Objective:To analyze the relationship between tumor-associated immune cells and cytokines with papillary thyroid carcinoma (PTC) and explore the correlation between tumor-associated immune cells and the risk stratification of PTC recurrence.Methods:A total of 58 PTC patients diagnosed by surgical pathology from Aug. 2022 to Aug. 2023 in the General Surgery and Thyroid and Hernia Department of Tianjin Medical University General Hospital were selected. All patients underwent thyroidectomy combined with central or lateral cervical lymph node dissection. According to lymph node metastasis status, patients were divided into lymph node metastasis-negative (22 cases) and lymph node metastasis-positive groups (36 cases) based on post-operative pathological diagnosis. Flow cytometry was used to detect the levels of tumor-associated immune cells (T, B, NK cells) and cytokines (IL-10, IL-17, IL-35, IFN-γ) in T cells.Results:Compared to normal tissue located distant from the cancer, a significant increase in the proportion of NK cells was observed in cancerous tissue ( t=-2.11, P=0.032). Similarly, the proportion of CD8+ T cells was also significantly elevated ( t=-5.12, P=0.005). In lymph node tissue, the proportion of CD4+ T cells in LNM-positive tissue was significantly higher than in LNM-negative tissue ( t=-3.89, P=0.004), while the proportion of CD8+ T cells exhibited a significant decrease ( t=2.41, P=0.004). Additionally, the levels of IL-10 in cancerous tissue were significantly elevated ( t=-3.83, P=0.003), as were the levels of IL-17 ( t=-4.83, P=0.003). In lymph node tissues categorized by LNM status, although not statistically significant, the levels of IL-10 and IL-17 were generally higher in LNM-positive cases compared to LNM-negative cases. Among the 58 cases stratified by recurrence risk, 22 cases (37.9%) were classified as low-risk, while 36 cases (62.1%) were classified as intermediate-risk. The differences in the proportions of CD4+ T and CD8+ T cell subsets in the lymph nodes of PTC patients were statistically significant. Logistic regression analysis indicated that a higher proportion of CD4+ T cell subsets in the lymph nodes of PTC patients was associated with a higher recurrence risk stratification compared to those with a lower proportion ( OR=1.107, 95% CI: 1.001-1.224). Using the predicted probability as the test variable and "low and medium risk" as the state variable, a ROC curve was constructed, yielding an AUC of 0.790 with P=0.003, indicating a good predictive effect of the model on the dependent variable. Conclusions:Compared to normal tissues located distant from cancerous regions, cancer tissues exhibit a significantly elevated proportion of tumor-associated immune cells and cytokine levels, thereby creating an immunosuppressive tumor microenvironment. Additionally, patients with papillary thyroid carcinoma (PTC) who are classified as having a higher risk of recurrence demonstrate a greater proportion of CD4+ T cell subsets in their lymph nodes.

Objective:To analyze the relationship between tumor-associated immune cells and cytokines with papillary thyroid carcinoma (PTC) and explore the correlation between tumor-associated immune cells and the risk stratification of PTC recurrence.Methods:A total of 58 PTC patients diagnosed by surgical pathology from Aug. 2022 to Aug. 2023 in the General Surgery and Thyroid and Hernia Department of Tianjin Medical University General Hospital were selected. All patients underwent thyroidectomy combined with central or lateral cervical lymph node dissection. According to lymph node metastasis status, patients were divided into lymph node metastasis-negative (22 cases) and lymph node metastasis-positive groups (36 cases) based on post-operative pathological diagnosis. Flow cytometry was used to detect the levels of tumor-associated immune cells (T, B, NK cells) and cytokines (IL-10, IL-17, IL-35, IFN-γ) in T cells.Results:Compared to normal tissue located distant from the cancer, a significant increase in the proportion of NK cells was observed in cancerous tissue ( t=-2.11, P=0.032). Similarly, the proportion of CD8+ T cells was also significantly elevated ( t=-5.12, P=0.005). In lymph node tissue, the proportion of CD4+ T cells in LNM-positive tissue was significantly higher than in LNM-negative tissue ( t=-3.89, P=0.004), while the proportion of CD8+ T cells exhibited a significant decrease ( t=2.41, P=0.004). Additionally, the levels of IL-10 in cancerous tissue were significantly elevated ( t=-3.83, P=0.003), as were the levels of IL-17 ( t=-4.83, P=0.003). In lymph node tissues categorized by LNM status, although not statistically significant, the levels of IL-10 and IL-17 were generally higher in LNM-positive cases compared to LNM-negative cases. Among the 58 cases stratified by recurrence risk, 22 cases (37.9%) were classified as low-risk, while 36 cases (62.1%) were classified as intermediate-risk. The differences in the proportions of CD4+ T and CD8+ T cell subsets in the lymph nodes of PTC patients were statistically significant. Logistic regression analysis indicated that a higher proportion of CD4+ T cell subsets in the lymph nodes of PTC patients was associated with a higher recurrence risk stratification compared to those with a lower proportion ( OR=1.107, 95% CI: 1.001-1.224). Using the predicted probability as the test variable and "low and medium risk" as the state variable, a ROC curve was constructed, yielding an AUC of 0.790 with P=0.003, indicating a good predictive effect of the model on the dependent variable. Conclusions:Compared to normal tissues located distant from cancerous regions, cancer tissues exhibit a significantly elevated proportion of tumor-associated immune cells and cytokine levels, thereby creating an immunosuppressive tumor microenvironment. Additionally, patients with papillary thyroid carcinoma (PTC) who are classified as having a higher risk of recurrence demonstrate a greater proportion of CD4+ T cell subsets in their lymph nodes.