Active immunization to prevent de novo hepatitis B virus infection in pediatric live donor liver recipients

Adult and late adolescent complications of pediatric solid organ transplantation

BACKGROUND

There have been over 51 000 pediatric solid organ transplants since 1988 in the United States alone, leading to a growing population of long-term survivors who face complications of childhood organ failure and long-term immunosuppression.

AIMS

This is an educational review of existing literature.

RESULTS

Pediatric solid organ transplant recipients are at increased risk for risk for cardiovascular and kidney disease, skin cancers, and growth problems, though the severity of impact may vary by organ type. Pediatric recipients often are able to complete schooling, maintain a job, and form family and social networks in adulthood, though at somewhat lower rates than the general population, but face additional challenges related to neurocognitive deficits, mental health disorders, and discrimination.

CONCLUSIONS

Transplant centers and research programs should expand their focus to include long-term well-being. Increased collaboration between pediatric and adult transplant specialists will be necessary to better understand and manage long-term complications.

Antibody persistence of standard versus double three-dose hepatitis B vaccine in liver transplant children: a randomized controlled trial

Rapid hepatitis B (HB) surface antibody (anti-HBs) loss is prevalent after liver transplantation (LT). Herein, we evaluated anti-HBs persistence after HB vaccination using two regimens in LT children. We recruited 66 previously immunized LT children with anti-HBs level of < 100 mIU/mL. Participants were randomly reimmunized with standard-three-dose (SD) and double-three-dose (DD) intramuscular HB vaccination at 0, 1, and 6 months. Anti-HBs were assessed at every outpatient visit. Antibody loss defined as anti-HBs levels < 100 mIU/mL after three-dose vaccination. After three-dose vaccination, 81.8% and 78.7% of participants in the SD and DD groups, had anti-HBs levels > 100 mIU/mL, with a geometric mean titer (GMT) of 601.68 and 668.01 mIU/mL (P = 0.983). After a mean follow-up of 2.31 years, the anti-HBs GMT was 209.81 and 212.61 mIU/mL in the SD and DD groups (P = 0.969). The number of immunosuppressants used and an anti-HBs level < 1 mIU/mL at baseline were independently associated with anti-HB loss. The DD regimen strongly increased the risk of anti-HBs loss (adjusted hazard ratio, 2.97 [1.21-7.31]; P = 0.018). The SD HB reimmunization regimen effectively maintained protective anti-HBs levels in children undergoing LT, making it the preferred regimen for such children with anti-HB loss.Trial registration: TCTR20180723002.

Approach to vaccinating the pediatric solid organ transplant candidate and recipient

Solid organ transplantation (SOT) candidates and recipients are at increased risk for morbidity and mortality from vaccine-preventable infections. Children are at particular risk given that they may not have completed their primary immunization series at time of transplant or have acquired natural immunity to pathogens from community exposures. Multiple society guidelines exist for vaccination of SOT candidate and recipients, although challenges remain given limited safety and efficacy data available for pediatric SOT recipients, particularly for live-vaccines. After transplant, individual patient nuances regarding exposure risks and net state of immunosuppression will impact timing of immunizations. The purpose of this review is to provide readers with a concise, practical, expert-opinion on the approach to vaccinating the SOT candidate and recipient and to supplement existing guidelines. In addition, pediatric-specific knowledge gaps in the field and future research priorities will be highlighted.

Eliminating viral hepatitis in children after liver transplants: How to reach the goal by 2030

Viral hepatitis infections are a great burden in children who have received liver transplant. Hepatotropic viruses can cause liver inflammation that can develop into liver graft fibrosis and cirrhosis over the long term. Immunological reactions due to viral hepatitis infections are associated with or can mimic graft rejection, rendering the condition difficult to manage. Prevention strategies using vaccinations are agreeable to patients, safe, cost-effective and practical. Hence, strategies to eliminate viral hepatitis A and B focus mainly on immunization programmes for children who have received a liver transplant. Although a vaccine has been developed to prevent hepatitis C and E viruses, its use is not licensed worldwide. Consequently, eliminating hepatitis C and E viruses mainly involves early detection in children with suspected cases and effective treatment with antiviral therapy. Good hygiene and sanitation are also important to prevent hepatitis A and E infections. Donor blood products and liver grafts should be screened for hepatitis B, C and E in children who are undergoing liver transplantation. Future research on early detection of viral hepatitis infections should include molecular techniques for detecting hepatitis B and E. Moreover, novel antiviral drugs for eradicating viral hepatitis that are highly effective and safe are needed for children who have undergone liver transplantation.

Safety and Immunogenicity of Standard and Double Doses of Hepatitis B Vaccine in Children after Liver Transplantation: An Open-Label, Randomised Controlled Trial

A high prevalence of hepatitis B (HepB) antibody loss after liver transplantation (LT) and de novo HepB infection (DNH) was documented, hence revaccination to prevent DNH is crucial. This study aimed to compare the safety and immunogenicity of two HepB vaccine regimens in liver-transplanted children. Liver-transplanted children who were previously immunised but showed HepB surface antibodies (anti-HBs) ≤ 100 mIU/mL were randomised to receive a standard three-dose (SD) and double three-dose (DD) vaccine intramuscularly in months 0–1–6. Anti-HBs and T-cell-specific response to the HepB antigen were assessed. A total of 61 children (54.1% male, aged 1.32 ± 1.02 years) completed the study without any serious adverse reaction. The seroprotective rate was 69.6% vs. 60% (p = 0.368) and 91.3% vs. 85% (p = 0.431) in SD and DD after the first and third 3-dose vaccinations, respectively. The geometric mean titre (95% confidence interval) of anti-HBs in SD and DD were 443.33 (200.75–979.07) vs. 446.17 (155.58–1279.50) mIU/mL, respectively, at completion. Numbers of interferon-γ-secreting cells were higher in hyporesponders/responders than in nonresponders (p = 0.003). The significant factors for the immunologic response to HepB vaccination were anti-HB levels prevaccination, tacrolimus trough levels, and time from LT to revaccination. SD and DD had comparative immunogenicity and were safe for liver-transplanted children who were previously immunised.

De novo HBV Hepatitis in a Child with Liver Transplantation

Background: Omental torsion (OT) presents as a rare, infrequent pathology with often non-specific symptoms. This condition occurs when the greater omentum is twisted around its axis, producing perfusion defects and vascular impairment of the organ. This case report describes an overweight 26-year-old Caucasian man presenting with acute abdomen in previous appendectomy, whose definitive surgical diagnosis was omental torsion. Omental torsion is a rare pathology regarding the causes of acute abdomen associated with a challenging diagnosis. Case report: We report about a female toddler with liver transplantation due to extrahepatic biliary atresia, who was detected to have positive HBsAg, 27 months after transplantation. Before liver transplantation, routine serologic assessments were negative for HBV infection, the child was vaccinated with three doses of HBV vaccine and developed seroprotective Abs titers. Organ donor was the father, who was negative for HBV infection had negative anti-HBc and had seroprotective titers of anti HBs. A PCR assay in our patient revealed the presence of serum HBV DNA with an increased viral load. The patient started antiviral treatment with Entecavir and had serological response within three months, showing elimination of serum HBV DNA and HBsAg values. Serological investigation of all family members and information from the transplantation unit did not reveal the infection source. Conclusion:de novo Hepatitis B in liver recipients is a rare phenomenon. In donor positive anti-HBc cases, it appears as reactivation of HBV infection. There are very few published cases in which recipients developed de novo HBV hepatitis, despite seronegative HBcAb donors. Caregivers should always be alert for de novo hepatitis B in liver transplanted children as loss of immunity could be an unexpected phenomenon, despite pre-transplant negative serology of the donor and recipient as so as despite seroprotective Abs titers after immunisation of the recipient.

The effect of universal infant vaccination on the prevalence of hepatitis B immunity in adult solid organ transplant candidates

BACKGROUND

Hepatitis B virus (HBV) immunity is recommended to optimize outcomes after solid organ transplantation (SOT). This study assessed the prevalence and predictors of HBV immunity at the time patients were placed on transplant waiting list over a period from 1997 to 2019 in a low HBV endemic region.

METHODS

Data were obtained from the University Hospitals Leuven transplant database. Minors and patients with past/current HBV infection were excluded. From 1986, Belgian patients are covered by the universal infant vaccination; therefore, birth cohort was stratified in those born ≥1986 vs <1986.

RESULTS

The study population consisted of 3297 SOT candidates. HBV immunity rate was superior in renal transplant candidates (55.3%), and this number was 21.5%, 15.4% and 16.8% for liver, cardiac and pulmonary transplant candidates, respectively, P < .001. Among liver transplant candidates, HBV immunity rate was 14.8% in decompensated cirrhotic patients and 27.9% in those without advanced cirrhosis (P < .001). The overall immunity rate increased from 19.3% in period 1997-2008 to 32.8% in 2009-2019, P < .001. In multivariable analyses, younger age (odds ratio (OR) 95% confidence interval (CI): 0.97-0.98, P < .001) and birth cohort ≥ 1986 (OR 95% CI: 1.18-2.66, P = .006) were associated with increased HBV immunity.

CONCLUSION

An increase in HBV immunity was observed over a 20-year period related to the introduction of universal infant HBV vaccination. Nevertheless, this study highlights the low overall HBV immunity at the time of listing for organ transplantation and points out the need of an increased awareness and vaccination strategy at an early disease stage.

Prophylactic Strategy Against De Novo Hepatitis B Virus Infection for Pediatric Recipients Who Receive Hepatitis B Core Antibody-Positive Liver Grafts

The goal of this study was to evaluate the efficacy of a perioperative prophylactic strategy against de novo hepatitis B virus (HBV) infection in pediatric liver transplantation (LT) recipients with hepatitis B core antibody (HBcAb)-positive grafts. A total of 482 pediatric recipients transplanted between 2013 and 2017 were enrolled, and 170 recipients received HBcAb-positive liver grafts. The overall graft and recipient survival rates in HBcAb-positive and HBcAb-negative graft recipients were 91.8% versus 91.3% and 95.3% versus 94.2% at the end of follow-up. Preoperative hepatitis B surface antibody (HBsAb) titer ≥ 1000 IU/L and postoperative HBsAb titer ≥200 IU/L were our prophylactic targets for recipients receiving HBcAb-positive grafts. While 11 recipients developed de novo HBV infection, 10 received HBcAb-positive grafts. Both the preoperative and postoperative HBsAb targets were achieved in 78 recipients, the infection rate of de novo HBV was 1.3%; 24 recipients met the preoperative target, the infection rate was 4.2%; 52 recipients met the postoperative target, the infection rate was 1.9%; and 16 recipients met neither the preoperative nor postoperative HBsAb target, 43.8% of the recipients were infected with de novo HBV, which was significantly higher than the recipients who met both or either of the preoperative and postoperative targets. Split-liver grafts positive for HBcAb showed higher risk of de novo HBV infection. Postoperative application of lamivudine to recipients whose preoperative HBsAb titer < 1000 IU/L did not show preventive effect. Out of 11 infected recipients, 3 showed seroconversion under entecavir treatment. In conclusion, the graft and recipient survival rates were similar in pediatric LT recipients receiving HBcAb-positive or HBcAb-negative grafts. Our prophylactic strategy was effective for preventing de novo HBV infection in HBcAb-positive liver graft recipients.

New blood-borne virus infections among organ transplant recipients: An Australian data-linked cohort study examining donor transmissions and other HIV, hepatitis C and hepatitis B notifications, 2000-2015

BACKGROUND

Blood-borne viral infections can complicate organ transplantation. Systematic monitoring to distinguish donor-transmitted infections from other new infections post transplant is challenging. Administrative health data can be informative. We aimed to quantify post-transplant viral infections, specifically those transmitted by donors and those reactivating or arising new in recipients.

METHODS

We linked transplant registries with administrative health data for all solid organ donor-recipient pairs in New South Wales, Australia, 2000-2015. All new recipient notifications of hepatitis B (HBV), C (HCV), or human immunodeficiency virus (HIV) after transplant were identified. Proven/probable donor transmissions within 12 months of transplant were classified using an international algorithm.

RESULTS

Of 2120 organ donors, there were 72 with a viral infection (9/72 active, 63/72 past). These 72 donors donated to 173 recipients, of whom 24/173 already had the same infection as their donor, and 149/173 did not, so were at risk of donor transmission. Among those at risk, 3/149 recipients had proven/probable viral transmissions (1 HCV, 2 HBV); none were unrecognized by donation services. There were no deaths from transmissions. There were no donor transmissions from donors without known blood-borne viruses. An additional 68 recipients had new virus notifications, of whom 2/68 died, due to HBV infection.

CONCLUSION

This work confirms the safety of organ donation in an Australian cohort, with no unrecognized viral transmissions and most donors with viral infections not transmitting the virus. This may support targeted increases in donation from donors with viral infections. However, other new virus notifications post transplant were substantial and are preventable. Data linkage can enhance current biovigilance systems.

Management of Hepatitis B Virus Infection and Prevention of Hepatitis B Virus Reactivation in Children With Acquired Immunodeficiencies or Undergoing Immune Suppressive, Cytotoxic, or Biological Modifier Therapies

Reactivation of hepatitis B virus (HBV) is a known complication of immune-suppressive, cytotoxic, and biological modifier therapies in patients currently infected with HBV or who have had past exposure to HBV. Nowadays, newer and emerging forms of targeted biologic therapies are available for the management of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions and solid-organ, bone marrow, or haematologic stem cell transplant but there is currently a lack of a systematic approach to the care of patients with or at risk of HBV reactivation. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) together with a working group of ESPGHAN members with clinical and research expertise in viral hepatitis developed an evidence-based position paper on reactivation of HBV infection in children identifying pertinent issues addressing the diagnosis, prevention, and treatment of this condition. Relevant clinical questions were formulated and agreed upon by all the members of the working group. Questions were answered and positions were based on evidence resulting from a systematic literature search on PubMed and Embase from their inception to July 1, 2019. A document was produced and the working group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique. A recommendation was accepted provided upon agreement by at least 75% of the working group members. This position paper provides a comprehensive update on the diagnosis, prevention and treatment of HBV reactivation in children.

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

INASL Guidelines on Management of Hepatitis B Virus Infection in Patients receiving Chemotherapy, Biologicals, Immunosupressants, or Corticosteroids

Hepatitis B Virus (HBV) reactivation in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids is emerging to be an important cause of morbidity and mortality in patients with current or prior exposure to HBV infection. These patients suffer a dual onslaught of illness: one from the primary disease for which they are receiving the culprit drug that led to HBV reactivation, and the other from HBV reactivation itself. The HBV reactivation not only leads to a compromised liver function, which may culminate into hepatic failure; it also adversely impacts the treatment outcome of the primary illness. Hence, identification of patients at risk of reactivation before starting these drugs, and starting treatment aimed at prevention of HBV reactivation is the best strategy of managing these patients. There are no Indian guidelines on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids for the treatment of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions, or solid-organ or bone marrow transplantation. The Indian National Association for Study of the Liver (INASL) had set up a taskforce on HBV in 2016, with a mandate to develop consensus guidelines for management of various aspects of HBV infection, relevant to India. In 2017 the taskforce had published the first INASL guidelines on management of HBV infection in India. In the present guidelines, which are in continuation with the previous guidelines, the issues on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids are addressed.

The use of hepatitis B immunoglobulin with or without hepatitis B vaccine to prevent de novo hepatitis B in pediatric recipients of anti-HBc-positive livers

Prophylactic measures are used to reduce DNHB after HBsAg-negative patients receive anti-HBc-positive liver grafts. This study investigated the incidence of DNHB and clinical outcomes in pediatric LT recipients under HBIG prophylaxis, with or without hepatitis B vaccination. Between 1995 and 2013, 51 HBsAg-negative pediatric recipients underwent living-donor LT from anti-HBc-positive donors. The median (range) age was 4 (0.1-17) years, 23 (45%) were male, and 71% were negative for both anti-HBc and anti-HBc. During a median follow-up of 12.1 (0.06-19.9) years, 13 (25.4%) developed DNHB; 7 of the 13 achieved HBsAg seroconversion after administration of LAM or ETV. Among studied patients, 20 (39%) received hepatitis B vaccination, and 2 of them (10%) developed DNHB. At last follow-up, 41% (21/51) discontinued HBIG either after successful HBV vaccination (n = 17) or retransplantation with anti-HBc-negative grafts (n = 4). In conclusion, pediatric LT recipients of anti-HBc-positive grafts, most of them were naïve to HBV infection, were at high risk of DNHB, and consistent monitoring for the early detection of DNHB was necessary. A combination use of post-LT vaccination is promising prophylactic strategy against DNHB.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation (LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally, despite the decrease in the prevalence of hepatitis B virus (HBV) over the past two decades, the absolute number of HBsAg-positive people has increased, leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently, a large demand exists for LT. While the wait time for patients on the donor list is, to some degree, shorter due to the development of living donor liver transplantation (LDLT), there is still a shortage of liver grafts. Furthermore, recipients often suffer from emergent conditions, such as liver dysfunction or even hepatic encephalopathy, which can lead to a limited choice in grafts. To expand the pool of available liver grafts, one option is the use of organs that were previously considered “unusable” by many, which are often labeled “marginal” organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however, there is still a lack of discussion on this topic, especially regarding the feasibility of using marginal grafts in LDLT. Therefore, the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.

High prevalence of hepatitis B-antibody loss and a case report of de novo hepatitis B virus infection in a child after living-donor liver transplantation

AIM

To assess the seroprevalence of hepatitis B virus (HBV) immunity among previously vaccinated pediatric liver transplant recipients and present a case report of de novo hepatitis B infection after liver transplantation.

METHODS

This study focused on children with chronic liver diseases who received primary hepatitis B immunization and had a complete dataset of anti-HBs before and after liver transplantation between May 2001 and June 2017. Medical records were retrospectively reviewed for potential factors relating to HBV immunity loss.

RESULTS

In total, 50 children were recruited. The mean time from liver transplantation to anti-HBs testing was 2.53 ± 2.11 years. The mean anti-HBs levels before and after liver transplantation were 584.41 ± 415.45 and 58.56 ± 6.40 IU/L, respectively. The rate of non-immunity (anti-HBs < 10 IU/L) in the participants was 46% (n = 26) at one year, 57% (n = 7) at two years and 82% (n = 17) at > three years following liver transplantation. The potential factors relating to HBV immunity loss after liver transplantation were identified as anti-HBs (P = 0.002), serum albumin (P = 0.04), total bilirubin (P = 0.001) and direct bilirubin (P = 0.003) before liver transplantation. A five-year-old boy with biliary cirrhosis received 4 doses of HBV vaccine with an anti-HBs titer of > 1000 IU/L and underwent liver transplantation; his anti-HBc-negative father was the donor. After liver transplantation, the boy had stenosis of the hepatic artery up to the inferior vena cava anastomosis and underwent venoplasty three times. He also received subcutaneous injections of enoxaparin for 5 mo and 20 transfusions of blood components. Three years and ten months after the liver transplantation, transaminitis was detected with positive tests for HBsAg, HBeAg, and anti-HBc (2169.61, 1706 and 8.45, respectively; cutoff value: < 1.00) and an HBV viral load of 33212320 IU/mL.

CONCLUSION

The present study showed that loss of hepatitis B immunity after liver transplantation is unexpectedly common. In our case report, despite high levels of anti-HBs prior to transplantation, infection occurred at a time when, unfortunately, the child had lost immunity to hepatitis B after liver transplantation.

Active immunization for prevention of De novo hepatitis B virus infection after adult living donor liver transplantation with a hepatitis B core antigen-positive graft

De novo hepatitis B virus (DNHB) infections may occur in recipients who do not receive prophylaxis after liver transplantation (LT) with antibody to hepatitis B core antigen (anti-HBc)-positive donor grafts. Active immunization has been shown to prevent DNHB in pediatric recipients. Our aim is to investigate the efficacy of HBV vaccination for preventing DNHB in adult living donor liver transplantation (LDLT). In total, 71 adult antibody to hepatitis B surface antigen (anti-HBs)-negative LDLT patients who received anti-HBc+ grafts from 2000 to 2010 were enrolled into this study. Patients were given hepatitis B virus vaccinations with the aim of achieving anti-HBs > 1000 IU/L before transplant and >100 IU/L after transplant. The cohort was stratified into 3 groups: patients with pretransplant anti-HBs titer of > 1000 IU/L without the need for posttransplant prophylaxis (group 1, n = 24), patients with pretransplant low titer of <1000 IU/L who were given posttransplant lamivudine prophylaxis and responded appropriately to posttransplant vaccination by maintaining anti-HBs titers of > 100 IU/L (group 2, n = 30), and low titer nonresponders (anti-HBs titer of < 100 IU/L despite vaccination), for whom lamivudine was continued indefinitely (group 3, n = 17). All DNHB occurred in group 3 patients with posttransplant anti-HBs levels of < 100 IU/L, with an incidence rate of 17.6% compared with 0% in patients with posttransplant anti-HBs levels of > 100 IU/L (P = 0.001). A pretransplant anti-HBs level of >1000 IU/L was significantly associated with early attainment and a sustained level of posttransplant anti-HBs of >100 IU/L (P < 0.001). Active immunization is effective in preventing DNHB in adult LDLT if the posttransplant anti-HBs level is maintained above 100 IU/L with vaccination. Antiviral prophylaxis can be safely discontinued in patients who obtain this immunity. Liver Transplantation 23 1266-1272 2017 AASLD.

Risks and treatment strategies for de novo hepatitis B virus infection from anti-HBc-positive donors in pediatric living donor liver transplantation

The aim of this study was to analyze the incidence and risk factors of de novo HBV infection in pediatric patients receiving living donor liver transplants (LDLT) from HBcAb-positive donors, and to explore its treatment strategies. The data of 101 pediatric recipients receiving LDLT in Tianjin First Central Hospital between September 2006 and December 2012 were retrospectively analyzed. The HBV markers were regularly tested before and after the surgery, including HBsAb, HBsAg, HBeAg, HBeAb, and HBcAb. The median follow-up period was 25.6 months, during which eight cases (7.92%) were diagnosed with de novo HBV infection. Forty-four (43.6%) of the children received HBcAb-positive allografts. The rate of de novo HBV in the children that received HBcAb+ livers vs those received HBcAb- livers was 15.9% (7/44) vs 1.7% (1/57) (P=.037). The rates of de novo HBV in the children who received HBcAb-positive allografts were significantly less than in those that received preventative therapy with HBIG and lamivudine treatment (2/31, 6.4%) vs those that did not (5/13, 38.5%) (P<.01). HBcAb-positive liver donors are strongly associated with de novo HBV in HBsAg-negative pediatric patients receiving LDLT. However, the incidence of de novo HBV infection is significantly less with the use of prophylactic treatment strategies.

Long-term efficacy of hepatitis B vaccination as post-transplant prophylaxis in hepatitis B surface antigen (HBsAg) positive recipients and HBsAg negative recipients of anti-hepatitis B core positive grafts

AIM

Hepatitis B virus (HBV) reactivation after liver transplantation in HBV patients, or in HBV negative recipients of anti-hepatitis B core (HBc) positive grafts, has been prevented by prophylactic use of hepatitis B immunoglobulin (HBIG) and/or nucleoside/nucleotide analogs (NA). Vaccination against HBV is an alternative that may provide a chance to discontinue prophylaxis by producing anti-hepatitis B surface (HBs) antibodies.

METHODS

We retrospectively reviewed 40 HBV positive recipients (HBV+ group) and 27 HBV negative recipients of anti-HBc positive grafts (HBV-/anti-HBc+ graft group), who were administrated double-dose hepatitis B vaccination. Recipients were regarded as responders when anti-HBs greater than 100 IU/L was maintained for 6 months or more without HBIG. Response rates of vaccine and long-term outcomes were analyzed.

RESULTS

Eighteen of the 40 patients in the HBV+ group (45%) and 18 of the 27 patients in the HBV-/anti-HBc+ graft group (67%) responded to vaccination after a median of four and three times, respectively. Younger age was the only independent factor associated with vaccine response in the HBV-/anti-HBc+ graft group (P = 0.03), whereas no factor was found to be an independent predictor for vaccine response in the HBV+ group. Among the 18 responders in the HBV+ group, 17 remained without NA or HBIG 8.2 years after the start of vaccination. Ten of those required periodic booster vaccination. All 18 responders in the HBV-/anti-HBc+ graft group remained free from HBV prophylaxis 6.2 years after the start of vaccination.

CONCLUSION

Younger recipients have a greater chance to develop sufficient anti-HBs after double-dose HBV vaccination, leading to discontinue HBV prophylaxis.

De novo hepatitis b prophylaxis with hepatitis B virus vaccine and hepatitis B immunoglobulin in pediatric recipients of core antibody-positive livers

The use of hepatitis B core antibody-positive (HBcAb+) grafts for liver transplantation (LT) has the potential to safely expand the donor pool, as long as proper prophylaxis against de novo hepatitis B (DNHB) is employed. The aim of this study was to characterize the longterm outcome of pediatric LT recipients of HBcAb + liver grafts under a prophylaxis regimen against DNHB using hepatitis B virus (HBV) vaccine and hepatitis B immunoglobulin (HBIG). From June 1996 to February 2013, 49 patients receiving pediatric LT at our center were from HBcAb + donors. Forty-one patients who received DNHB prophylaxis according to our protocol were included in this analysis. Our DNHB prophylaxis protocol consists of HBV vaccine intramuscular injections given intermittently to maintain anti-hepatitis B surface antibody (HBsAb) titers above 100 IU/L. HBIG was also used during the first posttransplant year with a target anti-HBsAb titer level above 200 IU/L. There were 19 boys and 22 girls. Median age was 1.0 year (range, 4 months to 16 years). Median follow-up time was 66 months after transplant. Median annual number of HBV vaccine injections was 0.8 per year (range, 0-1.8 per year). Four patients did not require any HBV vaccine injections during follow-up. One patient with DNHB was encountered during the follow-up period (1/41, 2.4%). DNHB was diagnosed at 3.5 years after transplant, when hepatitis B surface antigen was positive upon routine follow-up serologic testing. Anti-HBsAb titer was 101.5 IU/L at the time. No grafts were lost because of DNHB-related events. Overall survival of the 41 recipients of HBcAb + grafts who received DNHB prophylaxis was 92.3% at 10 years after transplant. In conclusion, longterm prophylaxis against DNHB with HBV vaccine in pediatric LT recipients of HBcAb + grafts was safe and effective in terms of DNHB incidence as well as graft and patient survival.

Molecular Mechanisms to Control Post-Transplantation Hepatitis B Recurrence

Hepatitis B often progresses to decompensated liver cirrhosis requiring orthotopic liver transplantation (OLT). Although newer nucleos(t)ide analogues result in >90% viral and hepatitis activity control, severely decompensated patients still need OLT because of drug-resistant virus, acute exacerbation, or hepatocellular carcinoma. Acute hepatitis B is also an indication for OLT, because it can progress to fatal acute liver failure. After OLT, the hepatitis B recurrence rate is >80% without prevention, while >90% of transplant recipients are clinically controlled with combined hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogue treatment. However, long-term HBIG administration is associated with several unresolved issues, including limited availability and extremely high cost; therefore, several treatment protocols with low-dose HBIG, combined with nucleos(t)ide analogues, have been investigated. Another approach is to induce self-producing anti-hepatitis B virus (HBV) antibodies using an HBV envelope (HBs) antigen vaccine. Patients who are not HBV carriers, such as those with acutely infected liver failure, are good candidates for vaccination. For chronic HBV carrier liver cirrhosis patients, a successful vaccine response can only be achieved in selected patients, such as those treated with experimentally reduced immunosuppression protocols. The present protocol for post-OLT HBV control and the future prospects of newer treatment strategies are reviewed.

De novo hepatitis B virus infection after pediatric liver transplantations with hepatitis B core antibody-positive donors: a single-center 20-yr experience

DNHB is common in countries with high prevalence of hepatitis B, and therefore, contracting hepatitis B after LT with HBcAb(+) grafts is a major concern. We studied DNHB in 247 children (aged <18 yr) who underwent LT from 1994 to 2013. Sixty-six of 247 recipients received HBcAb(+) donor grafts. The incidence of DNHB was 5.7% (14 of 247 children) and that in HBcAb(+) donor grafts was 19.7% (13 of 66 children). The incidence of DNHB without LAM prophylaxis was 31.3% (nine of 29 children), while that with prophylaxis was 10.8% (four of 37 children). LAM prophylaxis negatively correlated with DNHB by Cox regression analysis (p = 0.028, odds ratio = 0.258). Among 13 DNHB patients with HBcAb(+) donor grafts, eight recovered from DNHB and four showed the emergence of LAM resistance. There was no DNHB-related graft failure. This study showed that HBcAb(+) donor graft was associated with development of DNHB, and use of LAM prophylaxis decreased the incidence of DNHB with HBcAb(+) graft.

Solid organ transplantation from hepatitis B virus-positive donors: consensus guidelines for recipient management

Use of organs from donors testing positive for hepatitis B virus (HBV) may safely expand the donor pool. The American Society of Transplantation convened a multidisciplinary expert panel that reviewed the existing literature and developed consensus recommendations for recipient management following the use of organs from HBV positive donors. Transmission risk is highest with liver donors and significantly lower with non-liver (kidney and thoracic) donors. Antiviral prophylaxis significantly reduces the rate of transmission to liver recipients from isolated HBV core antibody positive (anti-HBc+) donors. Organs from anti-HBc+ donors should be considered for all adult transplant candidates after an individualized assessment of the risks and benefits and appropriate patient consent. Indefinite antiviral prophylaxis is recommended in liver recipients with no immunity or vaccine immunity but not in liver recipients with natural immunity. Antiviral prophylaxis may be considered for up to 1 year in susceptible non-liver recipients but is not recommended in immune non-liver recipients. Although no longer the treatment of choice in patients with chronic HBV, lamivudine remains the most cost-effective choice for prophylaxis in this setting. Hepatitis B immunoglobulin is not recommended.

Successful active immunization using a hepatitis B virus vaccination protocol for a recipient with hepatitis B core antibody-positive liver graft

INTRODUCTION

Donor shortages occasionally necessitate the use of hepatic allografts from hepatitis B core antibody-positive (HBcAb+) donors, with an attendant risk of post-transplantation hepatitis B virus (HBV) infection. The aim of the present study was to develop and evaluate a protocol of active immunization for prevention of post-transplantation de novo HBV infection in patients receiving liver grafts from HBcAb+ donors.

PATIENTS AND METHODS

Ten patients who had received HBcAb+ liver grafts at Shinshu University Hospital between October 1996 and December 2012 were enrolled. All the recipients were negative for HBV serological tests, and HBV-DNA. Hepatitis B immunoglobulin (HBIG) was given routinely in the peritransplantation and post-transplantation periods, without antiviral drugs. Subcutaneous vaccination with recombinant HBV was given at a dosage of 20 μg in adults and 5 μg in children concomitant with HBIG until acquisition of active immunization. The timing to start HBV vaccination was dependent on the condition of the patient.

RESULTS

The median follow-up period after liver transplantation was 140 months, and the median period after transplantation until the start of vaccination was 7.0 months. Nine patients (90%) acquired active immunity after a median number of 4 (range, 2-13) vaccinations (hepatitis B surface antibody >300 mIU/mL for 1 year, or >100 mIU/mL thereafter), and did not require HBIG administration thereafter. None had any side effects of HBV vaccination or developed hepatitis B infection during the study period. Four fast responders who achieved antibody high titers by active immunization within 9 months received pretransplantation vaccinations, whereas 5 slow responders did not.

CONCLUSIONS

Our vaccination protocol provides a new effective strategy for prevention of de novo hepatitis B infection after liver transplantation in recipients with HBcAb+ liver grafts. Pretransplantation HBV vaccination was helpful for the post-transplantation vaccine response.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Contradictory immune response in post liver transplantation hepatitis B and C

Hepatitis B and C often progress to decompensated liver cirrhosis requiring orthotopic liver transplantation (OLT). After OLT, hepatitis B recurrence is clinically controlled with a combination of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues. Another approach is to induce self-producing anti-hepatitis B virus (HBV) antibodies using a HBV envelope antigen vaccine. Patients who had not been HBV carriers such as acutely infected liver failure or who received liver from HBV self-limited donor are good candidate. For chronic HBV carrier patients, a successful response can only be achieved in selected patients such as those treated with experimentally reduced immunosuppression protocols or received an anti-HBV adaptive memory carrying donor liver. Hepatitis C virus (HCV) reinfects transplanted livers at a rate of >90%. HCV reinfected patients show different severities of hepatitis, from mild and slowly progressing to severe and rapidly progressing, possibly resulting from different adaptive immune responses. More than half the patients require interferon treatment, although the success rate is low and carries risks for leukocytopenia and rejection. Managing the immune response has an important role in controlling recurrent hepatitis C. This study aimed to review the adaptive immune response in post-OLT hepatitis B and C.

Section 14. Combination of entecavir plus low-dose on-demand hepatitis B immunoglobulin is effective with very low hepatitis B recurrence after liver transplantation

BACKGROUND AND AIMS

Antiviral prophylaxis with hepatitis B immunoglobulin (HBIg) plus lamivudine reduces the risk of hepatitis B virus (HBV) recurrence after HBV-related liver transplant (LT). However, HBIg is expensive, and lamivudine therapy is limited by drug resistance. This study assessed a pilot study of entecavir plus low-dose, on-demand HBIg in preventing HBV recurrence after LT.

METHODS

Between 2006 and May 2011, approximately 145 patients undergoing HBV-related LT and receiving entecavir plus low-dose, on-demand HBIg were enrolled and followed for a median of 36 months. A historical control group of 171 patients undergoing HBV-related LT between 1998 and 2010 and receiving lamivudine plus HBIg were followed for a median of 77 months. The primary end point was the proportion of patients with recurrent HBsAg-positivity.

RESULTS

In the entecavir cohort, 2 (1.37%) of 145 patients experienced HBV recurrence, none of which had evidence of viral resistance. In the lamivudine cohort, 11 (6.4%) of 171 cases of HBV recurrence were observed, 5 of which were associated with lamivudine resistance. The cumulative probabilities of HBV recurrence were significantly different between both cohorts (P=0.055). HBsAg recurrence was associated with lower overall survival (P<0.001), even in patients with undetectable HBV DNA. Using pooled data from both cohorts, predictors of HBV recurrence were nucleoside selection, pre-LT hepatocellular carcinoma, post-LT low anti-HBs, male sex, and HBsAg-positivity in the explant liver tissue.

CONCLUSIONS

Entecavir plus low-dose, on-demand HBIg resulted in a low rate of HBV recurrence without evidence of resistance development and provided an effective and cost-saving strategy for patients having HBV-related LT.

2013 IDSA clinical practice guideline for vaccination of the immunocompromised host

An international panel of experts prepared an evidenced-based guideline for vaccination of immunocompromised adults and children. These guidelines are intended for use by primary care and subspecialty providers who care for immunocompromised patients. Evidence was often limited. Areas that warrant future investigation are highlighted.

Why does living donor liver transplantation flourish in Asia?

The success of liver transplantation worldwide has brought increased demand for the liver graft. Western and Asian countries have coped differently with the problems of the shortages in organ donation. In the West, efforts have focused on promoting deceased donor organ donation, whereas in Asia the focus has been on living donor liver transplantation (LDLT), as this procedure is more acceptable in most Asian cultures. LDLT, which was initially devised for paediatric liver transplant patients, has evolved from using a left lobe graft to a right lobe graft for an adult recipient. To widen the donor pool, dual grafts for a single recipient have been used in LDLT, and donors with hepatitis B core antibody positivity have been accepted, as well as ABO incompatible donors and recipients. The great advances in the field of LDLT have been dictated by the needs and the norms of Asian society. In this Perspectives article, we outline the reasons why LDLT flourishes in Asia.

Matching donor to recipient in liver transplantation: Relevance in clinical practice

Achieving optimum outcomes after liver transplantation requires an understanding of the interaction between donor, graft and recipient factors. Within the cohort of patients waiting for a transplant, better matching of the donor organ to the recipient will improve transplant outcomes and benefit the overall waiting list by minimizing graft failure and need for re-transplantation. A PubMed search was conducted to identify published literature investigating the effects of donor factors such as age, gender, ethnicity, viral serology; graft factors such as size and quality, recipient factors such as age, size, gender and transplant factors such as major or minor blood group incompatibility and immunological factors. We also report technical and therapeutic modifications that can be used to manage donor-recipient mismatch identified from literature and the authors’ clinical experience. Multiple donor and recipient factors impact graft survival after liver transplantation. Appropriate matching based on donor-organ-recipient variables, modification of surgical technique and innovative peri-transplant strategies can increase the donor pool by utilizing grafts from marginal donors that are traditionally turned down.

Serologic vaccination response after solid organ transplantation: a systematic review

BACKGROUND

Infectious diseases after solid organ transplantation (SOT) are one of the major complications in transplantation medicine. Vaccination-based prevention is desirable, but data on the response to active vaccination after SOT are conflicting.

METHODS

In this systematic review, we identify the serologic response rate of SOT recipients to post-transplantation vaccination against tetanus, diphtheria, polio, hepatitis A and B, influenza, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitides, tick-borne encephalitis, rabies, varicella, mumps, measles, and rubella.

RESULTS

Of the 2478 papers initially identified, 72 were included in the final review. The most important findings are that (1) most clinical trials conducted and published over more than 30 years have all been small and highly heterogeneous regarding trial design, patient cohorts selected, patient inclusion criteria, dosing and vaccination schemes, follow up periods and outcomes assessed, (2) the individual vaccines investigated have been studied predominately only in one group of SOT recipients, i.e. tetanus, diphtheria and polio in RTX recipients, hepatitis A exclusively in adult LTX recipients and mumps, measles and rubella in paediatric LTX recipients, (3) SOT recipients mount an immune response which is for most vaccines lower than in healthy controls. The degree to which this response is impaired varies with the type of vaccine, age and organ transplanted and (4) for some vaccines antibodies decline rapidly.

CONCLUSION

Vaccine-based prevention of infectious diseases is far from satisfactory in SOT recipients. Despite the large number of vaccination studies preformed over the past decades, knowledge on vaccination response is still limited. Even though the protection, which can be achieved in SOT recipients through vaccination, appears encouraging on the basis of available data, current vaccination guidelines and recommendations for post-SOT recipients remain poorly supported by evidence. There is an urgent need to conduct appropriately powered vaccination trials in well-defined SOT recipient cohorts.

Efficacy of combined antiviral therapy with lamivudine and tenofovir in a liver transplanted girl with de novo hepatitis B virus infection

The management of de novo hepatitis B (HBV) infection in children after liver transplantation is not well defined. Because this infection may induce severe liver disease in the graft liver, an efficient antiviral therapy is desirable. Here, we describe the favorable viral outcome observed in a liver transplanted girl with de novo HBV infection following combination therapy with lamivudine and tenofovir.

Emerging hepatitis B virus infection in vaccinated populations: a rising concern?

Hepatitis B infection, especially by perinatal transmission, is endemic in Asian countries. After the first successful universal hepatitis B virus (HBV) vaccination programme for newborns in Taiwan, it became feasible to prevent HBV transmission and the resultant hepatocellular carcinoma in endemic countries. However, a small subset of vaccinated people have a suboptimal immunological response to vaccination, and the immunity of some young adults who were vaccinated as infants seems to have waned over time. Despite this loss, recent studies suggest that anamnestic anti-HBs antibody responses rapidly resume and eliminate acute HBV infection acquired through sexual contact or blood transfusion, even though the anti-HBs antibody titre has decreased below a protective level. These observations indicate prolonged protection by the HBV vaccine. Therefore, for people with a low infection risk, a universal booster vaccination is not currently recommended, but it should be considered for high-risk groups. However, we still advocate close monitoring of acute hepatitis B among patients who lack a protective level of anti-HBs antibody and suggest a wait-and-see policy to determine the necessity for booster vaccines.

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.

Different effect of HBV vaccine after liver transplantation between chronic HBV carriers and non-HBV patients who received HBcAb-positive grafts

BACKGROUND

Combination of nucleos(t)ide analogue and anti-HBs immunoglobulin (HBIg) is the standard protocol for prevention of HBV reactivation after liver transplantation, but because of the extremely high cost of HBIg, HBV vaccine is tried as a much cheaper and potentially safer substitute. Here we show the different effect of HBV vaccine between chronic HBV carrier and non-HBV patients who received grafts from HBc antibody-positive donors.

METHODS

Fifteen chronic HBV carriers and 6 non-HBV patients who received grafts from HBc antibody-positive donors were included in this study. These patients received double dose of pre-S-containing HBV vaccine every month from later than 12 months after liver transplantation. Successful vaccination was defined as HBsAb >100 IU/l without HBIg administration for 3 months.

RESULTS

None of the 15 chronic HBV carriers succeeded in maintaining high enough HBsAb titers. In contrast, 5 of 6 non-HBV patients with HBcAb-positive donors achieved HBsAb >100 IU/l without HBIg coadministration. Recipient HBV status (HBV carrier/non-HBV) was considered to have a stronger effect on vaccine success (p < 0.001) though recipient age (p = 0.006) was also selected as a significant factor.

CONCLUSIONS

Recipient HBV status seems to be the most important factor affecting success of HBV vaccine after liver transplantation. In non-HBV patients who received grafts from HBcAb-positive donors, HBV vaccination is an effective, cost-saving, and safe method for prevention of HBV reactivations. In contrast in chronic HBV patients, response rate was quite poor, so some modifications such as combination with adjuvant or modification of administration schedules should be considered.

Liver transplantation for primary biliary cirrhosis in a hepatitis endemic region: a single-center Asian experience

From March 1984 to November 2008, we performed 539 primary liver transplantations (LTs). Nineteen (19, 3.5%) were transplanted for end-stage liver disease secondary to primary biliary cirrhosis (PBC). There were 17 (89%) female and 2 (11%) male recipients. The overall mean age was 50.3 ± 6.3 yr. The mean model for end-stage liver disease, and Child-Turcotte-Pugh scores were 20.7 ± 2.1, and 11.0 ± 0.5, respectively. There were 2 (11%) United Network for Organ Sharing status 3, 16 (84%) 2B, and 1 (5%) 2A patients. Fourteen patients (14, 73.7%) underwent living donor LT, and five patients (26.3%) received deceased donor LT. The primary immunosuppression consisted of cyclosporine (n = 5) and tacrolimus (n = 14). Liver function returned to normal one month after transplantation. The overall mean follow-up was 5.8 ± 0.8 yr (range, four months to 15.7 yr). The overall one-, three-, and five-yr survival rates were 94.7%, 89.2%, and 89.2%, respectively. Without hepatitis B virus (HBV) prophylaxis, one patient acquired de novo HBV infection after receiving a graft from an anti-HBc(+) donor. Another patient developed recurrent hepatitis C infection and expired 25 months after transplantation. Our results showed that HBV prophylaxis was effective not only against de novo infection, but it also worked on pre-transplant HBV carrier with PBC and helped in virus clearance.

Liver grafts from anti-hepatitis B core positive donors: a systematic review

BACKGROUND & AIMS

Although hepatitis B virus (HBV) transmission after liver transplantation of grafts from HBsAg-negative, anti-HBc positive donors is well established, the growing organ shortage favours the use of such marginal grafts. We systematically evaluated the risk of HBV infection after liver transplantation with such grafts and the effect of anti-HBV prophylaxis.

METHODS

We performed a literature review over the last 15 years identifying 39 studies including 903 recipients of anti-HBc positive liver grafts.

RESULTS

Recurrent HBV infection developed in 11% of HBsAg-positive liver transplant recipients of anti-HBc positive grafts, while survival was similar (67-100%) to HBsAg-positive recipients of anti-HBc negative grafts. De novo HBV infection developed in 19% of HBsAg-negative recipients being less frequent in anti-HBc/anti-HBs positive than HBV naive cases without prophylaxis (15% vs 48%, p<0.001). Anti-HBV prophylaxis reduced de novo infection rates in both anti-HBc/anti-HBs positive (3%) and HBV naive recipients (12%). De novo infection rates were 19%, 2.6% and 2.8% in HBsAg-negative recipients under hepatitis B immunoglobulin, lamivudine and their combination, respectively.

CONCLUSIONS

Liver grafts from anti-HBc positive donors can be safely used, preferentially in HBsAg-positive or anti-HBc/anti-HBs positive recipients. HBsAg-negative recipients should receive prophylaxis with lamivudine, while both anti-HBc and anti-HBs positive recipients may need no prophylaxis at all.

Clinical course of de novo hepatitis B infection after pediatric liver transplantation

The characteristics of hepatitis B virus (HBV) in vaccinated children who acquire de novo HBV infections after orthotopic liver transplantation (OLT) remain largely unknown. The aim of this study was to explore HBV mutants in pediatric OLT recipients with de novo HBV infections. In all, 50 recipients underwent OLT between December 1997 and October 2005, and they were regularly checked for HBV serum markers from November 2005 to April 2009. Before OLT, all were hepatitis B surface antigen (HBsAg)-negative and under the coverage of the universal infant HBV vaccination program. Those who became HBsAg-positive after OLT were diagnosed with de novo HBV infection. HBV viral loads and full-length genome sequencing were determined when the diagnosis of de novo HBV infection was established. Nine patients (9/50, 18%) acquired de novo HBV infections after OLT. None had graft loss or fulminant hepatitis. Five cleared HBsAg, and 4 of the 5 even recovered with antibody to hepatitis B surface antigen (anti-HBs) formation. The other 4 were persistently HBsAg-positive. Mutations in the major S gene (681 base pairs) were discovered in 8 (88.9%) of the de novo HBV-infected children. Six of them harbored mutations within the "a" determinant region (codons 124-147), whereas the other 2 had mutations outside this region. These 2 cleared HBsAg and recovered with anti-HBs formation. HBV DNA levels were not different between those who cleared HBsAg and those who did not. In conclusion, surface mutants are frequent among pediatric liver transplant recipients with de novo HBV infections, but their clinical relevance requires further study.

Hepatitis B vaccination in children: the Taiwan experience

The world's first nationwide hepatitis B virus (HBV) universal vaccination program for infants was launched in Taiwan in July, 1984. All infants received three to four doses plasma or recombinant HBV vaccines. In addition, infants of HBeAg-positive mothers received 0.5ml of hepatitis B immunoglobulin within 24hours after birth. The vaccination coverage rate is as high as 97%. Seroprevalence of hepatitis B surface antigen (HBsAg) declined from 9.8% (prevaccination period) to 0.6% in children in Taipei City after 20years of mass vaccination. The seropositive rates for HBsAg, antibody to HBsAg, and antibody to hepatitis B core antigen were 1.2%, 50.5%, and 3.7%, respectively, in those born after the vaccination program (<20years old) in 2004. In line with the decrease of chronic HBV infection, the incidence of hepatocellular carcinoma (HCC) also decreased in children in Taiwan. From 1981 to 1994, the incidence of HCC in 6- to 9-year-olds declined from 0.52/100,000 for those born between 1974 and 1984 to 0.13 for those born between 1984 and 1986 (p<0.001). We extended the observation to 2000, the incidence of HCC per 100,000 children declined from 0.54 to 0.20. The prevalence of a determinant mutants (amino acids 121-149 of HBsAg) in Taiwanese carrier children was 7.8% (eight out of 103) in 1984, increased to 19.6% (10 out of 51) in 1989, peaked at 28.1% (nince out of 32) in 1994, and remained stationary at 23.1% (three out of 13) and about 25% in 1999 and 2004, respectively; it was higher in those fully vaccinated compared with those not vaccinated. The other group of subjects who are susceptible to vaccine failure is the immunocompromized hosts. We observed some de novo HBV infection in children after liver transplantation. Despite of the success of hepatitis B immunization, childhood chronic HBV infection and HCC were not eliminated by the universal vaccination program. Among those HBsAg carriers born after the vaccination program, 89% of their mothers were found to be positive for HBsAg, indicating the importance of maternal transmission. This was also true in the mothers of children with HCC, of them 96% were HBsAg positive. After two decades of universal infant HBV vaccination, we found this program provides long-term protection for up to more than 20years, and a universal booster is not required for the primary HBV vaccinees before adulthood. Mother-to-child transmission, although largely diminished, is still the main cause for immunoprophylaxis failure. The emergence of escape mutant did not impose increased risk of chronic infection at present. Nevertheless, development of new vaccines may overcome the vaccine failure.

Toward elimination and eradication of hepatitis B

Hepatitis B virus (HBV) causes important human health problems. It has infected one-third of the world's population and approximately 360 million people are chronic carriers. Worldwide, 0.5-1.2 million deaths are attributed to HBV infection annually. Therefore, global control of HBV infection is important. HBV infection can be intervened by interrupting routes of transmission, treating the chronically infected, and preventing the susceptibles with immunoprophylaxis. All these measures are effective. Nevertheless, although pegylated interferons or nucleos(t)ide analogs are effective for the treatment of chronic hepatitis B, chronic carriage of HBV is not easy to eliminate, as revealed by the frequent persistence of hepatitis B surface antigen, despite satisfactory responses to these treatments. On the other hand, hepatitis B vaccination has been shown to preclude HBV infection effectively. This is particularly true for pre-exposure prophylaxis. Worthy of note is the universal vaccination of newborn infants. This is the most effective means of preventing HBV infection, especially for those born to HBV carrier mothers. To eliminate and eradicate hepatitis B, first, HBV in the chronically infected should be eradicated or strongly and efficiently suppressed, so that the infection does not spread rampantly. Second, all the transmission routes should be interrupted. Lastly, but most effectively, is to immunize all susceptibles. The difficulties and possible solutions of each approach are discussed. In conclusion, the existing means to prevent and treat HBV infection render our goal toward eliminating and eradicating hepatitis B possible, although it will take much time and effort to achieve this objective.

Hepatitis B vaccination: The key towards elimination and eradication of hepatitis B

Hepatitis B virus infection is a global health problem. Worldwide, about 360 million people are chronically infected with the virus. They continue to spread the virus to others and are themselves at risk of chronic liver diseases and hepatocellular carcinoma. The infection can now be treated by antivirals or interferons and the transmission route can be interrupted. Nevertheless, the most effective means is to immunize all susceptible individuals, especially young children, with safe and efficacious vaccines. The combined efforts of vaccination, effective treatment and interruption of transmission make elimination of the infection plausible and may eventually lead to eradication of the virus. Because hepatitis B vaccination has a key role in the control of hepatitis B, properties of this vaccine, its effectiveness in pre-exposure and post-exposure settings, duration of protection after vaccination and the need of booster doses are discussed. Mass hepatitis B vaccination in children decreases the carriage of the virus, and the diseases associated with acute and chronic infection, including hepatocellular carcinoma. Challenges that need to be solved to expand mass vaccination, and the strategies towards elimination and eventual eradication of hepatitis B in the world are also discussed.

High-titer antibody to hepatitis B surface antigen before liver transplantation can prevent de novo hepatitis B infection

OBJECTIVE

De novo hepatitis B virus (HBV) infection is defined as infection occurring in HBV surface antigen (HBsAg)-negative patients who become HbsAg positive after organ transplantation. We assessed the incidence and risk factors of de novo HBV infection in pediatric liver transplant recipients.

PATIENTS AND METHODS

From 1996 to 2006, 71 Taiwanese children with non-HBV-related liver diseases underwent orthotopic liver transplantation (OLT) at the National Taiwan University Hospital. All of the surviving recipients were tested regularly for liver function, serum levels of immunosuppressant, HBsAg, titers of antibodies to hepatitis B surface antigen (anti-HBs), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C virus (anti-HCV). HBV vaccination histories and the anti-HBs titers before OLT were recorded. No regular prophylaxis was given.

RESULTS

Fifty-nine patients (33 girls and 26 boys) were followed up for a median of 4.4 years (range 1.0-10.0). Of those, 36 (61.0%) received allografts from anti-HBc-positive and HBsAg-negative donors. De novo HBV infection was found in 9 (15.3%) patients after OLT, 8 of whom received allografts from HBsAg-negative and anti-HBc-positive donors. Forty-eight (81.4%) patients received 3 or more doses of HBV vaccine before OLT. Pre-OLT anti-HBs titers were available for 49 recipients. Of the 9 de novo HBV-infected recipients, 8 had anti-HBs titers <200 mIU/mL. No graft loss or fulminant hepatitis was noted.

CONCLUSIONS

In the absence of adequate prophylaxis, the incidence of de novo HBV infection in pediatric OLT recipients is 15.3%. An anti-HBs titer of >200 mIU/mL before OLT may be sufficient to prevent de novo HBV infection in HBsAg-negative recipients.

Response to booster hepatitis B vaccines in liver-transplanted children primarily vaccinated in infancy

BACKGROUND

A hepatitis B virus (HBV) universal vaccination program for infants was implemented for 24 years in Taiwan. Most of the children who received organ transplantation were primarily vaccinated before transplantation. This study investigated the efficacy of HBV vaccination and booster responses in children after liver transplantation (LT).

METHODS

Totally 31 children were enrolled. They were clinically stable for more than 1 year after LT. Twenty of them kept a titer of antibody to hepatitis B surface antigen (anti-HBs) more than 10 mIU/mL and received no booster, while 11 received one booster because their anti-HBs titers were less than 10 mIU/mL. Cellular immunity was checked by enzyme-linked immunospot assay with interferon-gamma surrogated for T-helper 1 cells and interleukin-5 for T-helper 2 before and after booster vaccine.

RESULTS

One of the non-boosters had de novo HBV infection after LT and recovered to be anti-HBs positive. The first booster restored an adequate titer in 64% (7/11) of those with anti-HBs titer less than 10 mIU/mL after LT. The four patients who failed the first booster responded well to the second dose. After the booster, the mononuclear cells of all 11 had more than one spot-forming cell for interferon-gamma or interleukin-5. Transplanted girls maintained a higher antibody titer than boys.

CONCLUSION

Primary HBV vaccination or the booster dose(s) of HBV vaccine could provide adequate humoral and cellular immunity in children with LT.

Double-dose double-phase use of second generation hepatitis B virus vaccine in patients after living donor liver transplantation: Not an effective measure in transplant recipients

AIMS

Post-transplant active immunization for chronic hepatitis B patients has been attempted in several studies with controversial results. We assessed the effect of a double-dose double-phase vaccination regimen among partial living donor liver recipients.

METHODS

Eighteen patients who underwent liver transplantation (LT) for chronic hepatitis B and two non-hepatitis B virus (HBV)-infected patients who received hepatitis B core antibody (HBcAb)-positive donor organs were recruited 18-78 months after LT. All were on hepatitis B immunoglobulin (HBIG) mono-prophylaxis before and throughout vaccination, to maintain hepatitis B surface antibody (HBsAb) titers of more than 100 IU/mL. Recombinant hepatitis B surface antigen vaccine (40 microg) was administered intramuscularly during weeks 0, 4, 8, 24, 28 and 32.

RESULTS

The patients consisted of 15 males and five females with a median age of 52 (39-59) years. None developed a sufficient HBsAb titer above 500 IU/mL by week 48. In two patients whose maximum HBsAb titer increased to above 300 IU/mL, we attempted to skip HBIG, but shortly thereafter the titer dropped below 100 IU/mL and HBIG administration was resumed. Although the HBIG dose was reduced during and after vaccination, cessation of administration was not achieved.

CONCLUSION

Double-dose double-phase use of second generation recombinant vaccine was not effective in this study population. The selected population should be targeted for a conventional vaccine regimen, and different approaches, such as strong adjuvant or pre-S containing protein, should be further tested in a larger number of patients after LT for chronic hepatitis B.

Inadequate humoral immunogenicity to recombinant hepatitis B virus vaccine in biliary atresia children

This study aimed to investigate the primary immunogenicity and the long-term efficacy of recombinant hepatitis B virus (HBV) vaccine in biliary atresia (BA) children. Fifty BA infants (age, 11 +/- 3.9 mo), and 23 BA patients at childhood (age, 8.5 +/- 0.22 y) were included for the evaluation of HBV surface antibody (anti-HBs) levels after three doses of recombinant HBV vaccine immunization. Age- and gender-matched healthy infants (n = 50) and children (n = 23) were enrolled as the control group. Serum samples of the study populations were collected for HBV seromarkers determination. In the absence of hepatitis B virus core antibody and HBV surface antigen, serum anti-HBs level above 10 IU/L was considered adequate immunogenicity to HBV vaccine. The prevalence of adequate anti-HBs levels after recombinant HBV vaccine in BA infants was significantly lower than those of the controls (p = 0.006). There was no difference in the prevalence between childhood BA patients and their matched controls (p = 0.538). In conclusion, adequate primary humoral immunity after the standard doses of recombinant HBV vaccine in BA infants is hard to establish. However, once immunity is acquired, BA children have adequate anti-HBs titer in the long run.

Hepatitis B virus vaccine switch program for prevention of de novo hepatitis B virus infection in pediatric patients

The principal objective of this study was to evaluate the feasibility of Hepatitis B virus (HBV) vaccine switch program after 1-year Hepatitis B immunoglobulin (HBIG) for the prevention of de novo HBV (DNHBV) infection in pediatric recipients of hepatitis B core antibody (anti-HBc)-positive grafts. In this study, we enrolled pediatric recipients (n = 14), who had undergone living donor liver transplantation with anti-HBc-positive grafts between July 2000 and July 2005 and were followed up for over 24 months after transplantation. HBIG was given daily during the first week and intermittently in order to maintain anti-hepatitis B surface antigen (anti-HBs) titers greater than 200 IU/l until 12 months post-transplantation. Then the HBV vaccine was given intermittently as a substitute for HBIG when anti-HBs titer fell below 200 IU/l. The median follow-up duration after vaccination was 26.5 months, and a median of 2.03 doses of vaccine per year was required for the maintenance of anti-HBs titers greater than at least 100 IU/l. Two of the patients did not start the HBV vaccine due to sustained high anti-HBs titer. Eleven completed the HBV switch, whereas 1 was ongoing. With the HBV vaccine switch program, anti-HBs titers greater than 100 IU/l could be maintained conveniently and effectively.