Incidence of Low Seroimmunity to Hepatitis B Virus in Children With Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) often receive immunosuppressive therapy, which may make them vulnerable to infections such as hepatitis B. We hypothesized that hepatitis B virus titers are low in the vaccinated pediatric population with IBD. The aims of our study were to identify the incidence of lower titers of hepatitis B surface antibody (HBsAb) and determine which patient factors may be associated with lower HBsAb titers.

Patients with diagnosis of IBD, ages 5 to 18 years, were prospectively enrolled. Patients were confirmed to have had a full series of hepatitis B vaccination. Quantitative serum HBsAb titers were measured and logistic regression analysis with independent variables of age, sex, race, disease phenotype, surgery, medications and a dependent variable of adequate HBsAb titers (> 10 mIU/mL) was performed.

Of the 116 patients enrolled, 57 were boys and 59 were girls. 75 patients had a diagnosis of Crohn disease; 32 had a diagnosis of ulcerative colitis; and 9 patients had been diagnosed as having indeterminate colitis. At the time of the study, 15 patients were taking corticosteroid, 66 on an immunomodulator, and 53 on a biologic. Sixty percent of patients in the 5- to 10-year age group had protective titers versus 22% to 27% in the older groups, P = 0.04. Only 28% of the 116 patients had HBsAb titers of >10m IU/mL. Twenty percent of the patients taking corticosteroids, 27% taking immunomodulators, and 24% taking biologics were found to be seroimmune.

Nearly two-thirds of pediatric patients with IBD have low titers against hepatitis B virus. Titers were highest in the younger patients. No patient-specific variable, such as the use of immunosuppressants, appeared to influence these low titers.