A cell type that causes significant scarring in lung disease appears to have a similar effect in Graves' disease, University of Michigan Health System researchers have found. The cells, called fibrocytes, are present at a higher than normal frequency in patients with Graves' disease, according to a new study, the first to associate fibrocytes with this autoimmune disease.
The discovery is a major step forward in explaining how and why the orbit of the eye is subject to scarring and inflammation in Graves' disease.
The findings may also lead to new treatment strategies to target scarring or fibrosis, say authors Raymond Douglas, M.D., Ph.D., and Terry Smith, M.D., specialists in Graves' disease at the University of Michigan Kellogg Eye Center. The study appears in the January issue of the Journal of Clinical Endocrinology & Metabolism.
Graves' disease is an autoimmune disorder which results in an overactive thyroid. Up to half of those affected by the disease will develop inflammation or fibrosis around their eyes, creating the bulging appearance associated with Graves' eye disease, also called thyroid-associated ophthalmopathy. Excessive scarring can cause such manifestations as double vision or even loss of vision.
"Today we have medications to reduce inflammation, but these drugs typically do not treat the fibrotic effects of thyroid eye disease," says Douglas, oculoplastics surgeon. "Our study is the first to implicate fibrocytes in the disease process, a finding that should open up new possibilities for treatment."
Fibrocytes are immune cells derived from bone marrow that circulate through the bloodstream. They can infiltrate tissue, like the lungs, kidney, and liver, generating excess connective tissue and areas of fibrosis, for example, following pulmonary or kidney injury.