, it was found that the thyroid gland had the maximum amount of selenium per gram of tissue . autoimmune thyroiditis ( ait ) , the prototype of autoimmune diseases , is characterized by t - cell - mediated autoimmune destruction of thyroid cells . environmental factors , such as iodide intake , immunotherapeutic agents , or viral infections that may initiate the disease . in areas , where selenium deficiency is prevalent , higher incidence of thyroiditis has been reported due to a decreased activity of selenium - dependent glutathione peroxidase enzyme within thyroid cells . severe nutritional selenium deficiency leads to an increased rate of thyroid cell necrosis and invasion of macrophages . whether this it may be assumed , however , that thyroid cell damage may initiate or maintain autoimmune thyroiditis , especially in patients susceptible to the development of autoimmune diseases . to study the effect of selenium supplementation in patients with autoimmune thyroid disease . patients of all age groups and both sexes with autoimmune thyroid disease ( as defined by an anti- thyroid peroxidase antibody [ tpoab ] level more than 150 iu / ml ) irrespective of the baseline thyroid status . patients with overt hyperthyroidism who are on antithyroid drugs , patients on any other medication , which may alter the immunity status of the patients , and pregnant patients were excluded from the study . patients were randomized into two age and tpoab - matched groups ; 30 patients received 200 g sodium selenite / day , orally , for 3 months , and 30 patients received placebo . the differences in antibody concentrations at the beginning and end of the study were determined by t - test for paired samples . patients of all age groups and both sexes with autoimmune thyroid disease ( as defined by an anti- thyroid peroxidase antibody [ tpoab ] level more than 150 iu / ml ) irrespective of the baseline thyroid status . patients with overt hyperthyroidism who are on antithyroid drugs , patients on any other medication , which may alter the immunity status of the patients , and pregnant patients were excluded from the study . patients were randomized into two age and tpoab - matched groups ; 30 patients received 200 g sodium selenite / day , orally , for 3 months , and 30 patients received placebo . the differences in antibody concentrations at the beginning and end of the study were determined by t - test for paired samples . in the selenium treated group 27 patients were female , and three patients were male ( m : f = 1:9 ) , which was comparable with the ratio in the placebo - treated group ( 1:7.3 ) the mean ages at presentation in both the groups were 34  2.5 and 31  3.4 years , respectively . at study entry , the mean tpoab concentrations were identical for both groups ( selenium treated group , 669  205 iu / ml ; placebo , 729  277 iu / ml ) . out of the total 30 patients in the selenium treated group , 6 patients were overtly hypothyroid , 15 were subclinical hypothyroid , 6 were euthyroid , and 3 were subclinical hyperthyroid . there were comparable numbers of patients in each subgroup in the placebo - treated group also . the mean tpoab concentration decreased significantly by 49.5% ( p < 0.013 ) in the selenium treated group versus 10.1% ( p < 0.95 ) in the placebo - treated group . in subgroup analysis , the decrease in the mean tpoab titre was highest in the subclinical hyperthyroid group ( up to 64.42% ) , and comparable in the other three groups ( 41.13% , 47.18% , and 42.64% in the euthyroid , hypothyroid , and subclinical hypothyroid groups respectively ) . one patient with hypothyroidism in the selenium treated group with a tpoab concentration of > 1000 iu / ml , had completely normalized antibody concentrations after 3 months . it was also found that those patients with tpoab greater than 1000 iu / ml revealed a mean 31.38% reduction in the selenium - treated patients , compared with no significant change in tpoab in the placebo group . . glutathione peroxidase can reduce hydrogen peroxides and phospholipid hydroperoxides , and hence can reduce the production of free radicals and reactive oxygen species . these mechanisms may contribute to reduced inflammatory activity in the organ - specific autoimmune response , and may explain the improvement of autoimmune thyroiditis in our study . based on the link described above between selenium and the thyroid , several studies applying organic and inorganic selenium compounds were undertaken in patients , with ait in areas with low to borderline - low - selenium content . a prospective placebo - controlled clinical study with selenium in ait conducted in the selenium deficient area of bavaria in southern germany , by grtner et al . in 2002 showed a 36% reduction in anti - tpo titers in the selenium - treated group , whereas a further reduction of up to 60% was seen in a subgroup of patients with basal anti - tpo levels above 1200 iu / ml . supplementation of selenium has a significant impact on inflammatory activity in thyroid - specific autoimmune disease . it would be of interest to determine whether early treatment with selenium in patients with newly developed autoimmune thyroiditis may delay , or even prevent the natural course of these diseases .
introduction : in areas with severe selenium deficiency higher incidence of thyroiditis has been reported due to a decreased activity of selenium - dependent glutathione peroxidase enzyme within thyroid cells.aims and objective : to study the effect of selenium supplementation in patients with autoimmune thyroid disease.materials and methods : this is a blinded placebo - controlled prospective study done in 60 patients with autoimmune thyroid disease ( as defined by an anti - thyroid peroxidase antibody ( tpoab ) level more than 150 iu / ml ) irrespective of the baseline thyroid status . 
 patients with overt hyperthyroidism who are on antithyroid drugs , patients on any other medication , which may alter the immunity status of the patients , and pregnant patients were excluded from the study . 
 patients were randomized into two age and tpoab - matched groups ; 30 patients received 200 g of sodium selenite / day , orally , for 3 months , and 30 patients received placebo . 
 all hypothyroid patients were given l - thyroxine replacement.results:of 30 patients in the selenium treated group , 6 patients were overtly hypothyroid , 15 were subclinical hypothyroid , 6 were euthyroid , and 3 were subclinical hyperthyroid . 
 the mean tpoab concentration decreased significantly by 49.5% ( p < 0.013 ) in the selenium treated group versus 10.1% ( p < 0.95 ) in the placebo - treated group.conclusion:selenium substitution has a significant impact on inflammatory activity in thyroid - specific autoimmune disease . 
 it would be of interest to determine whether early treatment with selenium in patients with newly developed autoimmune thyroiditis may delay or even prevent the natural course of these diseases .