Kh. Allaisaikhan¹, B Gerel'¹, M. Sohmiya² and Y. Kato²

¹Third Department of Internal Medicine, School of Medicine, Health Sciences University of Mongolia

²First Department of Internal Medicine, Shimane Medical University, humo, Japan

In forty-three thyrotoxic patients a retrospective study was undertaken to investigate the relationship between various parameters and the remission of the Graves disease. TRH test was used an indicator of antithyroid drug treatment outcome. Various other parameters including clinical characteristics, serum thyroid hormones, TSH, thyroid autoantibodies and TSH receptor antibody titers were also determined. One and half years of the therapy most patients became clinical and biochemical euthyroid and had both of plasma total T3 and TSH normal response to the TRH test. We could not observe any significant differences on age, sex, age of onset and duration of the treatment, between the remission (A) and relapsed (B) groups. Twelve (27.9%) of 43 patients relapsed with in year and 31 (72.1) patients remained in remission more than one year. Both of "TSH and "T3 increments were significantly greater in a group A than group B (P < 0.01 for "TSH, P < 0.01 for T3 respectively). Among above biochemical parameters, only plasma total T3 was significantly distinguished between those two group patients at one month beforeTRH loading test. It was 106.1±15.5 ng/dl for group A, 124.3±15.3 ng/dl for group B, (P value < 0,001). Also the basal levels of plasma T3 were significantly lower in remission group (106.7 ± 17.0 ng/= dl in a group A, 122.8 ± 21.7 ng/dl for group B, P value was 0.01). Other three female patients those did not include in this study still had absence of either T3 or TSH response to TRH test, even after long-term antithyroid drug treatment (range 18-36 months). In those patients' thyroglobulin binding inhibiting immunoglobulin (TB II) concentrations were significantly higher than either A or B group at one month before TRH test (range 20-45%). These findings similar to our (10) and others previous studies (8-13). It is concluded that plasma total T3 and TBII concentration are most useful practical indicator to evaluate the effect of the antithyroid drug treatment and both of plasma total T3 and TSH response to TRH test modulate by plasma total T3 concentration.