TPO and hypothyroidism: In the prediction of the natural course of SH, Radetti et al (10) reported that the initial presence of goiter and elevated TG-Abs and the progressive increase in TPO-Abs and TSH value may be predictive of progression toward overt hypothyroidism for the group as a whole, and Lazar et al (14) reported that an initial TSH higher than 7.5 mIU/L and female gender are predictive factors for a sustained highly elevated TSH.