Evaluation of memory immunity and serum antibody level measurement of hepatitis B virus surface antigen in children with autism compared to control group

Regarding the reported abnormalities in the immune system of people with autism, it is likely that these people do not respond appropriately to the hepatitis B vaccine or do not become immune to the hepatitis B virus following the injection of hepatitis B vaccine. There is no information available on the quality and response of the hepatitis B vaccine in children with autism. The purpose of this study was to investigate the effect of primary hepatitis B vaccine in children with autism in preventing of hepatitis B 3-15 years after primary vaccination and investigate the of HBs-Ab waning along with age and the existence of an immune memory against hepatitis B vaccine in these children compared with the healthy control child as contrl.

Total 254 HBsAg-negative objective with ages between 3-15years. from ASD and normal population were recruited, HBV seromarkers (HBc-Ab & HBs-Ag & HBs-Ab) were assessed and subsequently, molecular tests were employed on all subjects for detection of hepatitis B virus DNA in the serum samples and positive cases were investigated for mutations in the HBs-Ag coding region. A booster dose of vaccine was injected for those who showed low levels (<10 mIU/mL) of anti-HBs and their antibody levels was measured 4 weeks afterwards.

The mean ages for ASD and control groups were 7.14±2.42 and 8.68±1.96 respectively. In ASD group 7 (6.5%) of children were positive for anti-HBc and one child was positive for occult hepatitis B infection (HBsAg negative, HBV DNA positive). From the normal control group, nobody was found to be positive for this parameter. There was no mutation in the HBS-Ag coding region. In ASD and Control groups 49.6% had low anti-HBs levels (HBs-Ab < 10 mIU/mL), One month After injection of a booster dose for all children with low antibody, 100% of ASD and 92% (59 of 64) of control pupils contained >10 mIU/mL of antibody, respectively. In both groups, the HBs-Ab titer increased similarly in response to the booster injection (P<0.05).

According results, vaccine-induced immunity should be checked until puberty and thereafter. Despite previous investigations regarding immune impairment in individuals with autism, the immune system of these individuals was able to manage the hepatitis B vaccine challenge.