Frequency of CD4+CD25hiFOXP3+ Regulatory T Cells in Type 1 Diabetes Mellitus

Background: Regulatory T cells (Tregs) characterized by CD4, CD25, and transcription factor forkhead box P3 (FOXP3) play a crucial role in maintaining peripheral tolerance. Type 1 diabetes mellitus (DM1) is characterized by destruction of pancreatic islets by auto-reactive T cells. Recently, the role of Tregs in the pathogenesis of DM1 has been interrogated. Objectives: The current study was conducted to determine the percentage of CD4+CD25hiFOXP3+ Tregs in patients with DM1. Patients and methods: This case-control study included 32 patients suffering from DM1 selected from the Outpatient Clinic of Diabetes Mellitus of the Specialized Internal Medicine Hospital, Mansoura University, Mansoura, Egypt. Further 24 age- and gender-matched healthy subjects were enrolled as a control group. Flow cytometric analysis was performed for evaluation of the percentage of CD4+CD25hiFOXP3+ Tregs in the peripheral blood samples of patients with DM1, as well as control subjects. Results: Patients with recent onset DM1 had reduced percentage of CD4+CD25hiFOXP3+ Tregs compared to patients with established disease [p = 0.02], and control subjects [p = 0.0001]. Nevertheless, no statistically significant difference was detected between patients with established disease and control subjects [p > 0.05]. Conclusion: The percentage of CD4+CD25hiFOXP3+ Tregs is reduced in patients with DM1 compared to control subjects. However, these findings need to be evaluated in a larger cohort of patients to validate results.