Comparison of Thyroid Gland Sonography Index with Serum Antithyroid Peroxidase, Antithyroglobulin, and Thyroid Function Tests in Patients with Hashimoto Thyroiditis.

Background: Ultrasound examination of the thyroid has emerged as a useful diagnostic and prognostic tool, along with measuring serum titers of anti-thyroid peroxidase (TPO), anti-thyroglobulin (Tg), and thyroid hormones, in patients with Hashimoto's thyroiditis. So, we aimed at considering correlations of ultrasonographic, antibodies, and thyroid hormone levels.

Materials and methods: A total of 149 patients (118 females, 31 males; aged 18-60 years; mean age: 38.60 ± 8.03 years) who were diagnosed with Hashimoto's thyroiditis were enrolled in the study. The blood sample was taken to measure serum titers of free T3 (FT3) and T4 (FT4), TSH, anti-TPO, and anti-Tg antibody titers. The thyroid sonography of each patient was classified into one of the five grades by real-time ultrasound (US) based on echogenicity, thyroid size, and thyroid pattern. We evaluated whether there was a correlation between thyroid characteristics observed via ultrasound and serum levels of thyroid hormones, anti-TPO antibodies, and anti-Tg antibodies.

Results: Nodular structures were detected in 54 (36.2%) patients (38 micro-nodular and 16 macro-nodular). Echogenicity was recorded as isoechoic in 15(10.07%) and hypoechoic in 119 (79.87%) subjects. Euthyroid subjects had significantly thicker isthmus than overt and subclinical hypothyroid patients (P=0.018). Mean serum TSH, anti-Tg, and anti-TPO antibody titers showed a significant increase in patients with macro-nodules compared to those with micro-nodules and individuals without nodules (P0.05). The thickness of the isthmus had a significant negative correlation with FT4 (P=0.046; r=0.11) and FT3 (P=0.017; r=0.15), respectively. Thyroid autoantibodies had positive significant correlations with different parameters of thyroid volume (P0.05).

Conclusions: Thyroid US findings, in addition to serum anti-Tg and anti-TPO antibody titers, might be correlated with the severity and extent of Hashimoto's thyroiditis, but further evaluations are needed.