SARS‐CoV‐2 (COVID‐19)‐specific T cell and B cell responses in convalescent rheumatoid arthritis: Monozygotic twins pair case observation

Rheumatoid arthritis (RA) patients present higher risk of SARS‐CoV‐2 infection (COVID‐19), and proper management of the disease in this population requires a better understanding of how the immune system controls the virus. We analyzed the T cell and B cell phenotypes, and their repertoire in a pair of monozygotic twins with RA mismatched for COVID‐19 infection. Twin‐ was not infected, while Twin+ was infected and effectively controlled the infection. We found no significant changes on the αβ T cell composition, while γδ T cells and B cells presented considerable expansion of memory population in Twin+ and robust T/B cell responses to several SARS‐CoV‐2 peptides. T cell receptor β/γ‐chain and immunoglobulin heavy chain next‐generation sequencing depicted a remarkable higher diversity in Twin+ compared with Twin‐, despite no significant changes being found in variable/joining family usage. Repertoire overlap analyses showed that, although being identical twins, very few clones were shared between them, indicating that COVID‐19 may lead to deep changes on the immune cell repertoire in RA patients. Altogether, our results indicate that RA patients may develop robust and persistent COVID‐19‐specific T/B cell responses; γδ T cells and B cells may play a key role in the management of COVID‐19 in RA, and the infection may lead to a profound reshaping of immune cell receptor specificities.