RT Journal Article
SR Electronic
T1 Serum IgG2 and tissue IgG2 plasma cell elevation in orbital IgG4-related disease (IgG4-RD): Potential use in IgG4-RD assessment.
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 1576
OP 1582
DO 10.1136/bjophthalmol-2017-310148
VO 101
IS 11
A1 Anita S Y Chan
A1 Hardeep Mudhar
A1 Sunny Yu Shen
A1 Stephanie S Lang
A1 Malee Fernando
A1 Maryam Hazly Hilmy
A1 Naomi Jayne Guppy
A1 Ian Rennie
A1 Lisa Dunkley
A1 Issam Al Jajeh
YR 2017
UL http://bjo.bmj.com/content/101/11/1576.abstract
AB Aims 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.Methods 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.Results 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).Conclusions 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.