Immunosuppression Impairs Response to Pneumococcal Polysaccharide Vaccination in Patients With Inflammatory Bowel Disease

Abstract

The treatment of inflammatory bowel disease (IBD) often includes immunosuppressive medications, which may increase the risk of vaccine-preventable illnesses. We aimed to assess the impact of immunosuppression on immune responses to pneumococcal vaccination in patients with IBD. The study design consists of a prospective controlled clinical trial. This study was carried out at a tertiary-care IBD clinic. The subjects for the study belonged to one of the following three groups: adult patients with IBD on combination TNF-blockers and immunomodulators (Group A), those without immunosuppressive therapy (Group B), and age-matched healthy controls (Group C). The treatment consisted of immunization with 23-valent pneumococcal polysaccharide vaccines (PSVs). The main outcome was immune response for five serotypes defined as a twofold or greater increase from pre-vaccination titers and > or =1 microg post-vaccination titer. Sixty-four subjects participated in the study: 20 in Group A, 25 in Group B, and 19 in Group C. Pre-vaccination titers were similar among the three groups. Vaccine responses were lower in Group A than in Group B (P< or =0.01 for four out of five antigens) and Group C (P<0.01 for all five antigens). Overall vaccine response was seen in 45, 80, and 85% of Groups A, B, and C (P=0.01), respectively. Immune response to PSV-23 is impaired in Crohn's disease (CD) patients on combination immunosuppressive therapy but is normal among non-immunosuppressed patients. Given the unpredictable likelihood for immunosuppressive therapy, newly diagnosed patients with IBD should undergo vaccination before the initiation of immunosuppressive therapy.