[Amyloid neuropathies. Histopathological study of peripheral nerve biopsy in 18 cases].Ann Pathol. 2003 Apr; 23(2):114-20.AP
A retrospective study of nerve and muscle biopsies since 1983, with probable amyloidosis, has been performed.
MATERIALS AND METHODS
Eighteen nerve and muscle biopsies, out of 29, were selected.
Endoneurial amyloid deposits were visible on routine sections in 11 cases, revealed by ultrastructural study in 4 cases and by Congo red and/or thioflavine stains in 3 others. Amyloid deposits were marked by anti-transthyretin (TTR) serum in 13 patients, within endoneurium in 11 cases, and only around muscle fibers in 2 others. A mutation in the TTR gene, usually Val30Met, was evidenced in 8 cases and could not be assayed in the 5 others. An immunoglobulin light chain was revealed in amyloid deposits by direct immunofluorescence in the 5 other patients, of whom 4 had multiple myeloma and the fifth a lambda light chain Bence-Jones proteinuria.
Nerve biopsy revealed amyloidosis in 10 patients: 5 of them had a mutation in TTR gene, without any family history.