Plasma cell IgG4 positivity in orbital biopsies of non-IgG4-related conditions

Antonio A V Cruz; Maria A B Camacho; Barbara S Cunha; Hind M Alkatan; Naiara F Xavier

doi:10.4103/SJOPT.SJOPT_91_21

Plasma cell IgG4 positivity in orbital biopsies of non-IgG4-related conditions

Saudi J Ophthalmol. 2021 Nov 17;35(3):193-197. doi: 10.4103/SJOPT.SJOPT_91_21. eCollection 2021 Jul-Sep.

Authors

Antonio A V Cruz¹, Maria A B Camacho¹, Barbara S Cunha¹, Hind M Alkatan^{2

3}, Naiara F Xavier¹

Affiliations

¹ Department of Ophthalmology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
² Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
³ Department of Pathology, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia.

Abstract

The IgG4-related disease (IgG4-RD) is a systemic condition defined as a fibro-inflammatory disorder, characterized by the occurrence of tumor-like lesions in multiple organs including the eye adnexa. The main diagnostic criterion is based on histopathological findings, especially on the IgG4⁺/IgG⁺ plasma cell ratio. In this article, we reviewed the literature of non-IgG4-RD orbital conditions with IgG4 positivity. There were 20 reports of inflammatory non-IgG4-RD orbital lesions and 14 reports of orbital lymphoid proliferations with significant IgG4 positivity. The role of plasma cells IgG4 in the pathogenesis of non-IgG4-RD is not clear. Considering the large spectrum of diseases caused by a variety of different etiopathogenic mechanisms, we think that the common denominator of IgG4⁺ in these conditions might be related to the peculiar properties of down regulation of immune response of the IgG4 and not to a specific link to IgG4-RD.

Keywords: IgG4; IgG4-related disease; IgG4/IgG ratio; RosaiDorfman disease; orbit.