Role of regulatory T-cells in the development of the partial remission period in patients with type 1 diabetes
Tatiana Nikonova, Vera Gorelysheva, Sergey Prokofiev, Elena Pekareva & Ivan Dedov
Background and aims: Remission period in type 1 diabetes (T1D), also known as the honeymoon period has been acknowledged as an advantageous time for immune intervention. However, not all subjects will go through this remission phase. It was suspected that defects in regulatory T-cells number and activity are causally related to the development of T1D.
The aim of the study was to find specific T-cell assay that reflects remission period.
Materials and methods: Twenty-three patients with T1D were examined in dynamics during the first 3 years of the disease. Also 17 at-risk subjects and eight control subjects were examined.
The HLA-DR and DQ alleles were detected by SSPPCR method. CD3+, CD4+, CD8+, CD25, CD4+CD25+, CD38, LTDRB and CD20 cells were analyzed by flow cytometry.
Inclusion criteria for control subjects were random blood glucose <5.6 mmol/l, no history of any autoimmune disorder including T1D in the family and an absence of T1D-specific autoantibodies (aAbs). At-risk subjects had specific aAbs and were unrelated to the patients included in this study. T1D subjects were defined according to WHO criteria.
Results: A rising tendency of CD25+ (%) and CD4+CD25+ (%) T-cells between control and at-risk subjects was observed (P<0.1). Significant differences were found in content of CD38 and LTDRB cells (P<0.05) in those groups. Increased values of CD25+ and CD4+T-cells (P<0.05) were detected in the group of T1D patients with duration of diabetes <6 months. These values were associated with development of partial remission (HbA1c<7%; insulin requirement ≤0.4 units/kg per 24 h) and increased C-peptide levels (P<0.1). On the contrary, in longer standing T1D (>1 year) as compared with previous group in majority of the patients CD25+ and CD4+CD25+T-cells levels were reduced (P<0.05).
Conclusion: These results suggest that increased regulatory T-cells values seen in the recent onset T1D can be considered as a remission marker.