[The prevalence of antithyroid antibodies and long term follow-up in patients with lipiodol iodine-induced goiter].

We have carried out a follow-up study on iodine-induced goiter to clarify whether or not iodine could be a factor in the progression as well as the promotion of thyroid autoimmunity. We selected 143 women of child-bearing age without any previous thyroid disorders who had received hysterosalpingography (H.S.G.). 45 Sex and age-matched healthy subjects were chosen as controls. Serum nonhormonal iodine (S.N.I.) levels, frequency of goiter and antimicrosomal antibody (MCHA) in all the Lipiodol-cases were significantly higher than those in the controls (p < 0.001, < 0.01 and < 0.01), respectively. When the subjects were divided into 9 groups according to the duration of each 5 months after H.S.G., serum TSH and S.N.I. levels, incidence of goiter and MCHA in the initial group were significantly higher than those in the other groups (p < 0.05). The S.N.I. levels became normalized in 30 months after H.S.G. and the goiters disappeared in almost the same duration, while the incidence of higher MCHA titers declined gradually but significantly around 40 months after H.S.G. compared with that in the first 5 months after H.S.G. (p < 0.05). The frequency of goiter and MCHA in 44 cases after a 6-39 month follow-up decreased significantly compared to that in the initial group (p < 0.05). Therefore, we tried an individual longitudinal follow-up study on MCHA titer in 12 cases for 35-103 months, resulting in a significant reduction or negativeness of the titer in 6 cases. Likewise, MCHA titers in all cases decreased significantly (p < 0.05) on later evaluation. The present data suggest that iodine in Lipiodol administered via the vagina will act not only as the promoting factor, but as an aggravating agent for thyroid autoimmunity.