This issue of European Journal of Endocrinology contains two articles which have in common the study in humans of the involvement of TSH receptor antibodies (TSH-R-ab) and T cells in goitrous conditions such as Graves' disease and sporadic goitre.
Aust et al. (1) describe activated, i.e. HLA-DR+, T cells not only in Graves goitres but also—and in the same proportions–in goitrous conditions such as non-toxic multinodular goitre (NTG) and thyroid autonomy (TA). Forty per cent of these activated T cells show an intracellular staining for IFN-γ, whereas half of them co-express another activation marker, i.e. CD69. Both NTG and TA are generally regarded as conditions in which the immune system is not activated ("nonautoimmune"), and hence the presence of activated T cells—although clearly in lower numbers as compared to Graves goitres—was surprising to the authors. Because the activation marker CD69 has also been implicated in tolerance induction in the thymus,