The autoimmune infiltrate of Basedow's disease: analysis of clonal level and comparison with Hashimoto's thyroiditis.
The availability of high efficiency T-cell cloning techniques recently allowed the identification and characterization of clones derived from the thyroid infiltrate of patients with autoimmune thyroid diseases. Phenotypical and functional analysis of T-cell clones obtained from thyroid infiltrates of patients with Hashimoto's thyroiditis show that most of them are progenies of CD8+ cytolytic T cells with natural killer activity. This phenomenon, of potential importance in tissue damage, is markedly less pronounced in Basedow's disease glands. In both Hashimoto's thyroiditis and Basedow's disease only a minority of clones appear to be specific for autologous thyroid cells and most of them are potent interferon-gamma producers, while increased secretion of tumor necrosis factor-alpha is observed only in Hashimoto's thyroiditis. In contrast with normal lymphoid tissue, only very few T cell clones derived from both BD and HT infiltrates were able to produce detectable amounts of IL-4, suggesting that most of the thyroid-infiltrating T cells represent quite homogeneous populations of Th1-type "inflammatory" T cells. This peculiar potential of lymphokine secretion could play a role in the expression and/or maintenance of thyroid autoimmunity and thyroid functional damage.
University of Pisa, Italy.
S
S
Mariotti
G F
GF
del Prete
C
C
Mastromauro
M
M
de Carli
S
S
Romagnani
M
M
Ricci
A
A
Pinchera
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002999:Clone Cells; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D008222:Lymphokines / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013961:Thyroid Gland / Q000276:immunology*; D013967:Thyroiditis, Autoimmune / Q000276:immunology*
D008222:Lymphokines