目的：探究白细胞介素-35（IL-35）、免疫球蛋白4/免疫球蛋白（IgG4/IgG）、促甲状腺免疫球蛋白（TSI）水平与甲状腺相关性眼病（TAO）活动度及严重程度的相关性分析。方法：选取2023年1月至2024年7月本院收治的148例TAO患者为观察组，根据活动度分为活动组（75例）和非活动组（73例），根据病情严重程度分为重度组（95例）和轻度组（53例）；另选取同期148例体检健康患者为对照组。比较血清中IL-35、IgG4/IgG、TSI的水平；采用Pearson法分析血清IL-35、IgG4/IgG、TSI水平与活动度及严重程度的相关性；多因素Logistic回归分析TAO患者发展为重度的影响因素；ROC曲线分析血清IL-35、IgG4/IgG、TSI水平对TAO患者发展为重度的诊断价值。结果：与对照组相比，观察组血清IL-35水平明显降低（P<0.05），IgG4/IgG、TSI水平明显升高（P<0.05）；与非活动组组相比，活动组血清IL-35水平明显降低（P<0.05），IgG4/IgG、TSI水平明显升高（P<0.05）；与轻度组相比，重度组血清IL-35水平明显降低（P<0.05），病程、IgG4/IgG、TSI水平明显升高（P<0.05）；血清IL-35水平与活动度及严重程度呈负相关，IgG4/IgG水平与活动度及严重程度呈正相关，TSI水平与活动度及严重程度呈正相关（P<0.05）；多因素Logistic回归分析结果显示，IL-35、IgG4/IgG、TSI均为TAO患者发展为重度的影响因素（P<0.05）；血清IL-35、IgG4/IgG、TSI水平诊断TAO患者发展为重度的曲线下面积（AUC）分别为0.868、0.859、0.830，三者联合诊断的AUC为0.955，明显高于各单一指标诊断（Z三者联合-IL-35=2.893、Z三者联合-IL-35=3.510、Z三者联合-IL-35=4.157，P=0.004、0.000、0.000）。结论：TAO患者血清IL-35水平明显下调，IgG4/IgG、TSI水平明显上调，且IL-35、IgG4/IgG、TSI水平与TAO活动性及严重程度相关，三者联合对TAO患者发展为重度具有较高的诊断价值。

Objective: To investigate the correlation between the levels of interleukin-35 (IL-35), immunoglobulin 4/immunoglobulin (IgG4/IgG), thyroid stimulating immunoglobulin (TSI) and the activity and severity of thyroid associated ophthalmopathy (TAO). Methods: A total of 148 TAO patients admitted to our hospital from January 2023 to July 2024 were regarded as the observation group. They were assigned into an active group (75 cases) and a inactive group (73 cases) based on their activity level, and were assigned into a severe group (95 cases) and a mild group (53 cases) based on the severity of their condition; another 148 healthy patients who underwent physical examinations were regarded as the control group. The levels of IL-35, IgG4/IgG, and TSI in serum were compared. Pearson method was applied to analyze the correlation between serum IL-35, IgG4/IgG, TSI levels and activity and severity. Multivariate logistic regression was applied to analyze the influencing factors of TAO patients developing severe symptoms. ROC curve was applied to analyze the diagnostic value of serum IL-35, IgG4/IgG, and TSI levels for the development of severe TAO in patients. Results: Compared with the control group, the serum IL-35 level in the observation group was obviously lower (P<0.05), and the IgG4/IgG and TSI levels were obviously higher (P<0.05). Compared with the inactive group, the serum IL-35 level in the active group was obviously lower (P<0.05), and the IgG4/IgG and TSI levels were obviously higher (P<0.05). Compared with the mild group, the serum IL-35 level in the severe group was obviously lower (P<0.05), and the disease duration, IgG4/IgG, and TSI levels were obviously higher (P<0.05). The serum IL-35 level was negatively correlated with activity and severity, IgG4/IgG level was positively correlated with activity and severity, and TSI level was positively correlated with activity and severity (P<0.05). Multiple logistic regression analysis showed that IL-35, IgG4/IgG, and TSI were all influencing factors for TAO developing into severe (P<0.05). The areas under the curve (AUC) for diagnosing severe TAO with serum IL-35, IgG4/IgG, and TSI levels were 0.868, 0.859, and 0.830, respectively. The AUC of the combined diagnosis of the three factors was 0.955, which was obviously higher than that of each single indicator diagnosis (Z three factors combination - IL-35=2.893, Z three factors combination - IL-35=3.510, Z three factors combination - IL-35=4.157, P=0.004, 0.000, 0.000). Conclusion: Serum IL-35 level is obviously downregulated in TAO patients, while IgG4/IgG and TSI levels are obviously upregulated.The levels of IL-35, IgG4/IgG, and TSI are correlated with the activity and severity of TAO, and their combination has high diagnostic value for TAO developing into severe.