Orthotopic liver transplantation for familial amyloidotic polyneuropathy: A pathological study

Familial amyloidotic polyneuropathy (FAP),a hereditary form of systemic amy loidosis with clinically significant neuropathy and cardiomyopathy, is caus ed by a genetic defect of the transthyretin gene, which is mostly synthesiz ed in the liver. Orthotopic liver transplantation (OLT) is thought to elimi nate the amyloidogenic protein and currently is the only definitive treatme nt for this disorder. The aim of this study was to define the distribution and extent of amyloid deposition in tissues from these patients and evaluat e the suitability of the resected FAP livers for transplantation into non-F AP patients. Surgical specimens from 14 patients removed at the time of OLT and autopsy tissues from 3 of the 14 were examined histologically using he matoxylin and eosin and Congo red-stained sections. The extent of amyloid d eposits was evaluated, semiquantitatively graded from negative to marked, a nd correlated with clinical course and patient outcome. Amyloid deposits we re consistently seen in hilar and vagus nerves. Liver lobular involvement w as minimal in 1 and absent in the other 13 cases, with portal arterial amyl oid deposits seen in 7 cases. At autopsy, extensive amyloid deposition in t he heart was seen in all 3 cases with involvement of the conduction system. The extent of amyloid deposition at OLT did not correlate with the duratio n of symptoms before OLT or patient outcome after OLT. in conclusion, Liver parenchymal involvement in FAP is minimal, and these explants are suitable for grafting in non-FAP patients. The recipients of such grafts must be ca refully observed for the development of any amyloid-related disease, partic ularly cardiomyopathy. Of the tissues removed at OLT, the histopathologic c onfirmation of FAP is most consistently made by the examination of hilar an d vagus nerves. HUM PATHOL 31:40-44. Copyright (C) 2000 by W.B. Saunders Co mpany.