P368. Serological response to the 23-valent pneumococcal polysaccharide vaccine in patients with Crohn's disease: preliminary results of a prospective, multicentre study
C.K. Lee1, H.-S. Kim2, H.-J. Kim1, W. Moon3, K.M. Lee4, J.-S. Koo5, G.S. Seo6, S.J. Park7, B.D. Ye8, C.H. Choi9, S.-A. Jung10, Y.S. Kim11, J.P. Im12, E.S. Kim13, S.N. Hong14, 1Kyung Hee University, South Korea, 2Yonsei University Wonju College of Medicine, South Korea, 3Kosin University, South Korea, 4The Catholic University of Korea, South Korea, 5Korea University, South Korea, 6Wonkwang University, South Korea, 7Yonsei University, South Korea, 8University of Ulsan, South Korea, 9Chung-Ang University, South Korea, 10Ewha Womans University, South Korea, 11Inje University, South Korea, 12Seoul National University, South Korea, 13Keimyung University, South Korea, 14Konkuk University, South Korea
Recent studies have reported that anti-tumour necrosis factor (anti-TNF) blockers alone or in combination with immunomodulators (IM) can impair the serological response to pneumococcal vaccination in patients with inflammatory bowel disease (IBD). However, the type of IBD might have been a potential confounding factor in the previous studies. Therefore, we evaluated the effect of immunosuppressive treatment on the serological response to and safety of the 23-valent pneumococcal polysaccharide vaccine in patients with Crohn's disease.
This is part of an on-going prospective, multicentre, observational study. Of 180 patients enrolled, 171 completed the study. The study population belonged to one of the following four treatment groups: 5-aminosalicylate alone (control group, n = 37), IM alone (IM group, n = 70), anti-TNF blocker alone (anti-TNF group, n = 14), and anti-TNF blocker in combination with IM (combination group, n = 50). Anti-pneumococcal IgG antibody titres were measured before and 4 weeks after vaccination. The primary outcome was the serological response rate, defined as the proportion of patients achieving both a ≥ twofold increase in baseline titres and a post-vaccination geometric mean titre (GMT) ≥1 µg/mL. The secondary outcome was the difference in the GMTs prior to and after vaccination. All vaccination-related adverse events up to 4 weeks after vaccination were recorded. This study is registered at www.clinicaltrials.gov (NCT01505855).
The overall serological response rate was 70.8% (121/170). Only the combination group had a significantly lower serological response rate than did the control group (58.0% vs. 78.4%, P < 0.05). The post-vaccination GMTs of the immunosuppressed patients were significantly lower than that of the non-immunosuppressed patients (P < 0.001). The post-vaccination GMTs did not differ significantly among the IM, anti-TNF, and combination groups (P > 0.05). Vaccination was generally safe and well-tolerated by all patients.
Only treatment with the combination of anti-TNF and IM led to impaired seroprotection to pneumococcal vaccination in patients with Crohn's disease. Patients receiving immunosuppressive therapies had significantly lower post-vaccination GMTs than did non-immunosuppressed patients, suggesting that the use of immunosuppressive medications, regardless of their types, could be a potential cause of suboptimal response to pneumococcal vaccination.