Background: Infliximab (IFX) and adalimumab (ADA) cross the placenta in the third trimester and can be detectable in infants for up to 12 months.
Aim: The aim of this study was to determine whether in utero IFX or ADA exposure results in an impaired immune response in infants, as measured by immunoglobulin levels and antibody responses to routine primary immunizations.
Methods: Infants who were exposed to in utero anti-TNFα agents were prospectively evaluated. Immunoglobulin levels (IgG, IgM, IgA) and antibodies to standard vaccinations, including tetanus toxoid (tetanus) and Haemophilus influenza type b (Hib), were measured in infants of at least 6 months of age.
Results: Twelve infants were prospectively studied: 10 exposed to in utero IFX and 2 exposed to ADA with at least one dose administered in the third trimester. Immunoglobulin levels were available on 10/12 patients, with all showing adequate immunoglobulin levels, except for low IgM levels in 5 (50 %) infants. Adequate responses to both the tetanus and Hib vaccines were seen in 11 of 12 (92 %) infants.
Conclusions: Infants exposed to anti-TNFα agents in utero demonstrate appropriate response to two commonly administered neonatal vaccines and show adequate immunoglobulin levels, except for IgM. Newborns with a history of exposure to anti-TNFα agents should follow a standard vaccination schedule for inactive vaccines.
Keywords: Anti-TNFα; Immune response; Inflammatory bowel disease; Pregnancy.