Immune status and the immune response to hepatitis B virus vaccine in thalassemic patients after allogeneic bone marrow transplantation

Immunizations in solid organ and hematopoeitic stem cell transplant patients: A comprehensive review

The Solid Organ Transplantation (SOT) and Haematopoietic Stem Cell Transplantation (HSCT) population is continuously increasing as a result of broader indications for transplant and improved survival. Infectious diseases, including vaccine-preventable diseases, are a significant threat for this population, primarily after but also prior to transplantation. As a consequence, clinicians must ensure that patients are optimally immunized before transplantation, to provide the best protection during the early post-transplantation period, when immunosuppression is the strongest and vaccine responses are poor. After 3-6 months, inactivated vaccines immunization can be resumed. By contrast, live-attenuated vaccines are lifelong contraindicated in SOT patients, but can be considered in HSCT patients at least 2 years after transplantation, if there is no immunosuppression or graft-versus-host-disease. However, because of the advantages of live-attenuated over inactivated vaccines--and also sometimes the absence of an inactivated alternative--an increasing number of prospective studies on live vaccine immunization after transplantation are performed and give new insights about safety and immunogenicity in this population.

Infectious diseases in allogeneic haematopoietic stem cell transplantation: prevention and prophylaxis strategy guidelines 2016

Infectious complications after allogeneic haematopoietic stem cell transplantation (allo-HCT) remain a clinical challenge. This is a guideline provided by the AGIHO (Infectious Diseases Working Group) of the DGHO (German Society for Hematology and Medical Oncology). A core group of experts prepared a preliminary guideline, which was discussed, reviewed, and approved by the entire working group. The guideline provides clinical recommendations for the preventive management including prophylactic treatment of viral, bacterial, parasitic, and fungal diseases. The guideline focuses on antimicrobial agents but includes recommendations on the use of vaccinations. This is the updated version of the AGHIO guideline in the field of allogeneic haematopoietic stem cell transplantation utilizing methods according to evidence-based medicine criteria.

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.

Early vaccination with tumor-lysate-pulsed dendritic cells after allogeneic bone marrow transplantation has antitumor effects

Allogeneic bone marrow transplantation (BMT) remains the primary treatment for many hematologic malignancies but has had limited success against solid tumors. The antitumor activity of this treatment approach involves the tumoricidal activity of chemoradiation and the additive graft-versus-tumor activity of donor T cells. However, even with current protocols, some tumors develop resistance and become unresponsive to current therapeutic regimens. To address the problem of resistance and lack of solid tumor activity in allogeneic BMT, we undertook experiments to determine whether the graft-versus-tumor activity of donor T cells could be enhanced in the period immediately after allogeneic BMT with tumor lysate-pulsed dendritic cell (DC) vaccines. Using the B16 melanoma model, we found that the treatment of 6-day tumors with allogeneic BMT and 3 weekly vaccinations of tumor lysate-pulsed DCs starting 3 days after BMT had a significant effect on the growth of murine flank melanomas. This effect was tumor specific and occurred in the absence of full immune reconstitution as measured by donor T cell engraftment and cytotoxic T lymphocyte activity. In addition, DC vaccinations did not appear to exacerbate graft-versus-host disease. These experiments support the feasibility of DC vaccine strategies in the setting of allogeneic BMT.

Immunogenicity of recombinant hepatitis B vaccine (rHBV) in recipients of unrelated or related allogeneic hematopoietic cell (HC) transplants

Current European and US guidelines for recombinant hepatitis B vaccine (rHBV) after hematopoietic-cell transplantation (HCT) vary. The European Group for Blood and Marrow Transplantation (EBMT) recommends rHBV starting 6 to 12 months after HCT. Immunization is optional in the Centers for Disease Control and Prevention (CDC) guidelines. Nevertheless, rHBV is required for re-entry to school and certain workplaces. To determine the immunogenicity of rHBV following HCT, the prevaccine and postvaccine titers of 292 allogeneic transplant recipients who were immunized with rHBV were analyzed. Immunization was initiated in patients off immunosuppression who achieved specific minimal milestones of immune competence. Overall, 64% of patients seroconverted. In multivariate analyses, response was adversely affected by age older than 18 years (P < .01) and history of prior chronic graft-versus-host disease (GVHD; P < .001) but not by donor type or by use of T-cell depletion, adoptive immunotherapy, or rituximab. By comparison, 89% of rHBV nonresponders mounted a 3-fold or greater rise in polio titers following 3 doses of inactivated poliovirus. These data demonstrate that the rate of seroconversion following rHBV is lower in allogeneic HC transplant recipients compared with age-matched healthy controls. The data emphasize the need to document prevaccine and postvaccine titers to ensure response and suggest that immunization guidelines based on time interval from HCT, irrespective of immune competence, may not ensure adequate protection against certain vaccine-preventable diseases.

Recombinant hepatitis B vaccine (Engerix-B): a review of its immunogenicity and protective efficacy against hepatitis B

Engerix-B (Hep-B[Eng]) is a noninfectious recombinant DNA vaccine containing hepatitis B surface antigen (HBsAg). It is produced from genetically engineered yeast (Saccharomyces cerevisiae). Intramuscular Hep-B(Eng) [0-, 1-, 6-month schedule] has excellent immunogenicity in healthy neonates and infants, children, adolescents and adults, with seroprotection rates of 85-100% seen approximate, equals 1 month after the final dose of vaccine; seroprotection was defined as an antibody against HBsAg (anti-HBs) titre of > or =10 IU/L. The use of alternative Hep-B(Eng) immunisation schedules (e.g. a 0-, 1-, 2-, 12-month schedule in neonates and infants, 0-, 12-, 24-month or two-dose schedules in children and adolescents, and accelerated schedules in adults) have also been associated with high rates of seroprotection. Seroprotection rates were generally similar with Hep-B(Eng) and the recombinant vaccine Recombivax HB (Hep-B[Rax]) or plasma-derived vaccines (PDVs) approximate, equals 1 month after the final dose (although anti-HBs geometric mean titres were significantly higher with Hep-B[Eng] than with Hep-B[Rax]). One month after the final dose, adults had significantly higher seroprotection rates with the recombinant triple-antigen vaccine Bio-Hep-B (Hep-B[Bio]) than with Hep-B(Eng), although seroprotection rates in healthy infants were similar with Hep-B(Eng) and Hep-B(Bio). Hep-B(Eng) had excellent immunogenicity in several groups considered at high risk of acquiring hepatitis B (e.g. neonates born to hepatitis B carrier mothers and healthcare workers). The immunogenicity of Hep-B(Eng) was reduced in patients with conditions associated with impaired immune function (e.g. patients undergoing haemodialysis or being treated for malignancy), although it had good immunogenicity in patients with diabetes mellitus.Hep-B(Eng) had excellent protective efficacy against HBsAg carriage in healthy infants and children, and in neonates born to hepatitis B carrier mothers (protective efficacy of 95-99%). Hep-B(Eng) also demonstrated good protective efficacy in a number of other high-risk groups. Hep-B(Eng) is generally well tolerated with a tolerability profile similar to that of Hep-B(Rax), Hep-B(Bio) and PDVs. In conclusion, Hep-B(Eng) is a well established, highly immunogenic hepatitis B vaccine with good tolerability and excellent protective efficacy; it offers flexibility through a variety of immunisation schedules. In addition, it appears that Hep-B(Eng) confers immunity for at least 10 years. Hep-B(Eng) has an important role in mass vaccination campaigns against hepatitis B, as well as in groups considered at high risk of acquiring hepatitis B.

Double-dose accelerated hepatitis B vaccine in patients with end-stage liver disease

The aims of this study are to assess the efficacy of hepatitis B virus (HBV) vaccination using an accelerated schedule and double dose of recombinant vaccine in liver transplant recipients and identify factors associated with seroconversion and persistence of antibody to hepatitis B surface antigen (anti-HBs). Three hundred fifty-six patients were enrolled. Exclusion criteria were previous HBV infection, fulminant liver failure, or less than 2 years of follow-up after orthotopic liver transplantation (OLT). The vaccination schedule was 0, 2 weeks, 4 weeks, and 6 months using double-dose recombinant vaccine. Seroconversion was evaluated prospectively by measuring anti-HBs on the day of OLT and 1 and 2 years after OLT. Quantitative analyses of anti-HBs were performed retrospectively on stored sera. Geometric mean concentrations (GMCs) were calculated using a standard formula. All patients completed the full vaccination schedule, and 129 patients (36%) completed the schedule before OLT. The overall prevalence of anti-HBs was 128 of 356 pre-OLT samples (36%) compared with 41 of 353 (11.6%) and 26 of 325 post-OLT samples (8%) 1 and 2 years after OLT, respectively (both P =.001). The pre-OLT GMC was 86.7 compared with 0.32 and 0.33 at 1 and 2 years after OLT, respectively (P =.001). Patients with high titers of anti-HBs before OLT were more likely to have persistence of antibodies 1 or 2 years after OLT. Younger age (P =.02), low Child-Pugh score (P =.02), underlying chronic hepatitis C (P=.03), and specific host HLA subtypes were most strongly associated with seroconversion and/or persistence of anti-HBs. Thus, (1) seroconversion before or after OLT using double-dose accelerated-schedule vaccination against HBV is low, (2) there is a rapid, significant decrease in antibody titer after OLT, (3) pre-OLT anti-HBs titer potentially may be useful in predicting persistence of protective antibodies after OLT, and (4) several factors (age, genetic predisposition, severity of liver disease, and underlying liver disease) may have a role in poor vaccine responsiveness.