Autoantibodies to thyroid peroxidase

Note-. 268 school ohildren aged 8-15 years were screened for iodine deficiency in one region of the Czeoh Republic. Actual serum levels of free daidzein, genistein, thyrotropin (TSH), free thyroid hormones, autoantibodies to thyroid peroxidase (AbTPO) and thyroglobulin (AbTg), and ioduria, along with thyroid volume, were measured. S.E.M. shows standard error of the mean. 

Note 86 university students (54 females and 32 males) ate 2 g/body weight of unprocessed, boiled, natural soybeans for seven consecutive days. Actual serum levels of daidzein and genistein, TSH free thyroid hormones, and autoantibodies to thyroid peroxidase and thyroglobulin were measured before, at the end, and 7 days after controlled soy consumption. The table provides an extract from Pearson s correlation matrices. Data from significant correlations (p < 0.05) in at least one subgroup of subjects in at least one stage of the experiment. NS means not significant other symbols are the same as in the previous tables. Source Reproduced from HampI eta/. (2007). 

Thyroglobulin (Tg) is used as a tumour marker for thyroid cancer, and is nsed post-snrgically to monitor disease recurrence (Krahn and Dembinski, 2009). Bnme et al. (2005) describe POC assays for autoantibodies to thyroid peroxidase (TPO) and to thyroglobnlin. Both assays are based on the ability of autoantibodies in test samples (whole blood, plasma or sera) to inhibit the binding of monoclonal antibodies to TPO or to Tg. These assays require no special equipment and yield resnlts in lOmin. 

Burne, P., Mitchell, S., Smith, B.R., 2005. Point-of-care assays for autoantibodies to thyroid peroxidase and to thyroglobulin. Xh5Toid 15, 1005-1010. 

Beever K, Bradbury J, Phillips D, McLachlan SM, Pegg C, Goral A, et al. Highly sensitive assays of autoantibodies to fhyroglobulin and to thyroid peroxidase. Clin Chem 1989 35 1949-54. 

AITD have high concentrations of circulating thyroid autoantibodies (Arai et ai, 2000 Carle et aL, 2006 Feldt-Rasmussen, 1996), for the most part the disorder appears to be the consequence of tissue damage initiated by T lymphocytes (Weetman and McGregor, 1994). Measurement of autoantibodies against thyroid peroxidase (TPO-Ab) and thyroglobulin (Tg-Ab) has for many years been a major tool in the diagnosis of autoimmune thyroid diseases, such as Hashimotos thyroiditis, primary myxedema and postpartum thyroiditis (Feldt-Rasmussen et ai, 1991 Feldt-Rasmussen, 1996). 

In a prospective study, the overall incidence of biochemical thyroid disorders was 12% in 254 patients with chronic hepatitis C randomized to receive ribavirin plus high-dose interferon alfa (6 MU/day for 4 weeks then 9 MU/week for 22 weeks) or conventional treatment (9 MU/week for 26 weeks) (165). There was no difference in the incidence or the time to occurrence of thyroid disorders between the groups. Of the 30 affected patients, 11 (37%) had positive thyroid peroxidase autoantibodies (compared with 1% of patients without thjroid dysfunction), nine developed symptomatic thjroid dysfunction, and only three had to discontinue treatment. There was no correlation between the viral response and the occurrence of thyroid disorders, and only female sex and Asian origin were independent predictors of thyroid disorders. 

Hoyle NR, The development and performance of three new immunoassays for serum thyroglobulin and serum autoantibodies to thyroglobulin and thyroid peroxidase. Clin Chem 1993 39 1258A. 

TSH. Autoantibodies that react with orbital muscle and fibroblast tissue in the skin are responsible for the extrathyroidal manifestations of Graves disease, and these autoantibodies are encoded by the same germfine genes that encode for other autoantibodies for striated muscle and thyroid peroxidase. The defect leading to abnormal antibody production may be a genomic point mutation in the extracellular domain of the thyrotropin receptor. CfinicaUy, the extrathyroidal disorders may not appear at the same time that hyperthyroidism develops. 

Prentice LM, Phillips DIW, Sarsero D, Beever K, McLachlan SM, Smith B (1990) Geographical distribution of subclinical autoimmune thyroid disease in Britain a study using highly sensitive direct assays for autoantibodies to thyroglobulin and thyroid peroxidase. Acta Endocrinol, 123 493-498. 

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