Examining multi‐level immune response to determine prevalence of COVID‐19 in pediatric tonsillectomy

Abstract

Objective To determine the prevalence of COVID‐19 in a cohort of children undergoing tonsillectomy through assessment of B cell immune responses to SARS‐CoV‐2 in both peripheral blood and tonsil tissue. Methods In this cohort study at a tertiary pediatric hospital (Children's National Hospital) in Washington, DC, we recruited 100 children undergoing tonsillectomy from late September 2020 to January 2021. Serum, peripheral blood cells, and tonsil tissue were collected and examined for immune reactivity to SARS‐CoV‐2. Parent‐reported clinical histories were compared to antibody and B‐cell responses. Results Among 100 children undergoing tonsillectomy, 19% had evidence of immune responses to SARS‐CoV‐2 (CoV2+), indicating prior COVID‐19. In all seropositive participants, we detected SARS‐CoV‐2 specific B cells in both peripheral blood mononuclear cells and tonsils, providing evidence for tissue‐specific immunity in these children. Of the 19, 63% reported no known history of COVID‐19, and an additional 3 were asymptomatic or unaware of an acute infection when detected on pre‐surgery screen. Hispanic children represented 74% of CoV2+ subjects compared to 37% of the full cohort. 100% of CoV2+ children lived in a zip code with poverty level >10%. Conclusions Nearly one‐fifth of children undergoing tonsillectomy at an urban U.S. hospital had evidence of prior COVID‐19 during the early pandemic, with the majority unaware of prior infection. Our results underscore the ethnic and socio‐economic disparities of COVID‐19. We found concordant evidence of humoral immune responses in children in both blood and tonsil tissue, providing evidence of local immune responses in the upper respiratory tract. Level of Evidence 3 Laryngoscope , 2022

Robust memory humoral immune response to SARS-CoV-2 in the tonsils of adults and children

“…On the other hand, anti-N was slightly induced in all stimulated TMNCs compared to unstimulated cells with only a 3.5- and 3.6-fold increase in adults and children, respectively. Interestingly, the same level of induced IgG response was also found in the children with no known history of infection (C6, C8, and C10) ( Table 1 ), suggesting that these participants might have been indeed previously exposed to SARS-CoV-2 or other coronaviruses ( 36 ).…”

Adaptive immune responses to SARS-CoV-2 persist in the pharyngeal lymphoid tissue of children

“…Using samples from pediatric tonsillectomies and adenectomies, we found evidence of persistent immune responses to SARS-CoV-2 in the pharyngeal lymphoid tissues, including antigen-specific memory B and T cells and prolonged changes in lymphocyte populations after infection. The high percentage of seropositive children in our cohort in late 2020 to early 2021, before vaccine availability, underscored the extent of COVID-19 in this urban population 36 . The variation in memory B cell frequencies and serum-neutralizing antibody titers we observed further highlighted heterogeneity of responses that may leave some children prone to repeat infection.…”