Yongping Liu, Shuo Wang, Qingling Guo, Yongze Li, Jing Qin, Na Zhao, Yushu Li, Zhongyan Shan, and Weiping Teng
Hashimoto’s thyroiditis (HT) is characterized by elevated specific auto-antibodies, including TgAb and TPOAb. Increasing evidence has demonstrated the essential role of Th17 cells in HT. However, the underlying mechanism is still unclear. Semaphorin 5A (Sema 5A) is involved in several autoimmune diseases through the regulation of immune cells. The aim of the present study was to explore the role of Sema 5A in HT.
We measured serum Sema 5A levels in HT (n = 92) and healthy controls (n = 111) by enzyme-linked immunosorbent assay (ELISA). RNA levels of Sema 5A and their receptors (plexin-A1 and plexin-B3), as well as several cytokines (IFN-γ, IL-4 and IL-17), were detected by real-time polymerase chain reaction in peripheral blood mononuclear cells from 23 patients with HT and 31 controls. In addition, we investigated the relationship between serum Sema 5A and HT.
Serum Sema 5A in HT increased significantly compared with healthy controls (P < 0.001). Moreover, serum Sema 5A levels were positively correlated with TgAb (r = 0.511, P < 0.001), TPOAb (r = 0.423, P < 0.001), TSH (r = 0.349, P < 0.001) and IL-17 mRNA expression (r = 0.442, P < 0.001). Increased Sema 5A RNA expression was observed (P = 0.041) in HT compared with controls. In receiver-operating characteristic (ROC) analysis, serum Sema 5A predicted HT with a sensitivity of 79.35% and specificity of 96.40%, and the area under the curve of the ROC curve was 0.836 (95% CI: 0.778–0.884, P < 0.001).
These data demonstrated elevated serum Sema 5A in HT patients for the first time. Serum Sema 5A levels were correlated with thyroid auto-antibodies and IL-17 mRNA expression. Sema 5A may be involved in immune response of HT patients.
Yun Hu, Na Li, Peng Jiang, Liang Cheng, Bo Ding, Xiao-Mei Liu, Ke He, Yun-Qing Zhu, Bing-li Liu, Xin Cao, Hong Zhou, and Xiao-Ming Mao
Thyroid nodules are usually accompanied by elevated thyroglobulin (Tg) level and autoimmune thyroid diseases (AITDs). However, the relationship between Tg and AITDs is not fully understood. Dysfunction of regulatory T cells (Tregs) plays an important role in the development of AITDs. We aimed to evaluate the effects of Tg on the function of Tregs in patients with thyroid nodules.
Tg levels and the functions of Tregs in peripheral blood and thyroid tissues of patients with thyroid nodules from Nanjing First Hospital were evaluated. The effects of Tg on the function of Tregs from healthy donors were also assessed in vitro. The function of Tregs was defined as an inhibitory effect of Tregs on the effector T cell (CD4+ CD25− T cell) proliferation rate.
The level of Tg in peripheral blood correlated negatively with the inhibitory function of Tregs (R = 0.398, P = 0.03), and Tregs function declined significantly in the high Tg group (Tg >77 μg/L) compared with the normal Tg group (11.4 ± 3.9% vs 27.5 ± 3.5%, P < 0.05). Compared with peripheral blood, the function of Tregs in thyroid declined significantly (P < 0.01), but the proportion of FOXP3+ Tregs in thyroid increased (P < 0.01). High concentration of Tg (100 μg/mL) inhibited the function of Tregs and downregulated FOXP3, TGF-β and IL-10 mRNA expression in Tregs in vitro.
Elevated Tg level could impair the function of Tregs, which might increase the risk of AITDs in patient with thyroid nodules.