Determination of serum levels of interferonª²¦Ã, interleukinª²4 and interleukinª²18 in patients with Graves¡¯ disease and relationship between them

    LI Yuª²Lin, TANG Xuª²Lei

    Department of Endocrinology, First Hospital, Lanzhou Medical College, Lanzhou 730000, China

    ¡¾Abstract¡¿ AIM: To investigate the relationship between serum interferonª²¦Ã (IFNª²¦Ã), interleukinª²4 (ILª²4) and interleukinª²18 (ILª²18) levels, and the immunopathogenesis of Graves¡¯ disease (GD). METHODS: The serum levels of IFNª²¦Ã, ILª²4 and ILª²18 were respectively measured by Enzymeª²linked immunosorbent assays (ELISA) in three groups: 40 newly diagnosed but untreated patients, 38 cases from the above mentioned 40 patients, whose thyroid function normalized after orally taking methimazole and in 30 healthy individuals. RESULTS: The serum IFNª²¦Ã, ILª²4 and ILª²18 levels of the 40 newly diagnosed and untreated GD patients and 38 thyroid function normalized GD patients were significantly higher than those in healthy group (P<0.01). Compared with the levels of IFNª²¦Ã, ILª²4 and ILª²18 before antiª²thyroid drugs, the serum ILª²4 level obviously increased (P<0.01) and the serum ILª²18 level decreased (P<0.05), but no statistical difference (P>0.05) in the IFNª²¦Ã level was observed after orally taking methimazole. In comparison with the normal group, the ratios of serum IFNª²¦Ã/ILª²4 significantly increased in the newly diagnosed groups (P<0.01), but the ratios were significantly reduced after orally taking methimazole (P<0.01). The positive correlations between the levels of IFNª²¦Ã and ILª²18 in the serum of the newly diagnosed groups (r=0.677, P<0.05), between the levels of ILª²18 and TT3, TT4 after orally taking methimazole (r=0.601, 0.535, P<0.05), and the negative correlation between the levels of ILª²4 and TT3, TT4 after orally taking methimazole (r=-0.678, -0.626, P<0.05) were obtained by correlation analysis. CONCLUSION: IFNª²¦Ã, ILª²4 and ILª²18 may play some important roles in the immunopathogenesis of GD. At the onset, GD is predominated by Th1 cells and the immune reaction drifts towards Th2 cells after orally taking methimazole. ......