Antibody Response in IBD Patients After COVID Infection

August 5, 2021

Canadian researchers at the University of Calgary have published a study testing the antibody response after a COVID-19 infection in those with inflammatory bowel disease (IBD).

Many IBD patients take immunosuppressive therapies for their autoimmune disease, which may inhibit the development of antibodies after a COVID-19 infection or the vaccine. This population is also considered high-risk for severe disease outcomes from a COVID-19 infection.

Serosurveillance provides estimates of antibody levels against infectious diseases and is considered the gold standard for measuring population immunity due to past infection or vaccination. This serosurveillance study included 324 patients from October 2020 to April 2021; 279 patients were in the serosurveillance group and did not have a prior COVID-19 diagnosis. 45 patients had been previously infected and recovered from COVID-19. The majority of participants had Crohn’s disease; 60% of recovered patients and 48.5% of the serosurveillance group were on anti-TNF agents.

At baseline, 53.3% of recovered patients had positive nucleocapsid antibodies, whereas 1.08% of the serosurveillance cohort tested positive. Nucleocapsid proteins are the most sensitive target for serologicical diagnosis of a COVID-19 infection; neutralizing antibodies appear later in immune development (1).

“The proportion of patients who were nucleocapsid antibody positive was 80.9% from 0-90 days from diagnosis.” Only 21.7% of patients tested positive for antibodies after 90 days post-infection.