Advanced glycation end product in familial amyloidotic polyneuropathy (FAP).

Abstract

OBJECTIVES: Advanced glycation end products (AGE) are present in amyloid deposits in beta2-microglobulin amyloidosis, and it has been postulated that glycation of beta2-microglobulin may be involved in fibril formation. The aim of this paper was to ascertain whether AGE occur in amyloid deposits in familial amyloidotic polyneuropathy (FAP). SETTING: Department of Medicine, Umeå University Hospital and First Department of Internal Medicine, Kumamoto University School of Medicine. DESIGN: The presence of AGE was sought immunohistochemically and biochemically in amyloid-rich tissues from patients with FAP. SUBJECTS: Biopsy specimens from nine patients and 10 controls were used for the immunohistochemical analysis. For amyloid preparation, vitreous samples from three FAP patients were used. RESULTS: Immunohistochemical studies using a polyclonal anti-AGE antibody revealed positive immunoreactivity in intestinal materials, but the pattern of reactivity was unevenly distributed; it was often present in the border of amyloid deposits, or surrounding them. Non-amyloid associated immunoreactivity was also observed in a few regions of the specimens, although the AGE-positive structures were situated in areas containing amyloid deposits. Western blotting of purified amyloid from the vitreous body of FAP patients revealed a significant association of AGE with amyloid fibrils. CONCLUSION: The immunoreactivity for the AGE antibody suggests that AGE may be involved in fibril formation in FAP.