Rebecca S. Bahn, M.D.

Rebecca S. Bahn, M.D., studies the pathogenesis of Graves' ophthalmopathy and autoimmune thyroid disease.

Focus areas

Dr. Bahn's laboratory is interested in the mechanisms and consequences of immune system activation of orbital preadipocyte fibroblasts, the target cells involved in Graves' ophthalmopathy.

Her team is studying the unique features of these that render them particularly susceptible to autoimmune attack in Graves' disease. Studies are under way to define retro-ocular, thyroid and pretibial cross-reactive antigens whose presence might help to explain the clinical associations between Graves' ophthalmopathy, pretibial dermopathy and Graves' hyperthyroidism.

Other studies in her laboratory include the analysis, using gene array technology, of genes involved in the development of Graves' ophthalmopathy. She and her team have identified several adipogenesis-related and immune system genes that may have novel roles in this disease process.

Dr. Bahn's team has shown that thyroid-stimulating hormone receptor (TSHR), the autoimmune target in Graves' hyperthyroidism, is expressed to a greater degree in orbital connective tissue explants from patients with Graves' ophthalmopathy than in normal orbital tissue.

This antigen appears to be expressed in the fat cells within the orbit. Her team's in vitro studies have shown that autoantibodies directed against the TSHR that circulate in the blood of patients with Graves' disease and Graves' ophthalmopathy stimulate these cells to turn into fat cells and produce substances known to accumulate in the orbits of patients with this condition.

Her laboratory has recently turned its attention to studies of a novel small drug-like molecule that attaches to the TSHR receptor on orbital fibroblasts and inhibits the ability of TSHR autoantibodies to affect these cells. In the future, clinical trials may test whether these small molecules might be used as therapy for Graves' disease and Graves' ophthalmopathy.

Significance to patient care

Dr. Bahn's group also is currently performing a clinical trial of rituximab in the treatment of severe active Graves' ophthalmopathy.

If this medication is proven effective in the treatment of Graves' ophthalmopathy, it will likely become a mainstay of therapy for this difficult-to-treat condition.