SPECIFIC IMMUNOGLOBLIN A INDUCED BY THE PERSISTENT COLONIZATION OF ADHERENT-INVASIVE E.COLI LIMITS PATHOBINT LOCALIZATION TO THE EPITHELIAL NICHE

BACKGROUND: Immune-modulating medications for inflammatory bowel diseases (IBD) have been associated with suboptimal vaccine responses.There is conflicting data with SARS-CoV-2 vaccination.METHODS: We measured SARS-CoV-2 vaccine immunogenicity at 2 weeks post 2 nd mRNA vaccine in IBD patients as compared to normal healthy donors (NHD).We measured humoral immune responses to SARS-CoV-2: anti-spike Immunoglobulin G (IgG) and anti-receptor binding domain (RBD) IgG were measured by ELISA, and neutralizing antibody titers were measured using recombinant, reporter SARS-CoV-2.Antigen specific memory B cells were measured using recombinant SARS-CoV-2 proteins.Activation induced marker T cell (AIM) assays were performed using SARS-CoV-2 spike megapools.Immunophenotyping was performed by flow cytometry.RESULTS: We enrolled 29 patients with IBD (19 with Crohn's disease, 10 with ulcerative colitis) on infliximab (IFX) monotherapy (N=9), IFX combination therapy with a thiopurine (N=9), vedolizumab monotherapy (N= 11) as compared to matched NHD (N=12).At 2 weeks post vaccination, all subjects made detectable anti-spike IgG and anti-RBD IgG.There were no differences in anti-spike IgG titers among the different groups.IBD patients on IFX monotherapy, but not IBD patients on IFX combination therapy or vedolizumab monotherapy, had lower anti-RBD and neutralization titers as compared to NHD (p-value: 0.041 and 0.023, respectively) (Fig. 1).There were no significant differences in the percentage of spike-specific or RBD-specific memory B cells in IBD patients as compared to NHD (Fig. 1).There were no differences in the percentage of spike-specific CD4 + or CD8 + T cells in all IBD patients as compared to NHDs (Fig. 2).CONCLUSIONS: We demonstrate overall comparable and perserved cell-mediated immunity to SARS-CoV-2 vaccination in a small cohort of IBD patients treated with a range of different immune-modulating medications as compared to healthy controls.Larger numbers of patients are needed to validate these findings.