[Circulating populations of CD4+ CD25+ CD127- regulatory t lymphocytes in peripheral blood of allergic asthmatic children].

Objective: To carry out a preliminary analysis on the Treg lymphocyte counts present in the peripheral blood of allergic asthmatic children from the city of Cartagena, Colombia, compared to healthy controls.

Methods: We compared cytometry counts of ten asthmatic patients (age 7-16 years) and seven healthy controls (6-12 years), recruited in the city of Cartagena. Peripheral blood samples were stained using Cytek's 14-color cFluor Immunoprofiling kit (Cytek^® cFluor^® Immunoprofiling Kit 14 Color RUO kit), and analyzed on a Northern Lights™ spectral cytometer (Cytek^® Biosciences, Fremont, CA, USA), to read 50.000 events per sample. The data obtained were analyzed in SpectroFlo^® and FlowJo. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405).

Results: The frequency of CD3+, CD4+, CD25+, CD127- Tregs was 11% of all CD4+ T cells, with a range of minimum 8,1% and maximum 17,7%. There was no significant difference in the proportion of Tregs between allergic asthmatic patients and healthy controls (P = 0,2).

Conclusions: With this preliminary sample size, no significant differences were found in the Treg lymphocyte population between allergic asthmatic patients and healthy controls. The 14-color multiplexed panel is a useful tool not only to count CD3+ and CD4+ populations, but also to obtain the percentage of regulatory T cells using cell surface markers.