Keratoepithelin in secondary corneal amyloidosis

Area of Science:

• Ophthalmology
• Corneal Diseases
• Protein Biochemistry

Background:

• Amyloid deposits are characteristic of several corneal dystrophies, including lattice corneal dystrophies (LCD).
• Transforming growth factor-beta-induced gene (TGFBI) mutations encoding keratoepithelin (KE) are linked to primary hereditary corneal dystrophies.
• The presence of KE in secondary corneal amyloid deposits remained uninvestigated.

Purpose of the Study:

• To determine if keratoepithelin (KE) is a component of secondary corneal amyloid deposits.
• To compare KE presence in secondary amyloidosis with primary amyloid deposits in lattice corneal dystrophies.

Main Methods:

• Immunohistochemical staining using a polyclonal antibody against KE was performed on corneal tissues with secondary amyloidosis.
• Five corneal buttons with secondary amyloidosis (due to Fuchs endothelial dystrophy) were analyzed.
• Controls included cases of lattice corneal dystrophy type I (positive) and corneas without amyloid (negative).

Main Results:

• Keratoepithelin (KE) staining was positive in all corneas with secondary amyloidosis and lattice corneal dystrophy type I.
• KE was localized in subepithelial pannus and anterior stroma in secondary amyloidosis cases.
• KE exhibited a granular appearance in amyloid deposits across all analyzed specimens.

Conclusions:

• Keratoepithelin (KE) is a component of secondary amyloid deposits in the cornea.
• This finding extends the known presence of KE beyond primary hereditary corneal dystrophies to secondary amyloidosis of diverse origins.