Cytokine profiles in clinical subtypes of ophthalmic Graves' disease

The "Quiet TED"-A Special Subgroup of Thyroid Eye Disease

PURPOSE

Thyroid eye disease (TED) or Graves' orbitopathy starts with an active inflammatory stage (active disease) followed by resolution of inflammation and progression to a fibrotic, inactive stage. In our practice, we have encountered cases that have not had active disease despite presence of fibrotic sequelae and disease progression. We aim to delineate the clinical characteristic of this unique group of patients.

METHODS

We conducted a single-center (Mayo Clinic Rochester) retrospective chart review of TED patients who throughout the course of their disease had only evidence for inactive TED, defined as clinical activity score <3.

RESULTS

Median age in the cohort (n = 19) was 54 years (IQR 47-61). 58% had a prior diagnosis of Graves' disease (GD) before referral. 80% (n = 15) were euthyroid at the time of TED onset (median thyroid-stimulating hormone 1.7 mIU/L). The most common finding was diplopia (100%, n = 19) followed by proptosis (63%, n = 12). Interestingly the disease was asymmetric in 42% of cases. Overall median clinical activity score on presentation was 1 (IQR 0-1). Severity wise, 85% (n = 16) of patients were classified as moderate-to-severe during follow up. Orbital decompression was performed in only 1 case, while extraocular muscle surgery was performed in 13 cases.

CONCLUSIONS

Quiet TED is a subgroup of TED patients that defies the classic disease paradigm. It presents primarily with diplopia and proptosis. Further evaluation of this group might identify useful insights in TED pathophysiology and help optimize therapeutic choices.

Insights Into Local Orbital Immunity: Evidence for the Involvement of the Th17 Cell Pathway in Thyroid-Associated Ophthalmopathy

CONTEXT

Unique features of local immunity in thyroid-associated ophthalmopathy (TAO) may affect disease progression.

OBJECTIVE

To investigate the association between the orbital immune microenvironment and TAO development.

DESIGN/SETTING/PARTICIPANTS

TAO and control orbital connective tissues were collected.

MAIN OUTCOME MEASURES

Single-cell sequencing examined orbital lymphocytic infiltrates. Multicolor flow cytometry explored the phenotypes of different cell subsets and in vitro models for cell functional studies. Coculture experiment and western blotting assay were used to determine underlying mechanism of the enhanced T helper 17 (Th17) cell pathway.

RESULTS

The TAO orbital microenvironment was composed of natural killer cells, dendritic cells, macrophages, T cells, plasma cells, and CD34+ orbital fibroblasts, but few B cells. Increases in CD3+CD8- IL-17A-producing and RAR-related orphan receptor (ROR)γt-expressing T cells and in CD3+CD8- IL-13-producing and GATA3-expressing T cells suggested Th17 and Th2 cell responses in TAO orbits. Increased interferon-γ (IFN-γ)-producing and RORγt+Tbet+ T cells indicated a Th1-like phenotype of orbital-infiltrating Th17 cells. Higher IL-23R and IL-1R expression and lower IL-21R expression were also observed on Th17 cells in TAO orbits. Multivariate analyses revealed that the Th17 pathway [IL-17A (P = 0.001), IFN-γ (P = 0.009), RORγt (P = 0.003), IL-23R (P = 0.033), IL-21R (P = 0.019)], and Th2 pathway [IL-13 (P = 0.015), GATA3 (P = 0.012)] were associated with TAO. IL-17A, IL-23R, and IL-1R correlated with clinical activity score and visual acuity. CD34+ orbital fibroblasts exhibited distinct cell surface marker expression and promoted IL-23R and IL-1R expression on T cells to facilitate the Th17-cell phenotype through prostaglandin E2-EP2/EP4-cAMP signaling.

CONCLUSION

Our study addresses the importance of retroorbital immunity and suggests possible means of disrupting TAO pathogenesis.

Transcriptome Analysis of Orbital Adipose Tissue in Active Thyroid Eye Disease Using Next Generation RNA Sequencing Technology

Objective:

This study utilized Next Generation Sequencing (NGS) to identify differentially expressed transcripts in orbital adipose tissue from patients with active Thyroid Eye Disease (TED) versus healthy controls.

Method:

This prospective, case-control study enrolled three patients with severe, active thyroid eye disease undergoing orbital decompression, and three healthy controls undergoing routine eyelid surgery with removal of orbital fat. RNA Sequencing (RNA-Seq) was performed on freshly obtained orbital adipose tissue from study patients to analyze the transcriptome. Bioinformatics analysis was performed to determine pathways and processes enriched for the differential expression profile. Quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR) was performed to validate the differential expression of selected genes identified by RNA-Seq.

Results:

RNA-Seq identified 328 differentially expressed genes associated with active thyroid eye disease, many of which were responsible for mediating inflammation, cytokine signaling, adipogenesis, IGF-1 signaling, and glycosaminoglycan binding. The IL-5 and chemokine signaling pathways were highly enriched, and very-low-density-lipoprotein receptor activity and statin medications were implicated as having a potential role in TED.

Conclusion:

This study is the first to use RNA-Seq technology to elucidate differential gene expression associated with active, severe TED. This study suggests a transcriptional basis for the role of statins in modulating differentially expressed genes that mediate the pathogenesis of thyroid eye disease. Furthermore, the identification of genes with altered levels of expression in active, severe TED may inform the molecular pathways central to this clinical phenotype and guide the development of novel therapeutic agents.

The Role of the Immune Response in the Pathogenesis of Thyroid Eye Disease: A Reassessment

Background

Although thyroid eye disease is a common complication of Graves’ disease, the pathogenesis of the orbital disease is poorly understood. Most authorities implicate the immune response as an important causal factor. We sought to clarify pathogenesis by using gene expression microarray.

Methods

An international consortium of ocular pathologists and orbital surgeons contributed formalin fixed orbital biopsies. RNA was extracted from orbital tissue from 20 healthy controls, 25 patients with thyroid eye disease (TED), 25 patients with nonspecific orbital inflammation (NSOI), 7 patients with sarcoidosis and 6 patients with granulomatosis with polyangiitis (GPA). Tissue was divided into a discovery set and a validation set. Gene expression was quantified using Affymetrix U133 Plus 2.0 microarrays which include 54,000 probe sets.

Results

Principal component analysis showed that gene expression from tissue from patients with TED more closely resembled gene expression from healthy control tissue in comparison to gene expression characteristic of sarcoidosis, NSOI, or granulomatosis with polyangiitis. Unsupervised cluster dendrograms further indicated the similarity between TED and healthy controls. Heat maps based on gene expression for cytokines, chemokines, or their receptors showed that these inflammatory markers were associated with NSOI, sarcoidosis, or GPA much more frequently than with TED.

Conclusion

This is the first study to compare gene expression in TED to gene expression associated with other causes of exophthalmos. The juxtaposition shows that inflammatory markers are far less characteristic of TED relative to other orbital inflammatory diseases.