The Prevalence of Antithyroperoxidase (TPO-Ab) and Antithyroglobuline (Tg-Ab) Autoantibodies in Healthy Women and Female Patients with Hyperthyroidism, Hypothyroidism and Simple Goiter: A Comparative Study

Considering the higher prevalence of autoimmune thyroid disorders in iodine replete areas and implementation of an adequate and sustainable IDD control program in Iran, this study was performed to investigate and compare the prevalence of antithyroperoxidase (TPO-Ab) and antithyroglobuline (Tg-Ab) autoantibodies among a control group and patients with hypothyroidism, hyperthyroidism and simple goiter. Serum T4, T3, TSH, TPO-Ab and Tg-Ab were measured in 1019 females, 20-50 years old, with and without thyroid dysfunction (control group=130, hypothyroid=379, hyperthyroid=195, simple goiter=315). The results were analyzed using t-test, Chi-square and ANOVA statistical methods. In the control group, 67.7% were found to be negative for autoantibodies, as compared to 45.5%, 35.5%, and 17.4% of patients with simple goiter, hypothyroidism and hyperthyroidism, respectively (P= 0.000001). The difference observed in the prevalence of TPO-Ab among the 4 groups was significant (P=0.00001) and the highest prevalence was observed in hyperthyroid cases. The difference in the prevalence of TgAb and both TgAb and TPOAb between the 4 groups was not significant (P>0.05), but the means of TPOAb and TgAb in these groups differed significantly (P=0.00001). In patients with simple goiter and hypothyroidism, the prevalence of autoantibodies increased with age (P<0.0001). The higher prevalence of TPO-Ab among patients with thyroid dysfunction confirms the pathogenic role of TPO-Ab in autoimmune and non-autoimmune thyroid disorders, although the role of Tg-Ab cannot be ignored.