Effectiveness of the Hepatitis B Vaccine Post-Hematopoietic Stem Cell Transplant
Condition: Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis
Study type: Observational

Summary: 
      Background:

      Stem cell transplants (SCTs) are important in treating many diseases. There are two main
      types of transplants. Autologous stem cells come from the person getting the cells.
      Allogeneic stem cells come from another person. The risk of hepatitis B virus (HBV) is high
      after allogeneic SCT. Even if a person receives the HBV vaccine after transplant, he or she
      may not really be immune to HBV. The person may become immune only after repeated series of
      the vaccine. Researchers need to learn more about the HBV vaccine in people after transplant
      so it can be most effective.

      Objective:

      To assess the rate of achieved HBV immunity for people who had an SCT who did not become
      immune with the first vaccine series and require 2 or more series.

      Eligibility:

      People who have had at least 1 dose of the HBV vaccine and were enrolled in these protocols:
      99-H-0050, 10-H-0154, and 08-H-0046

      Design:

      Participants will be screened in the other protocols.

      Participants data and medical charts will be reviewed.

      Data from up to 350 participants who had transplants before March 2016 will be reviewed.

      Participants data will be collected:

      Demographic data

      Type of transplant

      Type of donor

      Clinical information about the transplant...
    

Detailed description: 
      Based on current medical literature, the risk of hepatitis B reactivation is high after
      allogenic stem cell transplant and can be a major problem in the post-transplant population,
      leading to increased morbidity and mortality. Additionally, many people in the general
      population and transplant population do not achieve immunity against hepatitis B with the
      first vaccination series and may require repeat series.

      Currently, it is unclear as to what percentage of post-transplant patients have a failed or
      delayed immunity against hepatitis B and how many vaccine series it may take to eventually
      achieve immunity. Previous data has eluded toward a seroconversion rate of 64% in children
      and adults after vaccination with 20% of patients losing immunity by 5-years
      post-vaccination. Additionally, the study found that 25% of patients did not achieve
      protective titers following one vaccination series and of those that went on to be
      revaccinated, 55% achieved seroconversion.

      This is a single-center, retrospective analysis examining the effectiveness of the hepatitis
      B vaccine posthematopoietic stem cell transplant and the impact of factors that may affect
      seroconversion. Through this study, we hope to collect data on hepatitis B vaccination and
      recommend potential protocol revisions if trends are found. We hypothesize that hepatitis B
      immunity post-first vaccine series will occur in the majority of patients evaluated and that
      patients failing to respond to the first vaccine series, will respond to subsequent
      vaccination series.

      The primary objective will be to assess the rate of achieved immunity for those patients that
      do not achieve immunity with the first vaccine series and require two or more vaccine series.
      Secondary and exploratory objectives will include the evaluation of the percentages of
      patients responding to vaccination on the 1st, 2nd, and 3rd attempt at the hepatitis B
      vaccination series, the rate of reactivation of hepatitis B, and the analysis of factors
      potentially impacting the response to vaccination.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patient who have received at least one dose of the hepatitis B vaccine
      
Keywords: Hepatitis B Reactivation; Allogenic Stem Cell Transplant; Natural History