Antibodies against Calsequestrin and Type XIII Collagen are Good Markers for Chronic Upper Eyelid Retraction

Abstract

Purpose: Chronic upper eyelid retraction is a common manifestation of thyroid-associated ophthalmopathy (TAO) but can occur as a dominant feature of ophthalmopathy in patients with Graves’ hyperthyroidism and in association with Hashimoto's thyroiditis in the absence of other eye signs except mild proptosis. Methods: We measured antibodies against calsequestrin, flavoprotein (Fp), G2s, and collagen XIII in an enzyme-linked immunosorbent assay (ELISA) in 15 patients with chronic upper eyelid retraction. Results: Calsequestrin antibodies were detected in 67% of patients with upper eyelid retraction, Fp antibodies in 47%, G2s antibodies in 20%, and collagen XIII antibodies were detected in 40% of these patients at the first visit. These prevalences were significantly greater than normal for calsequestrin and collagen XIII, but not for Fp and G2s antibodies. On follow-up, calsequestrin antibodies were detected in two more patients, for an overall prevalence of 80%. Levels of the four antibodies remained fairly constant over the study period and generally correlated with the presence and severity of upper eyelid signs. Conclusions: These findings support the notion that autoimmune attack against calsequestrin and collagen XIII in the levator palpebrae superioris (LPS) muscle may play a role in the pathogenesis of upper eyelid retraction and that lid retraction may be the dominant feature of ophthalmopathy in patients with Hashimoto's thyroiditis and non-autoimmune thyroid disease. Because calsequestrin is an intracellular protein, the corresponding autoantibodies probably do not initiate LPS muscle inflammation but may contribute to its damage. The mix of antibodies against calsequestrin and collagen XIII may shed light on the diverse presentations found in thyroid-associated ophthalmopathy.

KEYWORDS:

• Calsequestrin
• collagen XIII
• upper eyelid retraction
• Graves’ disease
• Hashimoto's thyroiditis
• levator palpebrae superioris muscle