Coexistence of thyroglobulin antibodies and thyroid peroxidase antibodies correlates with elevated thyroid-stimulating hormone level and advanced tumor stage of papillary thyroid cancer.

The correlation between thyroglobulin antibodies (TgAb) or thyroid peroxidase antibodies (TPOAb) and papillary thyroid cancer (PTC) remains controversial. This histological study aimed to explore the correlation between thyroid autoantibodies (TAb), thyroid-stimulating hormone (TSH), and PTC in patients with thyroid nodules (TN). This was a retrospective study. 2,132 non-autoimmune thyroid diseases (AITD) patients who underwent thyroidectomy were subdivided into: TgAb or TPOAb single positive (TgAb+ or TPOAb+) TN group; TgAb and TPOAb double positive or negative (TAb+ or TAb-) TN group. PTC patients showed a higher rate of TAb+ TN (10.24 vs. 4.89 %; P = 0.000) and a higher TSH level (1.83 ± 0.07 vs. 1.39 ± 0.03 mIU/L; P = 0.000) than patients with benign nodules. TAb+ TN patients showed a higher TSH level and PTC frequency than those with TAb- TN (1.91 ± 0.17 vs. 1.47 ± 0.03 mIU/L; P = 0.011) (41.35 vs. 22.08 %; P = 0.000). In PTC, TAb+ TN patients showed a higher TSH level (2.57 ± 0.35 vs. 1.79 ± 0.07 mIU/L; P = 0.032), a greater frequency of lymph node metastasis (52.73 vs. 36.51 %, P = 0.026), and a lower micro-PTC frequency (16.36 vs. 39.51 %; P = 0.001) than TAb- TN patients. PTC was correlated with TgAb+ TN (OR = 1.921, CI 1.431-2.580; P = 0.000), TPOAb+ TN (OR = 1.945, CI 1.195-3.165; P = 0.007), TAb+ TN (OR = 2.393, CI 1.635-3.501; P = 0.000), and serum TSH >1.35 mIU/L (OR = 1.742, CI 1.089-2.786; P = 0.021). Serum positive TgAb or TPOAb is an independent predictor for PTC regardless of AITD. The coexistence of TgAb and TPOAb confers a greater risk for PTC than isolated positive TgAb or TPOAb, and is correlated with elevated TSH level and advanced PTC stage.