Objective: To investigate the relationship between intrathyroidal dendritic cells and humoral immune disorder in Graves' disease.
Methods: With the use of S-100 protein antibodies and the help of SP immunohistochemical method, the number and distribution of S-100 protein positive dendritic cells were observed in thyroid glands from 34 patients with Graves' disease and 5 controls. Serum thyroid stimulating antibodies (TSAb) before operation were measured with human embryo-kidney cells expressing the recombinant thyrotrophin receptor. The correlation between the infiltrating degree of intrathyroidal dendritic cells and the values of serum TSAb was analyzed in patients with Graves' disease.
Results: In normal thyroid glands, no S-100 protein positive dendritic cells were found. Dendritic cells were seen in all observed thyroid glands from patients with Graves' disease. Most of the dendritic cells were seen in close contact with the adjacent thyroid epithelial cells or infiltrating lymphocytes. The infiltrating degree of intrathyroidal dendritic cells in Graves' disease correlated closely with the values of serum TSAb (r = 0.4461, P < 0.01).
Conclusion: It is suggested that the intrathyroidal dendritic cells have a close relation with humoral immune disorder and play an important role in the initiation and/or maintenance of thyroid autoimmune reaction in Graves' disease.