BACKGROUND: Alteration of regulatory T cells (Tregs) may contribute to 
ineffective suppression of proinflammatory cytokines in type 1 diabetes.
AIM: We determined the percentage of Tregs expressing CD62L or tumor necrosis 
factor receptor type 2 (TNFR2) in 70 young type 1 diabetic patients compared 
with 30 controls and assessed their relation to inflammation, glycemic control 
and micro-vascular complications.
METHODS: High-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c (HbA1c), 
tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) were assessed 
with flow cytometric analysis of Tregs, Tregs expressing CD62L or TNFR2.
RESULTS: The percentage of CD4(+)CD25(high) T cells and 
CD4(+)CD25(high)CD62L(high) cells were significantly decreased while 
CD4(+)CD25(high)TNFR2(+) T cells were elevated in patients with micro-vascular 
complications than those without and controls (p<0.001). ROC curve revealed that 
the cutoff values of Tregs, Tregs expressing CD62L and Tregs expressing TNFR2 
(7.46%, 24.2% and 91.9%, respectively) could detect micro-vascular 
complications. Significant negative correlations were observed between Tregs 
expressing CD62L and disease duration, FBG, HbA1c, urinary albumin excretion and 
hs-CRP, whereas, positive correlations were found between Tregs expressing TNFR2 
and these variables (p<0.05). TNF-α was significantly increased while IL-10 was 
decreased among patients with micro-vascular complications than those without 
(p<0.05).
CONCLUSIONS: Alteration in the frequency of Tregs and Tregs expressing CD62L or 
TNFR2 in type 1 diabetes is associated with increased inflammation, poor 
glycemic control and risk of micro-vascular complications.