Combination therapy of infliximab and thiopurines, but not monotherapy with infliximab or vedolizumab, is associated with attenuated IgA and neutralisation responses to SARS-CoV-2 in inflammatory bowel disease.

There is substantial interest regarding the perceived risk that immunomodulator and biologic therapy could have on COVID-19 disease severity among patients with inflammatory bowel disease (IBD) and clinicians. In this study, we show that infliximab/thiopurine combination therapy is associated with significantly lower IgA, a range of lower IgG responses as well as impaired neutralising antibody responses, compared to responses observed in healthy individuals. We also demonstrate that whilst IgG responses were significantly reduced in individuals with IBD treated with infliximab or vedolizumab monotherapy compared to healthy controls, there was no significant reduction in IgA and neutralising antibody responses. As neutralising antibody responses correlate with protection, this observation may provide the mechanistic explanation for the observation reported by the SECURE-IBD study that individuals on infliximab/thiopurine combination therapy were at greater risk of severe COVID-19 outcomes than patients on monotherapy.

Maintenance therapy with infliximab or vedolizumab in inflammatory bowel disease is not associated with increased SARS-CoV-2 seroprevalence: UK experience in the 2020 pandemic

BackgroundThere has been great concern amongst clinicians and patients that immunomodulatory treatments for IBD may increase risk of SARS-CoV-2 susceptibility or progression to severe disease. MethodsSera from 640 patients attending for maintenance infliximab or vedolizumab infusions between April and June 2020 at the John Radcliffe Hospital (Oxford, UK) and Royal London Hospital (London, UK) were tested using the Abbott SARS-CoV-2 IgG assay. Demographic and clinical data were collated from electronic patient records and research databases. ResultsSeropositivity rates of 3.0% (12/404), 7.2% (13/180), and 12.5% (7/56) were found in the Oxford and London adult IBD cohorts and London paediatric IBD cohorts respectively. Seroprevalence rates in the Oxford adult IBD cohort were lower than that seen in non-patient facing health-care workers within the same hospital (7.2%). Seroprevalence rates of the London paediatric IBD cohort were comparable to a contemporary healthy cohort collected at the same hospital (54/396, 13.6%). ConclusionsSARS-CoV-2 seropositivity rates are not elevated in patients with IBD receiving maintenance infliximab or vedolizumab infusions. There is no rationale based on these data for elective interruption of maintenance therapy, and we recommend continuation of maintenance therapy. These data do not address the efficacy of vaccination in these patients.