IMMUNOHISTOCHEMICAL ANALYSIS OF LATTICE CORNEAL DYSTROPHIES TYPE-I AND TYPE-II

Corneal buttons from four patients with lattice corneal dystrophy (LD) type I, thought to be an isolated corneal amyloidosis, and from six p atients with LD type II, part of systemic familial amyloidosis, Finnis h type (FAF; Meretoja's syndrome), were studied by immunohistochemistr y to determine the differential distribution in the amyloid deposits o f amyloid P component (AP), mutated gelsolin specific for FAF, and nat ive gelsolin. In both types of LD, antibodies to AP labelled lattice l ines and a discontinuous layer of amyloid deposits under Bowman's laye r. In LD type II, particularly, they also reacted with streak-like amy loid deposits between corneal almellae, especially in the limbal regio n. While the anti-FAF antiserum strongly labelled all amyloid deposits in LD type II, it failed to react unequivocally with them in LD type I. Both in LD type I and in two control specimens representing granula r dystrophy, the monoclonal antibody (MAb) GS-2C4 to gelsolin faintly labelled some deposits, while in LD type II it reacted non-homogeneous ly with most amyloid deposits. In all specimens, MAb GS-2C4 labelled c orneal epithelial cells and occasional stromal keratocytes and endothe lial cells. The results suggest that Meretoja's syndrome, a systemic d isease, can be diagnosed even retrospectively from corneal buttons sub jected to histopathological study.