No expansion of MIS-c associated TCR Vβ 21.3⁺ T-cells in pediatric Post-COVID condition

Area of Science:

• Immunology
• Pediatrics
• Virology

Background:

• Pediatric post-COVID Condition (PPCC) etiology is unknown.
• Multisystem Inflammatory Syndrome in Children (MIS-C) is a known SARS-CoV-2 complication.
• MIS-C involves expansion of polyclonal TCR Vβ 21.3+ (TRBV11-2) T-cells.

Purpose of the Study:

• To investigate the T-cell Vβ 21.3 expression in PPCC.
• To compare T-cell profiles in PPCC, MIS-C, acute COVID-19, and healthy children.
• To explore potential shared or distinct pathophysiologies between PPCC and MIS-C.

Main Methods:

• Flow cytometry analysis.
• Quantification of TCR Vβ 21.3+ T-cells within activated HLA-DR+/Ki67+ T-cells.
• Study included 86 PPCC, 32 MIS-C, 7 acute COVID-19, and 15 healthy pediatric controls.

Main Results:

• 78% of MIS-C patients (25/32) showed enrichment of Vβ21.3+ T-cells within activated T-cells.
• No enrichment of Vβ21.3 expressing cells was observed in PPCC patients.
• T-cell profiles differed significantly between MIS-C and PPCC groups.

Conclusions:

• The findings argue against a shared T-cell expansion pathophysiology between MIS-C and PPCC.
• Distinct immune responses may underlie different post-COVID conditions in children.
• Further research is needed to elucidate PPCC pathogenesis.