[Comparison of diagnostic performance of thyroid autoantibodies and high-resolution ultrasound in euthyroid...

Objective: To compare the diagnostic performance of thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb) and high-resolution ultrasound (HRUS) in euthyroid Hashimoto's thyroiditis (HT). Methods: From January 2016 to January 2019, patients with complete data of preoperative thyroid function, TPOAb, TgAb and HRUS who had undergone thyroid surgery treatment at the First Affiliated Hospital with Nanjing Medical University were reviewed. The diagnostic value of different diagnostic methods was compared using histopathology (HP) examination result as the gold standard. Results: The data of 792 patients (217 males and 575 females) was retrospectively collected. The M(Q₁,Q₃)of patients' age was 41(32,52)years and the range was 16-75 years. With HP as the diagnostic gold standard, TPOAb exhibited similar sensitivity (59.3% vs 61.2%, P=0.752), accuracy (85.0% vs 83.6%, P=0.379), area under the receiver operating characteristic curve (AUC) (0.767 vs 0.764, P=0.886) and higher specificity (94.2% vs 91.6%, P=0.033) when compared with TgAb in diagnosing euthyroid HT. They both exhibited a higher sensitivity (59.3% vs 44.5%, P = 0.002; 61.2% vs 44.5%, P<0.001), accuracy (85.0% vs 79.7%, P = 0.001; 83.6% vs 79.7%, P = 0.013) and AUC (0.767 vs 0.684, P<0.001; 0.764 vs 0.684, P<0.001) than HRUS. Compared with each method alone, the sensitivity and AUC of TPOAb combined with TgAb or HRUS were improved. The combination of three methods showed the greatest sensitivity. Concordance analysis demonstrated that TPOAb and HP had a moderate agreement (Kappa=0.580, 95%CI:0.513-0.647,P<0.001). Conclusions: The combination of thyroid antibodies, TPOAb and TgAb, can improve sensitivity, accuracy and AUC of diagnosis in euthyroid Hashimoto's thyroiditis. The two antibodies combined with HRUS exhibited the highest diagnostic performance. Elevated TPOAb showed moderate diagnostic consistency with histopathologic evidence of HT.