AIM: To observe the change law of the ratio of CD4⁺ CD25⁺ regulatory T cell in the peripheral blood of the patients with Graves' ophthalmopathy by detecting the ratio of this cell.

METHODS: This experimental study selected 53 GO patients without exophthalmos, 51 GO patients with exophthalmos, and 51 healthy people were collected. The ratio of CD4⁺CD25⁺ T cell in peripheral blood was determined by flow cytometry.

RESULTS: The ratio of CD4⁺CD25⁺ T cell in GO patients without exophthalmos was lower than that in healthy group(P<0.01). The ratio of CD4⁺CD25⁺ T cell in GO patients with exophthalmos was far lower than that in healthy group(P<0.01). Compared with the group of GO patients without exophthalmos, the ratio of CD4⁺ CD25⁺ T cell of GO patients with exophthalmos was also much lower(P<0.01).

CONCLUSION: The ratio of CD4+ CD25+ T cell in the GO patients decreases and there is autoimmune disorder in patients of this disease. Perhaps this is an important mechanism causing immune suppression damage, which provides a new clue for immunological treatment.