[The surface CD152 (CTLA-4) expression on peripheral blood lymphocytes in children with Hashimoto's thyroiditis].

Introduction: The cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a transmembrane molecule present on T cells that plays a critical role in the down regulation of antigen-activated immune response. Its gene polymorphism is a strong candidate gene for conferring susceptibility to thyroid autoimmunity. THE AIM of the study was to analyse the surface CTLA-4 (CD 152) expression on peripheral blood lymphocytes.

Material and methods: Blood samples from 66 children were analysed: 36 with Hashimoto's thyroiditis and 30 healthy, age-matched controls, mean age: 13.4 years. The percentages of peripheral blood lymphocyte subsets were analysed by evaluation of CD antigens surface expression with three colour flow cytometry using Coulter EPICS XL cytometer. CD28, CD152, CD4, CD8 antigens were evaluated. Statistical analysis was performed using t- test and other tests of the Statistica programme. P-value <0.05 was considered as statistically significant.

Results: In children with Hashimoto's thyroiditis the surface expression of CD8(+) CD152(+) T cells was statistically significant lower than in healthy controls. P-value was 0,02. Percentage of other CD examined in the study did not differ significantly in patients and in the control group.

Conclusion: In children with Hashimoto's thyroiditis the surface expression of CTLA-4 (CD152) on peripheral blood lymphocytes CD8(+) was statistically significantly lower than in healthy controls.