Thyroglobulin Autoantibodies Do Not Influence the Outcome of Patients With Differentiated Thyroid Carcinoma

Thyroglobulin (Tg) is a sensitive and specific marker for differentiated thyroid carcinoma (DTC). The presence of thyroglobulin autoantibodies (TgAb) can interfere with Tg measurement in commonly used immunoassays, often resulting in falsely low or undetectable Tg levels. However, data on the prognostic significance of TgAb or its potential utility as a surrogate marker for DTC are limited, leaving its role in the clinical management of DTC uncertain. The aim of this study was the evaluation of the prognostic significance of TgAb in a clinical cohort of patients with DTC.

We included n = 289 patients with DTC who presented to our clinic for radioiodine treatment. Clinical data and follow-up outcomes were retrospectively analysed. The TgAb status at initial treatment and during follow-up was assessed, and its association with disease remission, persistence or recurrence was evaluated.

Roughly 25% of DTC patients in our cohort showed positive TgAb post-surgery. There were no significant differences between TgAb-positive and TgAb-negative patients in histology, tumour size, metastasis, therapeutic regimen or risk stratification.

The presence of TgAb did not influence the outcome regarding overall and disease-free survival. Results implicate that the initial appearance of TgAb does not influence the outcome of patients with DTC. Patients with positive TgAb should be monitored closely during follow-up as Tg measurement is unreliable, while overtreatment should be avoided.