ESPE Abstracts

Background: Chronic autoimmune thyroiditis (cAIT) leads to hypothyroidism due to T cell-mediated cytotoxicity in most cases. By contrast, Graves’ disease (GD) with thyrotropin receptor stimulatory autoantibodies cause hyperthyroidism. OPG a cytokine receptor which mediates suppressive effect on osteoclastogenesis is a key regulator of inflammation and may be a link between bone, autoimmune disease and vasculature.

Objective and hypotheses: Cytokines OPG and IL-1β play a crucial role in modulating immune response in these two opposite clinical and hormonal thyroid diseases.

Method: The study group consisted of 64 children: 44 newly diagnosed, untreated children with cAIT (n=22), GD (n=22) and 20 healthy children. Cytokine concentrations were evaluated using ELISA.

Results: We observed significantly higher concentrations of OPG in children with GD (P<0.01) (mean±S.D.; 4.48±2.01 pmol/l) compared to control (3.02±1.17 pmol/l); whereas no significant difference between children with cAIT (3.79±1.28 pmol/l) vs control (P>0.05) and cAIT vs GD (P>0.05) was observed. IL-1β concentration were significantly higher in children with cAIT (median 2.16 pg/ml, IQR 0.87) compared to control (median 1.88 pg/ml, IQR 1.04, P<0.05) and GD (median 1.39 pg/ml, IQR 1.27, P<0.01). In children with hypothyroidism IL-1β correlated positively with OPG (r=0.44; P<0.05). ROC curve indicates good efficacy of OPG to discriminate hyperthyroid and healthy children (AUC=0.716; P=0.017) at cut-off point of 4.54 pmol/l with low sensitivity 54.5% but high specificity 95%. In contrast IL-1β may be a marker of hypothyroidism and effectively differentiates the group of hypothyroid children from GD children (AUC=0.773; P=0.002) with good sensitivity 72.7% and high specificity 86.4% as well as the group of healthy children with cAIT children (AUC=0.77; P=0.003) with sensitivity of 59.1% and high specificity 95%.

Conclusion: We suggest, that OPG may be considered as a marker of hyperthyroidism (GD) and IL-1β as marker of hypothyroidism (cAIT) in children with autoimmune thyroid disease.