Abstract
Purpose :
The diagnosis of IgG4-related orbitopathy is by convention based on histopathology. However, orbital biopsies are often only performed after clinical recurrence or resistance to a course of systemic steroid therapy. Our case series supports the hypothesis that IgG4 positive plasma cells can decrease following steroid use; this can interfere with the final diagnosis.
Methods :
We performed a chart review of four patients with suspicion of IgG4-related orbitopathy between 2017 and 2018 in a single tertiary center. All patients underwent biopsies after weeks to months of starting oral steroid treatment. A total of one orbit, one conjunctiva, and four lacrimal gland specimens were analyzed. A literature review was conducted.
Results :
All patients presented an indolent course (5-24 months) of either upper lid swelling or unilateral proptosis. Imaging findings ranged from an enlargement of the lacrimal gland and/or extraocular muscles, to an intraorbital extraconal mass. Sarcoidosis, lymphoma, thyroid disease and other inflammatory conditions were ruled out. All patients improved markedly following the initiation of oral steroids. After steroid taper, recurrence occurred over a period of two to five months. At that time, the biopsies all showed lymphocytic proliferation and sclerosis suggestive of chronic inflammation. A dense lymphoplasmatic infiltrate was found in three cases. Two of the four patients’ specimens showed storiform sclerosis, a well-known histologic feature of IgG4-related disease. Although it is recognized that serum IgG4 is not a specific indicator, one patient had extremely high levels of serum IgG4 of 2330 mg/dL (N under 135 mg/dL). These features suggest IgG4-related disease, yet none of the specimens met the gold standard IgG4:total IgG cut-off of 40%.
Conclusions :
A literature review revealed no clear relationship between systemic steroid therapy and levels of IgG4 positive plasma cells. The cases herein raise the question if there exists a spectrum of treated IgG4-related disease that do not meet the currently accepted IgG4:total IgG cut-off. Instead of relying on histopathology, a diagnosis of IgG4-related orbitopathy should be based on a multidisciplinary evaluation.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.