Changes of serum and urine β2-microglobulin of leukopenia in hyperthyroidism of Graves＇ disease before and after ^131I therapy

Objective To investigate the value of ^131Ⅰ therapy and the changes of the serum, urine contents of β2-microglobulin（ β2-MG）in leukopenia in patients with Graves＇ disease before and after ^131Ⅰ therapy. Methods Serum and urine β2-MG contents （with radioimmunoassay）, serum free triiodothyronine （FT3） and free tetraiodothyronine （FT4） lever （with chemiluminescence immunoassay） were determined before and after ^131Ⅰ therapy. At the same time, measure blood ured nitrogen （BUN） and creatine （Cr） Results The cure rate, improvement, invalid, hypothyroidiam and total effective rate of ^131Ⅰ therpy are 76.7%, 13.3%, 3.3%, 6.7%, 96.7% respectively. The serum and urine β2-MG contents as well as the serum FT3, FT4 levels in the 30 patients before treatment were significantly higher than those in the controls （P〈0.01）. While leucocyte was significantly lower than those in the control （P〈0.05）. After 3 months treatment, their FT3, FT4 levels lower than before treatment （P〈0.01）, [32-MG levels lower （vs before treatment, P〈0.05）, leucocyte increased （vs before treatments, P〈0.05）. After 6 months treatment, their β2- MG,FT3,FT4 levels dropped to approaching normal （vs controls, P〉0. 05 and vs before treatments, P〈0.01 ）. Both BUN and Cr of the controls and before treatment groups have no big difference. The serum FT3, FT4 level was positively correlative to the β2-MG （P〈0.05）. Conclusions ^131Ⅰ therapy is an ideal treatment for Graves＇ hyperthyroidism, which have many advantages. β2-MG could be used as a diagnostic indicator for leukopenia in patients with Graves＇ disease. Key words: Graves＇ disease;  Leucocyte;  Radiotherapy;  Thyroid hormones;  Iodine radioisotopes;  β2-microglobulin