Abstract
The apoptosis of lymphocytes, which occurs in autoimmune diseases, is usually induced by the Fas/Fas ligand system. As the assay of nucleosomes produced by apoptotic cells can be used to quantitate apoptosis, we evaluated nucleosome and soluble Fas ligand (sFasL) levels of cultured mononuclear cells to clarify the apoptosis of mononuclear cells in patients with autoimmune thyroid diseases by enzyme-linked immunosorbent assay. Nucleosome levels of cultured mononuclear cells in patients with untreated Graves' disease were significantly higher (3.27±2.90 U/ml) than those of control subjects (1.39±0.24 U/ml) and euthyroid patients with treated Graves' disease (1.53±0.33 U/ml). Nucleosome levels of cultured mononuclear cells were positively correlated with sFasL levels (r=0.544, p<0.01). It is therefore likely that increased sFasL levels elicit apoptosis of these cells in untreated Graves' disease.