Objective: To deepen understanding of IgG4-related diseases (RDs), we analyzed the associated lymphocyte subtypes, and explored the pathogenesis and potential immunotherapeutic targets. Methods: Eighty-six patients with IgG4-RDs were enrolled, and their clinical characteristics, peripheral lymphocyte subtypes, and disease course were analyzed. Results: The mean age of the participants was 36-87(62±11) years; 51 were male (59.3%) and 35 were women (40.7%); and 34.9% had a history of allergy. Follow-up lasted 4.8 (0.4, 14.1) months. The most common symptoms were abdominal pain, and submandibular gland and lacrimal gland swelling (each 20.9%). Sixty-five (75.6%) participants had multiple organ involvement, and the most frequently affected organs were the pancreas (52.3%), submandibular gland (51.2%), and lacrimal gland (34.9%). A high eosinophil count; high IgE, IgG, IgG1, and IgG4 concentrations; and low complement C3 and C4 concentrations were present in 18.8% (16/85), 30.0% (24/80), 72.9% (62/85), 58.3% (28/48), 89.5% (77/86), 61.2% (52/85), and 50.0% (42/84), respectively, of the participants. In addition, 64.7% (55/85) were positive for autoantibodies, and the most frequent was anti-nuclear antibody (63.5%). The proportion of CD4+T lymphocytes increased in 25.7% (9/35) of the participants, which was accompanied by an increase in the ratio of CD4+/CD8+T lymphocytes (22.9%, 8/35). Importantly, most participants (90.0%, 18/20) had a high proportion of regulatory T (Treg) cells. High interleukin (IL)-2, IL-6, and IL-10 concentrations were present in 50.0% (11/22), 33.3% (10/30), and 16.7% (5/30), respectively, of the participants. Substantial lymphoplasmacytic infiltration, fibrosis, IgG4-positive plasma cell infiltration, and lymphoid follicle hyperplasia or ectopic formation were present in 79.2% (42/53), 67.9%(36/53), 35.8%(19/53) and 30.2% (16/53), respectively, of the participants. Fifty-three participants with detailed pathologic data were also further evaluated, of whom 24.5% (13/53), 3.8% (2/53), and 67.9% (36/53) had definite, probable, and possible diagnoses; and 3.8% (2/53) could not be diagnosed. Compared with baseline, the percentage of eosinophils and the IgE, IgG, and IgG4 concentrations decreased significantly; and the complement C3 and C4 concentrations had increased significantly after 6 months of treatment (all P<0.05). The IgG4 concentration after 6 months of treatment negatively correlated with that of C4, and positively correlated with the baseline concentration of IgE and the IgG4/IgG ratio. Conclusion: IgG4-RDs are a group of diseases characterized by male predisposition; multiple organ involvement; a high eosinophil count; high IgE, IgG, IgG1, and IgG4 concentrations; and a low C3 concentration. Peripheral CD4+T cells and Treg cells are also more abundant. The diseases can be controlled with glucocorticoids and immunosuppressive drugs in the majority of instances. The IgG4 concentration after 6 months of treatment negatively correlates with the baseline complement C4 concentration and positively correlates with the IgE concentration and IgG4/IgG ratio, which suggests that IgG4/IgG, IgE, and complement should be closely monitored to evaluate disease activity and the efficacy of treatment in such patients.
目的： 探讨IgG4相关性疾病（IgG4-RD）患者的临床特征，分析淋巴细胞亚型以及潜在的发病机制及免疫治疗靶点。 方法： 横断面研究。回顾性收集2018年1月至2022年2月在天津医科大学总医院就诊的IgG4-RD患者86例。分析患者的人口学资料、症状和体征、器官受累情况、实验室指标、淋巴细胞亚型、组织病理学表现及治疗情况。 结果： 86例IgG4-RD患者的平均发病年龄为36~87（62±11）岁，其中男性51例（59.3%），女性35例（40.7%），34.9%的患者有过敏史，随访时间为4.8（0.4，14.1）个月。最常见的症状体征为腹痛、颌下腺肿大、泪腺肿大（各占20.9%）。75.6%的患者受累器官超过1个，最常见的受累器官为胰腺（52.3%）、颌下腺（51.2%）和泪腺（34.9%）。18.8%（16/85）伴随嗜酸性粒细胞比例升高，30.0%（24/80）IgE升高，61.2%（52/85）补体C3减低，50.0%（42/84）补体C4减低，72.9%（62/85）IgG升高，58.3%（28/48）IgG1 升高，89.5%（77/86）IgG4升高。64.7%（55/85）存在自身抗体阳性，最常见的阳性自身抗体是抗核抗体（ANA）（63.5%）。25.7%（9/35）CD4+T淋巴细胞比例升高，22.9%（8/35）CD4+/CD8+T淋巴细胞比值升高，90.0%（18/20）调节性T细胞（Treg）比例升高。50.0%（11/22）IL-2升高，33.3%（10/30）IL-6升高，16.7%（5/30）IL-10升高。79.2%（42/53）存在大量淋巴浆细胞浸润，67.9%（36/53）存在纤维化，35.8%（19/53）IgG4阳性/IgG阳性浆细胞>40%，且每高倍镜视野IgG4阳性浆细胞>10个，30.2%（16/53）淋巴滤泡增生或异位形成。应用2011年日本研究小组提出的标准对53例具有详尽病理资料的患者进行评价，24.5%（13/53）可确定诊断，3.8%（2/53）很可能诊断，67.9%（36/53）可能诊断，3.8%（2/53）不能诊断。治疗后6个月，EOS%、IgE、IgG、IgG4显著下降，补体C3、C4显著升高（均P<0.05），而且治疗后6个月的IgG4水平与基线时的C4呈负相关，与IgE、IgG4/IgG呈正相关。 结论： IgG4-RD是一组男性多发，多器官受累，伴随嗜酸性粒细胞、IgE、IgG、IgG1、IgG4升高，补体降低的免疫性疾病。外周血CD4+T淋巴细胞、Treg比例相对升高。糖皮质激素和免疫抑制剂治疗有效，治疗后6个月的IgG4水平与基线时的补体C4水平呈负相关，与IgE水平、IgG4/IgG呈正相关。.