Frequency of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in peripheral blood of pediatric patients with SARS CoV-2 Infection: a pilot study

Background: Cytokine storm has been observed in some patients with SARS-CoV-2 due to excessive pro-inflammatory response. Foxp3(+) regulatory T cells (Tregs) are a distinct population of CD4(+) lymphocytes identified by their expression transcription factor forkhead homeobox protein-3 (Foxp3). These down-regulate immune responses inflammatory and autoimmune diseases. Objective: This pilot study was aimed investigate the levels CD4(+)CD25(+)Foxp3(+) Tregs children SARS-CoV-2. Methods: frequency measured flow cytometry 20 SARS-CoV-2, 6 months 15 years old;6 had COVID-19 14 multisystem syndrome (MIS-C). They were compared age-and sex-matched healthy as control group. Results: There no significant difference between infection (P=0.068). Decreased numbers found only 10% patients. Patients severe comparable those moderate disease terms Tregs' levels. The correlated negatively neutrophil counts our series (p=0.036). Attempts correlation other markers insignificant. Conclusion: infected children. did not correlate severity or routine Thus, does seem have role up-regulated response seen infection. Our conclusions limited sample size.