High seroprevalence against SARS-CoV-2 in non-vaccinated patients with inflammatory bowel disease from Northern India

BACKGROUND: The information on seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among patients with inflammatory bowel disease (IBD) and its comparison to healthy controls is sparse. We compared the seroprevalence rates in patients with IBD and healthy controls (HCs). METHODS: Patients with IBD and HCs (contact of patients) underwent SARS-CoV-2 antibody testing (chemiluminescent immunoassay: Siemens kit IgG against antigen-S1RBD) between July 2020 and April 2021. Information on demography, disease characteristics, drug history and past history of SARS-CoV-2 infection were noted. Patients on 5-aminosalicylic acid or no treatment were considered not on immunosuppressants and those who had received steroids, thiopurines or methotrexate within six months of inclusion were considered being on immunosuppressants. RESULTS: A total of 235 patients (51.9%, males; mean age, 38.7 ± 12.4 years; median disease duration, 60 months [interquartile range, IQR: 36–120]) (ulcerative colitis [UC]: 69.4%, Crohn’s disease [CD]: 28.9%, IBD unclassified [IBDU]: 1.7%) and 73 HCs (mean age, 39.6 ± 10.9 years, 80% males) were enrolled. Of the 235 patients, 128 (54.5%) patients were on immunosuppressants and 107 (45.5%) were not on immunosuppressants. Seventy-four (31.5%) patients were seropositive, of which two (0.9%) had previous history of SARS-CoV-2 infection and none received coronavirus disease-19 (COVID-19) vaccine. Seroprevalence between IBD patients and HCs (32% vs. 27%, p > 0.05) and between patients with and without immunosuppressants (28.1% vs. 36%, p > 0.05) was similar. Age, gender, disease type, duration and activity in the last six months; and medication use were similar between patients with positive and negative serology. There was a progressive increase in seroprevalence from July 2020 to April 2021. CONCLUSION: Up to 1/3rd of patients with IBD were seropositive for immunoglobulin G (IgG) SARS-Cov-2 antibody indicating high seroprevalence in patients with IBD from Northern India. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12664-022-01310-y.