Major Finding: Among children being treated with infliximab for IBD, 51% had no immunity to hepatitis B and were at increased risk for liver complications.
Data Source: A prospective, single-center study of 100 children with IBD.
Disclosures: Dr. Moses had no financial conflicts to disclose.
SAN ANTONIO — Approximately half of children being treated with infliximab for inflammatory bowel disease did not have immunity to hepatitis B, based on data from 100 children.
Patients with inflammatory bowel disease (IBD) treated with infliximab who lack immunity to hepatitis B virus are at risk for severe liver disease if exposed to the virus in the community, noted Dr. Jonathan Moses of the Cleveland Clinic.
To determine the degree of hepatitis B virus (HBV) immunity, Dr. Moses and his colleagues conducted a prospective study of 100 consecutive children who were being treated with infliximab for IBD at a single center; 91 of the children (91%) had Crohn's disease. The mean duration of infliximab therapy was 38 months, and the mean dose was 7 mg/kg.
Blood samples were taken at a routine visit for infliximab infusion. The samples were tested for three markers: hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs). Patients with anti-HBs levels of 10 mIU/mL or higher were considered immune.
Regardless of vaccination history, 49% of the children were immune to HBV and 51% were not. The mean concentration of anti-HBs levels in the immune children was 295.6 mIU/mL.
The children were aged 5-18 years (mean, 13 years) at the time of diagnosis with IBD. The mean age at which the blood sample for this study was taken was 18 years. Approximately 60% of the patients were boys, and most were white.
Vaccination data were available for 87 patients, 91% of whom had been vaccinated. Most of these patients received the hepatitis B vaccine as part of their routine childhood immunization schedules, so they had a 5- to 10-year gap between the time they received hepatitis B vaccination and the time they started infliximab for IBD, Dr. Moses said.
Factors related to HBV immunity, including body mass index percentile and Crohn's disease location, were similar between the two groups. Patients with immunity were slightly older at the time of IBD diagnosis.
A booster dose of HBV vaccine had been given to 20 patients, and the full vaccination series had been started in 7 patients at the time of the study presentation at the meeting.