Transthyretin familial amyloidotic polyneuropathy: histopathological study of the explanted livers

FAP is an autosomal dominant inherited disease, characterized by systemic deposition of amyloid fibrils in various tissues. The purpose of this study is to describe the gross and microscopic findings of the explanted livers for FAP.10 patients were transplanted for FAP at our institution. Diagnosis was supported by positive familiar history, clinical data and detection of mutated TTR by electrospray ionization mass spectrometry with Val30Met mutation verified by PCR. All the explanted livers were photographed, fixed in formol and processed according to protocol. Later they were examined with HyE, reticulin, PAS diastasa, Masson trichromic, Congo red with polarised light and immunoreactivity against TTR. The gross aspect was normal. We obtained multiple samples representative of the organ and the hepatic hilium. All of the patients presented with deposits of amyloid substance in the lymph nodes and the nerves of the hepatic hilium These deposits were Congo red positive with a greenish birefringence to polarized light Deposits show immunoreactivity with antihuman TTR. Whereas liver transplantation restores hepatic function in patients with cirrhosis, liver transplantation cures the FAP patient of their genetic defect. Domino transplantation is a procedure in which the index patient receives an organ, while the explanted organ is reused for transplantation into another patient. In conclusion, exclusion of hepatic amyloid deposits which can cause functional alterations in the FAP liver is vital; and is important to study the explanted livers of patients with FAP to confirm the results of the scarce published series.