Circulating‐Peripheral Blood Naturally Occurring CD4+CD25+ Regulatory T Cells and CD4+ T Cells in Chronic Rheuma

Background: The development of autoimmune disease involves a breakdown in the mechanisms that control T cell tolerance to self antigens, these mechanisms are many and complex, and they integrate as immunoregulation. Among the cells that might be responsible for this regulation is a specific type of T cells which has the ability to downregulate the differentiation of helper cells or antigen specific effector cells. The main subset of these suppressor T cells is the naturally occurring CD4+CD25+ regulatory T cells (n Tregs) which are the most important and they derived as a functionally mature population from the thymus.
Objective: The purpose of this study was to determine the correlation between the numbers of circulating CD4+CD25+ regulatory T cells (nTregs) and CD4+ T cells in chronic rheumatic heart disease patients.
Methods: Peripheral blood samples were taken from 48 Iraqi patients with chronic rheumatic heart disease (CRHD). Lymphocytes were isolated from the peripheral blood, nTregs and CD4+ T cells; also, cell numbers were detected by using immunofluorescence technique.
Results: In general, nTregs were found in lower numbers in the peripheral blood of CRHD patients in different study groups than in healthy control group, whereas, CD4+ T cells were found in higher numbers in some of patients than controls. Also, our results revealed that there was a significant negative correlation between naturally occurring CD4+CD25+ regulatory T cells and CD4+ T cells in all study groups.
Conclusions: Our finding confirmed that there is a significant correlation between circulating nTregs and CD4+ T cells in chronic rheumatic heart disease.
Key words: CD4+CD25+ regulatory T cells, CD4+ T cells, chronic rheumatic heart disease.