SARS-CoV-2 specific immune responses in overweight and obese COVID-19 patients

• Published in: Frontiers in immunology Vol. 14; p. 1287388
• Main Authors: Onyango, Therese Bredholt, Zhou, Fan, Bredholt, Geir, Brokstad, Karl A, Lartey, Sarah, Mohn, Kristin G-I, Özgümüs, Türküler, Kittang, Bård Reiakvam, Linchausen, Dagrun Waag, Shafiani, Shahin, Elyanow, Rebecca, Blomberg, Bjørn, Langeland, Nina, Cox, Rebecca Jane
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 2023
• Subjects: Antibodies, Neutralizing; Antibodies, Viral; cellular; COVID-19; COVID-19 Vaccines; Enzyme-Linked Immunospot Assay; Humans; Immunity; Immunoglobulin G; Interleukin-2; neutralising; obesity; Obesity - complications; Overweight; Prospective Studies; SARS-CoV-2; spike; COVID-19; TCR; cellular; neutralising; overweight; obesity; spike; vaccination
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2023.1287388

Obesity is a known risk factor for severe respiratory tract infections. In this prospective study, we assessed the impact of being obese or overweight on longitudinal SARS-CoV-2 humoral and cellular responses up to 18 months after infection. 274 patients provided blood samples at regular time intervals up to 18 months including obese (BMI ≥30, n=32), overweight (BMI 25-29.9, n=103) and normal body weight (BMI 18.5-24.9, n=134) SARS-CoV-2 patients. We determined SARS-CoV-2 spike-specific IgG, IgA, IgM levels by ELISA and neutralising antibody titres by neutralisation assay. RBD- and spike-specific memory B cells were investigated by ELISpot, spike- and non-spike-specific IFN-γ, IL-2 and IFN-γ/IL-2 secreting T cells by FluoroSpot and T cell receptor (TCR) sequencing was performed. Higher BMI correlated with increased COVID-19 severity. Humoral and cellular responses were stronger in overweight and obese patients than normal weight patients and associated with higher spike-specific IgG binding titres relative to neutralising antibody titres. Linear regression models demonstrated that BMI, age and COVID-19 severity correlated independently with higher SARS-CoV-2 immune responses. We found an increased proportion of unique SARS-CoV-2 specific T cell clonotypes after infection in overweight and obese patients. COVID-19 vaccination boosted humoral and cellular responses irrespective of BMI, although stronger immune boosting was observed in normal weight patients. Overall, our results highlight more severe disease and an over-reactivity of the immune system in overweight and obese patients after SARS-CoV-2 infection, underscoring the importance of recognizing overweight/obese individuals as a risk group for prioritisation for COVID-19 vaccination.