Chan Anita S Y, Mudhar Hardeep, Shen Sunny Yu, Lang Stephanie S, Fernando Malee, Hilmy Maryam Hazly, Guppy Naomi Jayne, Rennie Ian, Dunkley Lisa, Al Jajeh Issam
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
Department of Anatomical Pathology, Singapore General Hospital, Singapore, Singapore.
Br J Ophthalmol. 2017 Nov;101(11):1576-1582. doi: 10.1136/bjophthalmol-2017-310148. Epub 2017 Mar 28.
To determine the role of serum and tissue IgG2 in orbital biopsies with the histological features of IgG4-related disease (IgG4-RD) in comparison with non-IgG4-related orbital inflammatory disorders (OID), including autoimmune disorders.
This is an international (Sheffield, UK, and Singapore) collaborative, retrospective case review of 69 patients (38 from Singapore National Eye Centre and 31 from Royal Hallamshire Hospital, Sheffield) with orbital inflammatory biopsies between 2002 and 2016. Clinical information and histology were reviewed and cases were classified into three groups: Group 1: IgG4-RD orbital inflammation (n=43); Group 2: idiopathic OID (n=12) and Group 3: autoimmune OID (n=14). Serum IgG1, IgG2, IgG3 and IgG4 levels were collated where available and immunohistochemistry (IHC) for tissue IgG2 plasma cells was performed.
Dual IHC showed IgG2 plasma cells as a distinct population from IgG4 plasma cells. Significant (twofold) serum IgG2 elevation was noted among IgG4-RD (group 1), idiopathic (group 2) and autoimmune OID (group 3). Similarly, significant elevation of tissue IgG2 plasma cells was also seen among IgG4-RD (group 1), idiopathic and autoimmune OID (groups 2 and 3).
Significant elevations of serum IgG2 and tissue IgG2 plasma cells are present in orbital IgG4-RD in comparison with non-IgG4 orbital inflammation (idiopathic and autoimmune OID), suggesting that IgG2 may play a role in IgG4-RD. A serum IgG2 cut-off >5.3 g/L was found to be 80% sensitive and 91.7% specific for orbital IgG4-RD, with an accuracy of 0.90. Tissue IgG2 and IgG4 subclass reporting may provide additional insight regarding the 'IgG4-RD' pathogenesis.
与非IgG4相关眼眶炎性疾病（OID）（包括自身免疫性疾病）相比，确定血清和组织IgG2在具有IgG4相关疾病（IgG4-RD）组织学特征的眼眶活检中的作用。
这是一项国际（英国谢菲尔德和新加坡）合作的回顾性病例研究，对2002年至2016年间69例眼眶炎性活检患者（38例来自新加坡国立眼科中心，31例来自英国谢菲尔德皇家哈勒姆郡医院）进行研究。回顾临床信息和组织学检查，病例分为三组：第1组：IgG4-RD眼眶炎症（n = 43）；第2组：特发性OID（n = 12）；第3组：自身免疫性OID（n = 14）。收集可得的血清IgG1、IgG2、IgG3和IgG4水平，并对组织IgG2浆细胞进行免疫组织化学（IHC）检测。
双重免疫组织化学显示IgG2浆细胞是与IgG4浆细胞不同的细胞群。在IgG4-RD（第1组）、特发性（第2组）和自身免疫性OID（第3组）中均观察到血清IgG2显著（两倍）升高。同样，在IgG4-RD（第1组）、特发性和自身免疫性OID（第2组和第3组）中也观察到组织IgG2浆细胞显著升高。
与非IgG4眼眶炎症（特发性和自身免疫性OID）相比，眼眶IgG4-RD中血清IgG2和组织IgG2浆细胞显著升高，提示IgG2可能在IgG4-RD中起作用。发现血清IgG2临界值>5.3 g/L对眼眶IgG4-RD的敏感性为80% , 特异性为91.7%，准确率为0.90。组织IgG2和IgG4亚类报告可能为“IgG4-RD”发病机制提供更多见解。
