Activated (Ia+) T-cells and their subsets in Graves' disease and Hashimoto's thyroiditis using dual laser flow microfluorocytometric analysis.

UNLABELLED

Lymphocytes from patients with Graves' disease and Hashimoto's thyroiditis were analysed directly by a dual laser-activated cell-sorter for the percentage of activated T-cells and their subsets using two-colour dye-labelling with monoclonal antibodies specific for antigens of Ia+ T-cells, as well as either their T-helper/inducer (TH/I) or T-suppressor/cytotoxic (TS/C) subsets. Compared to normal subjects, patients with hyperthyroid Graves' disease had a significantly (p less than 0.0001) higher percentage of activated (Ia+ Leu 4+) T-cells (7.8 +/- 1.9 versus 1.9 +/- 0.4), wherein their percentage of Ia+ Leu 3a+ (Ia+ TH/I) subset was significantly increased (p less than 0.001) and the percentage of Ia+ Leu 2a+ (Ia+ TS/C) subset decreased; patients with hypothyroid Hashimoto's thyroiditis also had a significant (p less than 0.001) increase in the percentage of Ia+ T-cells (4.3 +/- 0.6 versus 1.9 +/- 0.4), wherein their percentage of Ia+ TH/I was significantly reduced (p less than 0.001), while the percentage of the Ia+ TS/C subset was increased compared to normal. Following a return of thyroid status to euthyroidism, the percentage of Ia+ T-cells decreased in both Graves' and Hashimoto's thyroiditis patients, but remained significantly higher (p less than 0.001) than normal subjects, while the Ia+ TH/I and Ia+ TS/C subsets were no longer different.

CONCLUSIONS

(1) the feasibility of enumerating Ia+ T-cells and their subsets in autoimmune thyroid diseases using two-coloured dyes and dual laser flow microfluorometric analytical techniques has been demonstrated. (2) Percentage increases in Ia+ T-cells have been demonstrated in both hyperthyroid Graves' and hypothyroid Hashimoto's which, following restoration to euthyroidism, decreased but still remained significantly higher than normal. (3) Patients with hyperthyroid Graves' and hypothyroid Hashimoto's disease were demonstrated to have the opposite phenotypic changes within activated T-cell subsets, thereby indicating that their pathogenic mechanisms are different.