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P484 Hepatitis B vaccination in inflammatory bowel disease

J. Cortez Pinto*1, J. Castela1, J. Moleiro1, J. Pereira da Silva1, I. Rosa1, A. Dias Pereira1

1Instituto Português de Oncologia de Lisboa Francisco Gentil, EPE, Gastroenterology, Lisboa, Portugal

Background

Inflammatory bowel disease (IBD) patients have a lower response to hepatitis B virus (HBV) vaccination, especially those receiving anti-TNF treatment. It has been suggested that modified dosing regimens may increase response rates in these patients. Our aim was to evaluate the efficacy of HBV vaccination in an IBD cohort as well as to identify the absence of response predictive factors. We also evaluated a revaccination protocol in patients who failed seroconversion with the standard regimen.

Methods

Single-centre prospective observational study. All patients with IBD were evaluated for serological markers of HBV. The single dose HBV vaccine was administered at 0, 1 and 6 months to all seronegative patients. Subsequent determination of the anti-HBs antibody was recorded. An adequate immune response (AIR) to HBV was defined as more than 10 mIU/ml. A single booster regimen was administered to patients without AIR. A double-dose administration of the vaccine was administered at 0, 1 and 6 months to patients without AIR to the booster. We analysed AIR in patients with IBD in general and according to the therapeutic regimens (thiopurines and / or anti-TNF). The efficacy of the different vaccination regimens was also evaluated. Statistics - Chi-square and Exact tests.

Results

118 IBD patients were evaluated [(43% males; mean age 52.5 years (20–80)], of which 55.8% with Crohn’s disease. 47.5% were on immunosuppressive therapy (40% of them on biologic agents). 31.7% had already been vaccinated and 35% were immune (Anti-HBs positive) to HBV. In the subgroup of patients previously vaccinated 13% (5 patients – 2 on thiopurines and 2 on anti-TNF) were not immune and 2 did not respond to booster vaccination. With respect to vaccination-naïve patients, seroconversion with standard protocol was significantly lower in those under immunosuppressive therapy (36% vs. 71%; p = 0.03). A tendency for a lower response was also identified in older patients at Crohn’s disease diagnosis (Montreal A3: 25% vs. Montreal A1/ A2: 52%; p = 0.159). A patient with AIR lost immunity under immunosuppressive therapy and regained it after a booster.

Conclusion

The response rate of IBD patients to HBV standard protocol vaccination was significantly lower in those under immunosuppressive therapy. AIR needs to be regularly assessed and booster vaccination seems effective in a subgroup of patients.