Assesment of oxidative status and its association with thyroid autoantibodies in patients with euthyroid autoimmune thyroiditis

Abstract

Oxidative stress results from either overproduction of free radicals or insufficiency of several anti-oxidant defense systems. It leads to oxidation of main cellular macromolecules and a resultant molecular dysfunction. Thyroid hormones regulate oxidative metabolism and, thus, play a role in free radical production. Studies evaluating oxidative stress in patients with hypothyroidism and hyperthyroidism have been encountered in recent years; however, oxidative status in patients with euthyroid autoimmune thyroiditis (AIT) was not investigated previously. Thirty-five subjects with euthyroid AIT and 35 healthy controls were enrolled in the study. Serum oxidative status was determined by the measurement of total anti-oxidant status (TAS), total oxidant status (TOS), ischemia-modified albumin (IMA), and oxidized-low density lipoprotein (ox-LDL) levels. Serum TAS levels were significantly lower (p<0.001), while serum TOS levels and IMA levels were significantly higher (p<0.001 and p=0.020, respectively) in patients compared to controls. In both groups, ox-LDL levels were similar (p=0.608). Serum TAS levels were negatively correlated with anti-thyroid peroxidase and anti-thyroglobulin (anti-TG) levels (rho=-0.415, p=0.001 and rho=-0.484, p<0.001, respectively). Serum TOS was positively correlated with anti-TG levels (rho=0.547, p<0.001). Further, TAS was positively correlated with free T4 levels (r=0.279, p=0.043). No correlation was observed between thyrotropin, free T3 levels, and TOS and TAS levels. These results suggest that oxidants are increased, and anti-oxidants are decreased in patients with euthyroid AIT, and oxidative/anti-oxidative balance is shifted to the oxidative side. Increased oxidative stress might have a role in thyroid autoimmunity.

Evaluation of Serum S100A8/S100A9 Levels in Patients with Autoimmune Thyroid Diseases

“…However, Baser et al have reported TAS levels were lower and TOS levels were higher in euthyroid AITD cases, compared to those in healthy subjects. In addition, they found that there was a negative correlation between serum TAS levels and anti-tpo and anti-tg, a negative correlation between TOS levels and anti-tg (21). The oxidant markers evaluated in this study included TOS, OSI, LOOH, and the antioxidant markers included -SH and TAS.…”

The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis

“…Thyroid autoantibodies being correlated negatively with antioxidant molecules may suggest that HT may be related to oxidative stress. When studies investigating the relationship between oxidative stress parameters and thyroid autoantibodies were evaluated, a negative correlation was present between the TAS level and anti-TG and anti-TPO, while a positive correlation was present between TOS and anti-TG in the study by Baser et al (20). Nanda et al found a positive correlation of the oxidant molecules malondialdehyde and protein carbonyl with anti-TPO (36).…”

“…Baser et al (20) reported lower TAS and higher TOS levels in euthyroid HT patients compared to healthy controls. In the study by Wang et al (21) performed to determine the level of oxidative stress in patients with thyroid cancer, Graves' disease, HT and a control group, the TAS level was found to be lower, while TOS and OSI were found to be higher in the hypothyroid group than in the healthy control group.…”

The impact of levothyroxine sodium treatment on oxidative stress in Hashimoto’s thyroiditis

“…LDLcholesterol was calculated by the method by Friedewald et al (13). TSH, fT 4 , anti-TPO (normal range: 0-34 IU/mL), and anti-TG (normal range: 0-115 IU/mL) levels were measured by electroluminescence immunoassay method in Cobas E601 (Roche Diagnostics) analyzer.…”

“…In the pretreatment patients with HT, the correlation analysis between oxidative stress parameters and other laboratory parameters is shown in Table 3 In stepwise multivariable linear regression analysis, fT 4 and anti-TPO levels were found to be independent predictors of the OSI, TAS, TOS, total thiol, PON1, and arylesterase before the treatment. In stepwise multivariable logistic regression analysis, TSH, anti-TPO, OSI, and arylesterase levels were found to be independent predictors of hypothyroidism (Table 4).…”