The determination of Regulatory T lymphocytes (Tregs) allows for the evaluation of allergy and autoimmune conditions, as well as the monitoring of chronic and neoplastic diseases. Regulatory T lymphocytes are responsible for suppressing inflammation and controlling the development of autoimmune diseases.

A decrease in the frequency of regulatory T lymphocytes, as well as a change in the phenotype of these cells, has been linked to a limited suppressive capacity in controlling the effector response in inflammation or cancer, or an increase in reactivity against self-cells. The control and regulation of these cells in the immune system is very important.