Objective: To analyze the clinicopathological characteristics of IgG4-related sialadenitis (IgG4-RS). Methods: A total of 40 cases diagnosed with IgG4-RS were collected from the Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2019 to December 2022. Among them, there were 26 males and 14 females. The age range was 29-77 years old [(59.4±11.8) years old], with 23 patients being older than 60 years. The lesion site, imaging manifestations, histopathological features, serological test and treatment information of patients were collected. The expression of IgG4 and IgG proteins was detected by immunohistochemistry. Results: Submandibular region swelling was the most common initial symptom of IgG4-RS (38/40, 95.0%). All the patients having serum IgG4 levels> 1.35 g/L. Serum IgG4 levels were significantly increased in patients aged>60 years (Z=-2.45, P=0.014) and those involving multiple glands (Z=-2.04, P=0.042). Thirty six cases received major salivary gland biopsy, and all the cases showed dense lymphocyte and plasma cell infiltration. Lymphoid follicle, storiform fibrosis and obliterative phlebitis were seen in 88.9% (32/36), 63.9% (23/36), 30.6% (11/36) of the cases, respectively. Twenty one cases received labial salivary gland biopsy, 66.7% (14/21) showed lymphocyte and plasma cell infiltration, 19.0% (4/21) had lymphoid follicle structures, and 33.3% (7/21) showed no obvious histological abnormalities. No signs of fibrosis or obliterative phlebitis were observed in all labial salivary gland biopsies. And 95.0% (38/40) of cases had IgG4 positive plasma cell>10/HPF, 82.5% (33/40) of cases had IgG4/IgG positive plasma cell ratio>40%. All the patients had a decrease in serum IgG4 levels after glucocorticoid treatment, but only 21.4% (6/28) of cases had reduced to normal levels (≤1.35 g/L), and there were still significant fluctuations in serum IgG4 levels thereafter. Conclusions: IgG4-RS has a predilection for middle-aged and elderly male patients, and serum IgG4 levels are significantly related to the patient's age and whether multiple glands are involved. Labial salivary gland biopsy cannot replace submandibular gland for histopathological evaluation. It is a common phenomenon that serum IgG4 levels cannot restored to normal levels after glucocorticoid treatment. This study provides certain assistance for clinical and pathological diagnosis of IgG4-RS. This study is beneficial for further understanding IgG4-RS and improving the clinical and pathological diagnosis of the disease.
目的： 探讨IgG4相关唾液腺炎（IgG4-related sialadenitis，IgG4-RS）的临床病理特征。 方法： 收集2019年1月至2022年12月于上海交通大学医学院附属第九人民医院口腔病理科诊断为IgG4-RS的患者共40例，男性26例，女性14例，年龄（59.4±11.8）岁（29~77岁），其中23例患者年龄>60岁。收集患者的病变部位、影像学表现、组织病理学特征、血清学检查结果及治疗信息，采用免疫组化方法检测组织中IgG4和IgG蛋白表达。 结果： 颌下区肿胀是IgG4-RS最常见的首发症状［95%（38/40）］，所有患者血清IgG4水平均>1.35 g/L，血清IgG4水平在年龄>60岁的患者（Z=-2.45，P=0.014）和累及多组腺体的患者（Z=-2.04，P=0.042）中均显著升高。36例大唾液腺活检组织中，所有患者均可见致密淋巴细胞、浆细胞浸润，淋巴滤泡形成、席纹状纤维化和闭塞性静脉炎分别见于88.9%（32/36）、63.9%（23/36）和30.6%（11/36）的患者。21例唇腺活检组织中，66.7%（14/21）可见淋巴细胞、浆细胞浸润，19.0%（4/21）可见淋巴滤泡形成，33.3%（7/21）组织学表现无明显异常，所有唇腺活检组织中均未见纤维化及闭塞性静脉炎表现。95.0%（38/40）患者中IgG4阳性浆细胞>10个/高倍视野，82.5%（33/40）患者中IgG4/IgG阳性浆细胞比值>40%。所有患者经糖皮质激素治疗后血清IgG4水平均有所下降，仅21.4%（6/28）患者可恢复到正常水平（≤1.35 g/L），且后续血清IgG4水平仍有显著波动。 结论： IgG4-RS主要好发于中老年男性患者，血清IgG4水平与患者年龄及是否累及多组腺体密切相关。唇腺活检不能替代下颌下腺进行组织病理学评估。治疗后血清IgG4水平不能恢复至正常水平是常见现象。.