Role of CD4+CD25+ T cells in children with idiopathic thrombocytopenic purpura.

BACKGROUND

CD4CD25 T cells play an important role in the induction and maintenance of peripheral self-tolerance. These professional regulatory cells prevent the activation and proliferation of potentially autoreactive T cells that have escaped thymic deletion.

OBJECTIVE

To investigate the role of CD4CD25 regulatory T cells in children with idiopathic thrombocytopenic purpura (ITP) and correlate their levels with different disease stages, this study was conducted in 45 children (15 controls and 30 cases with ITP); 10 of these patients were in the acute phase (Group I), 10 in the remission phase (Group II), and the remaining 10 in the chronic phase (Group III).

METHODS

Studied groups were subjected to the following investigations: complete blood count, erythrocyte sedimentation rate, Coombs test, and flow cytometric analysis of CD4CD25 T lymphocyte count.

RESULTS

There was a highly significant decrease in platelet count and CD4CD25 count in patients of the acute group when compared with remission, chronic, and control groups. There was a significant decrease in CD4CD25 count in the chronic group when compared with remission group. In addition, a significant decrease in CD4CD25 count was found in remission group when compared with the control group. Moreover, there was a positive correlation between CD4CD25 count and platelet count in all the groups; this correlation was significant in the acute group and insignificant in the remission and chronic groups.

CONCLUSIONS

Decreased number of CD4CD25 T cells might be one of the mechanisms that cause immune regulation dysfunction in ITP and the count of CD4CD25 T cells is considered to be related to the severity of ITP, as these cells were significantly decreased in the active phase of the disease and increased in the patients at the complete remission phase. Therefore, count of CD4CD25 T cells might be a helpful diagnostic predictor of onset and improvement of ITP in children. Finally, it is suggested that these cells may have therapeutic implications that need further clarification.