Patients with inflammatory bowel disease who have been vaccinated for hepatitis B virus (HBV) are more likely to have low levels of protective hepatitis B surface antibodies (HBsAbs) after exposure to infliximab (IFX), according to retrospective study findings published in Inflammatory Bowel Diseases.
Investigators retrospectively reviewed medical charts of adult patients with Crohn’s disease or ulcerative colitis who had recently been vaccinated for HBV and/or who had ≥1 positive HBsAb test. Patients were included for analysis if they had received inflammatory bowel disease therapy in the 6-month period before HBsAb titer assessment. Researchers stratified patients according to exposure to antitumor necrosis factor (TNF), immunomodulator, or combination anti-TNF and immunomodulatory medications.
The study investigators included a reference group that included exposure to 5-aminosalicylic acid or none of the medications listed here. Seroprotection was defined by HBsAb levels of ≥10 IU/L and ≥100 IU/L in this cohort.
A total of 391 patients with Crohn’s disease (64.2%) and ulcerative colitis (35.8%) were included in this retrospective analysis. More than half of the cohort (59.8%) had a prior HBV vaccination. The use of anti-TNF therapy was associated with a significantly lower chance of having seroprotective HBsAb titer levels of ≥10 IU/L vs no exposure to anti-TNF (46.3% seroprotection; odds ratio [OR], 0.42; 95% CI, 0.22-0.80; P <.01).
In addition, dual immunomodulator/anti-TNF therapy exposure was associated with a significantly reduced chance of having seroprotective HBsAb titer levels of ≥10 IU/L vs those not exposed to dual therapy (40.9% seroprotection; OR, 0.34; 95% CI, 0.19-0.62; P <.001).
Patients exposed to IFX were significantly less likely to have seroprotective HBsAb titer levels ≥10 compared with those not exposed to IFX or those exposed to adalimumab, methotrexate, 6-mercaptopurine, or azathioprine (35.5%; OR, 0.39; 95% CI, 0.22–0.68; P <.01).
This study is limited, in that it included patients with and without documented vaccination histories; therefore, prior vaccinations unaccounted for could have influenced the results. In addition, the retrospective nature of the study was only able to infer associations and not causality, which further limits the data.
Despite the study’s limitations, the data indicate that “patients exposed to IFX may comprise an increased risk group, and should be screened more frequently to ensure adequate HBsAb titers.”
Pratt PK Jr, David N, Weber HC, et al. Antibody response to hepatitis B virus vaccine is impaired in patients with inflammatory bowel disease on infliximab therapy. Inflamm Bowel Dis. 2018;24(2):380-386.