Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02985450 |
Other study ID # |
REB16-0274 |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
August 2016 |
Est. completion date |
January 2021 |
Study information
Verified date |
June 2018 |
Source |
University of Calgary |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
(1) Due to missed childhood vaccination programs, the majority of adult patients with NAFLD
in Canada do not have immunity to hepatitis B. (2) Adults with NAFLD who receive the HBV
vaccine have reduced immunogenic responses in the setting of obesity (i.e., protective
anti-HBs titres). Aims: (1) To determine the sero-prevalence of immunity against hepatitis B
in a cohort of prospectively evaluated adult NAFLD patients. (2) To prospectively determine
HBV vaccine responses (anti-HBs titres) in adult NAFLD patients.
Description:
The hepatitis B virus (HBV) is truly a global human pathogen that affects at least 2 billion
people worldwide including ~240 million chronic hepatitis B (CHB) carriers that are at risk
for end-stage liver disease. The diagnosis of CHB is confirmed by the persistence of the HBV
surface antigen (HBsAg) in serum for >6 months. However, a latent form of HBV infection known
as occult hepatitis B infection (OBI) characterized by low-level viremia (i.e., HBV DNA < 200
IU/ml) despite undetectable serum HBsAg has been described with unclear clinical
consequences.
A safe and effective HBV vaccine has been available for ~3 decades and consists of
recombinant HBsAg which contains the major viral antigenic epitopes and induces a protective
neutralizing antibody to HBsAg (anti-HBs) response in >85% of children vaccinated. Canada is
a low HBV-endemic region and in Alberta, and Ontario, public health uses maternal screening
for HBsAg to identify babies at-risk for CHB. Thus, all infants born to HBsAg (+) mothers are
given passive-active immunoprophylaxis with hepatitis B immune globulin (HBIG) and the HBV
vaccine within 12 hours of birth, as well as 2 doses at ~2 and ~6 months of age. Testing of
the infants for anti-HBs is recommended at 9 months to ensure immunity. In the late 1990's, a
universal HBV childhood vaccination program was initiated in all Canadian provinces and
jurisdictions. In Alberta and in Ontario, school-age children are scheduled to receive the
3-dose HBV vaccine series in grade 5. However there remain a significant proportion of adult
Canadians (i.e., born before 1985) who missed childhood vaccination programs. Although
current guidelines recommend that certain high-risk populations receive hepatitis B
immunization, appropriate identification and compliance is generally much lower in adults
compared to children.
According to the most recent Canadian Association for the Study of Liver Disease guidelines,
all adults with diabetes, as well as all patients with chronic liver disease should receive
the hepatitis B vaccine. The basis for these recommendations are two-fold, (1) diabetics may
be at risk of blood-borne virus (BBV) exposure through contact with contaminated blood
glucose monitoring devices and (2) diabetic patients are at increased risk of the metabolic
syndrome and the development of non-alcoholic fatty liver disease (NAFLD). The improvement in
blood glucose monitoring devices, and increased knowledge has reduced the risk of HBV
exposure in patients with diabetes. Further, the investigators' initial seroepidemiological
survey of acute HBV outbreaks in Alberta revealed a decreasing prevalence in diabetic
patients. Therefore the main incentive for HBV vaccination in diabetics is due to the
concomitant risk of the metabolic syndrome and advanced liver disease due to NAFLD. There is
limited data on HBV vaccination in NAFLD patients. Further studies are required in a North
American adult (Canadian population).
The investigators propose that adults with NAFLD should undergo comprehensive screening for
hepatitis B immunogenicity, in addition to screening for infection, and catch up or booster
vaccinations should be administered to non-immunized patients with confirmatory immunity
testing thereafter.