AUTHOR=Pavan Kumar Nathella , Abbas Kadar M. , Renji Rachel M. , Venkataraman Aishwarya , Nancy Arul , Varadarjan Poovazhagi , Selladurai Elilarasi , Sangaralingam Thankgavelu , Selvam Ramya , Thimmaiah Akshith , Natarajan Suresh , Ramasamy Ganesh , Hissar Syed , Ranganathan Uma Devi , Nutman Thomas B. , Babu Subash 

TITLE=Multisystem inflammatory syndrome in children characterized by enhanced antigen-specific T-cell expression of cytokines and its reversal following recovery

JOURNAL=Frontiers in Pediatrics

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2023.1235342

DOI=10.3389/fped.2023.1235342

ISSN=2296-2360

ABSTRACT=Background: Multisystem Inflammatory Syndrome in Children (MIS-C) is considered to be a post-infectious complication of COVID-19. T cell responses in MIS-C children have not been well-studied. 
Methods: We aimed to study the immune responses in children with MIS-C in comparison to children with acute COVID-19 and children with other infections. Whole blood was stimulated with SARS-CoV-2-specific antigens and flow cytometry was performed to examine CD4+ and CD8+ T cell responses. 
Results: Children with MIS-C had higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen-specific stimulation in comparison to children with COVID-19 and/or other infections. COVID-19 children also exhibited higher frequencies of CD4+ and CD8+ T cells expressing cytokines at baseline and upon SARS-CoV-2 antigen-specific stimulation in comparison to children with other infections. At 6 to 9 months following treatment and recovery, this enhanced response against SARS-CoV-2 antigens was down modulated in MIS-C. 
Conclusion: Our study, therefore, provides evidence of enhanced activation of CD4+ and CD8+ T cell responses in MIS-C in children and reversal following recovery