivudine, 100 or 150 mg/d, orally after OLT. Patients who were HBsAg(+) before OLT also were administered hepatitis B immunoglobulin (HBIG) prophylaxis. Hepatitis B serological tests were performed on all patients, and HBV DNA was determined in liver tissues in 10 patients. All 15 patients remained HBsAg(-) at their last follow-up 2 to 40 months (mean, 17 months) post-OLT. All patients in group 1 had antibody to HBsAg (anti-HBs) titers greater than 250 mIU/mL post-OLT (mean follow-up, 20 months; range, 7 to 40 months). Of the 2 patients in group 1 who underwent liver biopsy after OLT, 1 patient had detectable hepatic HBV DNA despite being anti-HBs(+) and HBsAg(-). Among the patients in group 2, none acquired anti-HBc or HBsAg. Hepatic HBV DNA was undetectable in the 7 patients in group 2 who underwent liver biopsy after OLT. Anti-HBc(+) allografts can be safely used in patients who undergo OLT for chronic hepatitis B and susceptible transplant recipients if prophylaxis with combination HBIG and lamivudine or lamividine alone is administered after OLT, respectively. However, more data are needed to determine the efficacy of lamivudine monotherapy in preventing transmission of HBV infection from anti-HBc(+) liver allografts to susceptible recipients.

High frequency of circulating HBcAg-specific CD8 T cells in hepatitis B infection: a flow cytometric analysis

Viral antigen-specific T cells are important for virus elimination. We studied the hepatitis B virus (HBV)-specific T cell response using flow cytometry. Three phases of HBV infection were studied: Group A, HBeAg (+) chronic hepatitis; Group B, HBeAb (+) HBV carrier after seroconversion; and Group C, HBsAb (+) phase. Peripheral T cells were incubated with recombinant HB core antigen (HBcAg), and intracytoplasmic cytokines were analysed by flow cytometry. HBcAg-specific CD4 and CD8 T cells were identified in all three groups and the number of IFN-gamma-positive T cells was greater than TNF-alpha-positive T cells. The frequency of IFN-gamma-positive CD4 and CD8 T cells was highest in Group C, compared with Groups A and B. No significant difference in the HBcAg-specific T cell response was observed between Group A and Group B. The HBcAg-specific CD8 T cell response was diminished by CD4 depletion, addition of antibody against human leucocyte antigen (HLA) class I, class II or CD40L. Cytokine-positive CD8 T cells without HBcAg stimulation were present at a high frequency (7 of 13 cases) in Group B, but were rare in other groups. HBcAg-specific T cells can be detected at high frequency by a sensitive flow cytometric analysis, and these cells are important for controlling HBV replication.

Vaccination against hepatitis B in patients with chronic liver disease awaiting liver transplantation

BACKGROUND

Most transplant centers in the United States immunize patients awaiting liver transplantation against hepatitis B to prevent acquisition of hepatitis B through transplantation (de novo hepatitis B). A recent study showed that only 16% of patients with cirrhosis awaiting liver transplantation responded to single-dose recombinant vaccine.

METHODS

We studied the immunogenicity of double-dose recombinant vaccine in patients with cirrhosis awaiting liver transplantation.

RESULTS

Over a 4-year period (January 1994 to December 1997), 140 patients with cirrhosis without past or current hepatitis B infection were given double-dose recombinant vaccine (40 microg of Engerix B; SmithKline Beecham, Philadelphia, PA) at 0, 1 to 2, and 2 to 4 months. Hepatitis B surface antibody (HBsAb) was measured 1 to 3 months after completing vaccination. The response rate was 37%. However, HBsAb titers became undetectable in 35% of the responders during the post-transplant follow-up period. One hundred and thirty-seven patients underwent 144 liver transplantation procedures during the study period, and 3 patients developed de novo hepatitis B (2.2%). Livers transplanted from hepatitis B core antibody (HBcAb)-positive donors was the source of de novo hepatitis B in all cases. Two of the 3 patients who developed de novo hepatitis B were immunized before transplantation and one of them was a responder.

CONCLUSION

Although the response rate to double-dose recombinant vaccines is higher than the previously reported response to single-dose vaccine, it still is less than optimal.

Persistence of infectious hepadnavirus in the offspring of woodchuck mothers recovered from viral hepatitis

Mother-to-child transmission is an important route for hepatitis B virus (HBV) dissemination. It has been established that HBV traces persist for years after complete clinical recovery from hepatitis B. Similarly, resolution of hepatitis caused by HBV-related woodchuck hepatitis virus (WHV) is followed by occult lifelong carriage of pathogenic virus. In this study, we documented that WHV persisting after termination of acute hepatitis is transmittable to newborns as an asymptomatic long-term infection. All 11 offspring from 4 dams studied carried transcriptionally active WHV genomes for 3.5 years after birth without immunovirological markers of infection. WHV genomes and mRNA were detected both in the liver and lymphoid tissue in the majority of offspring; WHV covalently closed circular DNA was detected in some samples. In 4 offspring, however, the virus was restricted to the lymphatic system. In the circulation, WHV DNA-reactive particles were DNase resistant and of comparable size and density to complete virions. Importantly, the virus in offspring with or without hepatic WHV DNA expression was infectious to WHV-naive woodchucks. Finally, offspring challenged with WHV were not protected against reinfection. These findings show that mothers with occult hepadnaviral carriage transmit pathogenic virus to their offspring, inducing a persistent infection invariably within the lymphatic system but not always in the liver.

Occult lifelong persistence of infectious hepadnavirus and residual liver inflammation in woodchucks convalescent from acute viral hepatitis

Traces of hepatitis B virus (HBV) genome can persist for years following recovery from hepatitis B. To determine overall duration, molecular characteristics, and pathological implications of this serologically undetectable form of hepadnaviral carriage, we have analyzed the expression of transcriptionally active virus genomes, their infectivity, and examined liver alterations during the natural lifespan of woodchucks convalescent from acute infection with HBV- related woodchuck hepatitis virus (WHV). In this study, we document lifelong persistence of scanty amounts of replicating virus both in the liver and lymphatic system after spontaneous resolution of an episode of experimental hepadnaviral hepatitis. Antibodies to virus nucleocapsid (core) were found to be the most reliable immunovirological marker coexisting with occult infection. In the majority of convalescent woodchucks, serial liver biopsies showed protracted minimal to mild necroinflammation with periods of normal morphology; however, hepatocellular carcinoma (HCC) ultimately developed in 2 of 9 animals studied. Inocula derived from lymphoid cells of convalescent animals induced classical acute hepatitis in virus-naive woodchucks that progressed to chronic hepatitis and HCC in 1 of the animals, demonstrating infectivity and pathogenic competence of the carried virus. Our results reveal that low levels of infectious WHV and residual hepatic inflammation usually continue for life after resolution of hepatitis and that this recovery does not avert HCC development. They also demonstrate that, in addition to the liver, the lymphatic system is the site of the occult lifelong maintenance of replicating hepadnavirus.

Molecular basis for persistent hepatitis B virus infection in the liver after clearance of serum hepatitis B surface antigen

Hepatitis B virus (HBV) DNA has been detected by polymerase chain reaction (PCR) in the liver of patients with resolved chronic HBV infection and sustained clearance of hepatitis B surface antigen (HBsAg) from serum. However, it is unknown whether the virus is transcriptionally active at this time or if the covalently closed circular (CCC) replicative intermediate of HBV DNA can still be detected. Therefore, hepatic nucleic acid extracts from seven patients who had cleared serum HBsAg were assessed by (PCR) for either reverse-transcribed HBV RNA, or an intact direct repeat region of the HBV genome indicative of the CCC replicative intermediate of HBV DNA. HBV transcripts were detected in four of seven patients in the study group, whereas an intact direct repeat region of the HBV genome was detected in three. Evidence for viral transcription and replication was more frequently detected in patients who had recently cleared serum HBsAg, but HBV RNA was also detected in one patient 5 years after HBsAg clearance, and an intact direct repeat region of HBV DNA was detected in another subject at nearly 4 years after resolution of disease. Therefore, hepatic HBV transcription may be associated with replicative intermediates of persistent HBV DNA in patients who have cleared HBsAg from serum, suggesting that, on occasion, HBV may not be in a latent state but undergoing low-level replication.

De novo hepatitis B infection after liver transplantation: source of disease, incidence, and impact

New-onset hepatitis B (de novo B) after liver transplantation (OLTX) is an emerging concern. The goals of our study were to determine the incidence and pattern of this infection, to attempt determination of risk factors and the role of immunosuppression, and to review its morbidity/mortality. Over a 10-year period, 1078 OLTX were performed in 956 patients at our institution. Eight hundred twenty-six patients had proven negative hepatitis B surface antigen (HBsAg) before transplantation. Among these, 14 patients (1.7%), 8 women and 6 men, ages 21-59 years (median, 42 years), developed positive HBsAg after transplantation and were defined as de novo B. In 10 of 14 patients (71%), positive HBsAg was revealed during routine annual visits, whereas 4 patients had titer verification prompted by illness. Blood product use (cryoprecipitate, fresh-frozen plasma, platelets, and packed red blood cells) during the transplant hospitalization was similar between groups. Pretransplant hepatitis C infection was more prevalent among the 14 patients with de-novo B (7 of 14, 50% v 129 of 812, 16%; P < or = 05). Hepatitis B vaccine had been given to 12 patients (86%) (but not given to 2) who developed de novo B. Incidence and severity of rejection were similar in both populations, although de novo B patients had more late rejections. Our use of immunosuppressive protocols was the same in both groups. Mean follow-up of the infected patients is 24 (5-51) months. Twelve of these 14 de novo B patients were not clinically ill, with normal or near-normal transaminase levels. One of 14 has died from complications related to hepatic artery revascularization, and another is well after repeat OLTX for biliary strictures. Half of these de novo B patients remain free from viral antigens in their transplanted liver tissue. The high percentage of positive hepatitis C patients who acquire de novo B may indicate a link between these two viral infections and potential risk factor for de novo B. The origins of this infection are most likely multifactorial, needing further study. De novo B after liver transplantation is preliminarily associated with little clinical morbidity and mortality.

Diagnostic tools in the evaluation of patients with viral hepatitis undergoing liver transplantation

Familiarity with the diagnostic parameters of viral hepatitis is imperative in the liver transplantation arena. Chronic viral hepatitis B and C are among the most common categories of end-stage liver disease. The preoperative diagnosis, determination of recurrent infection, and the assessment of antiviral therapeutic efficacy are dependent on appropriate virological testing. Furthermore, liver transplant personnel are at a high risk for parenterally transmitted viral hepatitis infection. Knowledge and understanding of the serological patterns of acute and chronic viral hepatitis, as well as recognition of the immune status for one or more of these viruses, will facilitate prevention and treatment of viral hepatitis for these health care providers.

Correlation of hepatitis virus serologic status with clinicopathologic features in patients undergoing hepatectomy for hepatocellular carcinoma

BACKGROUND

This study investigated the relationship between clinicopathologic features and various viral serologies in patients who underwent hepatectomy in the treatment of hepatocellular carcinoma (HCC).

METHODS

Two hundred two patients were allocated to four groups, according to their positivity or negativity for hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (HCVAb): Group I (HBsAg[-], HCVAb[+], n = 151), Group II (HBsAg[+], HCVAb[-], n = 27), Group III (HBsAg[-], HCVAb[-], n = 20), or Group IV (HBsAg[+], HCVAb[-], n = 4). The mean age of the HBsAg positive patients (Groups II and IV) was 10 years younger than that of the HBsAg negative patients (Groups I and III).

RESULTS

The male-to-female ratio was higher in HCVAb negative groups (II and III). The HCVAb positive groups (I and IV) had a significantly poorer hepatic reserve and smaller resections than the HCVAb negative groups. Because the tumors were more advanced (as determined by TNM staging) in Group II, the 3-year crude and disease free survival rates were lower in Group II than in Group I. However, HCVAb negative groups (II and III), when compared at 5 years with the limited subsets of patients who had tumors at earlier stages or a curative resection, had significantly better crude and disease free 5-year survival rates than the HCVAb positive group (I).

CONCLUSIONS

Clinicopathologic features differ from one another in accordance with the viral seromarkers in HCC patients. Significantly better crude and disease free survival after complete resection were promising results for patients with non-HCV-related HCC. By comparison, for patients with HCV-related HCC, the risk of intrahepatic recurrences never subsided even in later years after complete resection. Therefore, posthepatectomy follow-up management should be individualized depending on the viral serologic status of HCC patients.

De novo and apparent de novo hepatitis B virus infection after liver transplantation

BACKGROUND/AIMS

The aim of this study was to clarify the aetiology of apparent de novo HBV infection after liver transplantation.

METHODS

Twenty out of 570 HBsAg negative patients (3.5%) became HBsAg positive after transplantation and were studied. Donor and recipient sera were retrospectively tested for HBsAg, anti-HBs, anti-HBc, and HBV DNA by PCR. Donor and recipient livers were tested for HBV DNA by PCR on paraffin-embedded tissue.

RESULTS

Group 1: HBV infection of donor origin (eight patients): one donor serum was HBsAg positive, three were serum HBV DNA positive, four were liver HBV DNA positive. Group 2: reactivation of latent HBV infection (eight patients) with detection of HBV DNA in pretransplant serum (seven patients) or in native liver (one patient): three were anti-HBs positive, two anti-HBc positive, and three with fulminant hepatitis had no serological HBV markers. Group 3: undetermined origin (four patients) defined by absence of HBV DNA in pretransplant donor and/or recipient sera and liver; however, acquired infection was suspected from two anti-HBs and anti-HBc positive donors. Two patients became HBsAg negative, and five HBV DNA negative. One died from HBV-cirrhosis and two were retransplanted. In the others, the last histology showed cirrhosis (three), chronic hepatitis (nine), acute hepatitis (one), and non-specific change (four patients).

CONCLUSIONS

The prevalence of de novo HBV infection in liver transplant patients was 3.5%; the aetiology was determined in 16/20 patients: from the donor in eight, and from the recipient in eight. One should be cautious when donors or recipients are anti-HBc or both anti-HBs and anti-HBc positive.

Lamivudine prophylaxis against reinfection in liver transplantation for hepatitis B cirrhosis

BACKGROUND

Orthotopic liver transplantation in patients positive for hepatitis B virus (HBV) DNA is associated with a high reinfection rate, even with hepatitis B immunoglobulin (HBIG) prophylaxis. Nucleoside analogues that inhibit hepatitis B replication in patients with chronic hepatitis B could prevent reinfection after transplantation. The aim of this study was to analyse the efficacy and safety of prophylaxis both before and after transplantation with the nucleoside analogue lamivudine, without HBIG, in patients undergoing liver transplantation.

METHODS

17 HBsAg-positive patients with decompensated cirrhosis and previous evidence of viral replication were enrolled. 12 were HBV-DNA-positive by a signal amplification assay. Patients were treated with oral lamivudine (100 mg daily) for at least 4 weeks before transplantation and followed up for 18-90 weeks after transplantation.

FINDINGS

HBV DNA became undetectable in serum before transplantation in all HBV-DNA-positive patients. Four died before transplantation from complications of cirrhosis; one patient was withdrawn from the study because of a cerebrovascular accident. The remaining 12 patients underwent transplantation. Two patients died after transplantation (one at 3 days and one [suicide] at 20 weeks). HBV DNA reappeared in one patient with histological evidence of recurrent hepatitis (72 weeks). By week 24 the nine remaining patients had lost HBsAg and remained negative for HBV DNA.

INTERPRETATION

Lamivudine treatment may prove useful in preventing recurrence of hepatitis B after liver transplantation. The effect on survival of patients after transplantation remains to be assessed.

Long-lasting memory T cell responses following self-limited acute hepatitis B

The molecular and cellular basis of long-term T cell memory against viral antigens is still largely undefined. To characterize anti-viral protection by memory T cells against non-cytopathic viruses able to cause acute self-limited and chronic infections, such as the hepatitis B virus (HBV), we studied HLA class II restricted responses against HBV structural antigens in 17 patients with acute hepatitis B, during the acute stage of infection and 2.2 to 13 yr after clinical resolution of disease. Results indicate that: (a) significant T cell proliferative responses to HBV nucleocapsid antigens were detectable in all patients during the acute phase of infection and in 14/17 also 2-13 yr after clinical resolution of disease; b) long-lasting T cell responses were sustained by CD45RO+T cells, predominantly expressing the phenotype of recently activated cells; c) limiting dilution analysis showed that in some patients the frequency of HBV-specific T cells was comparable to that observed in the acute stage of infection and, usually, higher than in patients with chronic HBV infection; d) the same amino acid sequences were recognized by T cells in the acute and recovery phases of infection; and e) HBV-DNA was detectable by nested-PCR in approximately half of the subjects. to conclusion, our results show that vigorous anti-viral T cell responses are detectable in vitro several years after clinical recovery from acute hepatitis B. Detection of minute amounts of virus in some recovered subjects suggests that long-term maintenance of an active anti-viral T cell response could be important not only for protection against reinfection but also for keeping the persisting virus under tight control.