Due to a high frequency of autoimmune diseases in patients with ESRF we observed for 4 years 8 patients treated with HD with high level of TPOAb and 8 patients without TPOAb. Aim of the study was to estimate the role of TPOAb as a prognostic factor of hypothyreosis. We observed in a 4-years follow-up significant increase of TSH (p<0.05) in patients with high TPOAb level. fT3 and fT4 did't change in this time. In the group without TPOAb we observed significant (p<0.01) decrease of fT3 probably due to the disturbances in T4 to T3 conversion. Our results don't permit us to draw a final conclusions but induce us to further observation of hypothyreosis development in patients with ESRF.