الفهرس 
DIABETES MELLITUSOnly 14 pages are availabe for public view
 |  | from | 186 |  |  |
| | | from | 186 | | |
Abstract
T
ype 1 diabetes (T1D) is a T cell mediated autoimmune disease that is associated with loss of immunological tolerance to self-antigens. The role of regulatory T cells in maintaining self tolerance has been intensively researched. It is considered that in the autoimmunologic reaction participate the disturbances in the number/function of T regulatory cells. The aim of study was to determine the percentages and count of T regulatory cells in the peripheral blood of children with type 1 diabetes.
The present study was a case control study, carried out at the Pediatric Diabetic Clinic of Children Hospital, Ain Shams University during the period from December 2010 till November 2011. A total of 40 children diagnosed with type 1 diabetes were studied, and compared to the control group consisted of 40 healthy children age and sex matched with no signs of autoimmune, chronic, inflammatory, neoplastic disease, and no evidence of T1D in their families. All patients were subjected to detailed history taking, thorough clinical examination and laboratory investigations including flowcytometric analysis of T-cell subpopulations performed using the following markers: anti-CD3, anti-CD4 and anti-CD25.
In the present study, (42.5%) (17 patients) of patients were males while 47.5% (23 patients) were females. The mean age of this study sample was 12.68±4.4 years with a range of 3 - 18 years in patient group, and the mean age of control group was 11.88±9.7 years with a range of 4 - 18 years. Informed Consent was obtained from all participants prior to the study.
To determine the size of the T regulatory cells population in patients with T1D and controls, the study analyzed the percentage of gated CD4+ T lymphocytes expressing CD25, patients had highly significant higher mean % CD4+CD25+high T- regulatory cells (10.42%) as compared to controls (3.9%), p- value was less than (0.01). However, the mean percentages of the other CD parameters (CD4+, CD4+CD25+) were not significantly different between both groups. There were significant differences in the total leucocytic count (TLC) and lymphocytic count between both groups, the mean percentage of CD3+ T- Lymphocytes was significantly higher among patients (63.3%) as compared to controls (57.65%) (p<0.05).
The relation between the glycemic control and mean CD4+CD25+high% was non significant (P>0.05), we divided the patient group into three groups according to the glycemic control:
- First group HbA1c less than 8
- Second group HbA1c 8 -10.
- Third group HbA1c more than 10.
A significant difference was found between the three groups as regards mean CD4+CD25+%, the mean CD4+CD25+ % of group 1 was (31.1%), while that of group 2 was (22.8 %), p- value was 0.04.
A strong positive association was found between CD4+CD25+high lymphocytes (%), CD4+CD25+ % and the age among the studied patients (r =0.47) and the p value was 0.002 and also as regards the association between sex and both CD4+CD25+% and CD4+CD25+high% was a highly significant correlation (r =39 , p =0.01).
Finally it was concluded that T1D is an autoimmune disease and there is a great deal of attention has been focused on the analysis of immunoregulatory function associated with T1D autoimmunity, based on the likelihood that a failure of immune regulation is required for complete immune-mediated beta cell loss. A number of contradictory observations confound this field, however.
The hypothesis of this study was not supported as there was increase in the percentage of T regulatory cells in patients than control.
The higher percentages of T regulatory in children with T1D found in this study need to be confirmed in larger studies and extended to delineate the defect in function. Further identification of these T cells may contribute to a better understanding of underlying mechanisms. The validation of more specific biomarkers for T regulatory cells, other than CD25, is needed, as this will facilitate the ability to monitor their cellular frequency and function in the context of T1D.