Usefulness of sural nerve biopsy in the genomic era

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Neuropathology. 2009 May 22.

Usefulness of sural nerve biopsy in the genomic era.

Kanda T.

Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate

School of Medicine, Yamaguchi, Japan.

The value of peripheral nerve biopsy is now sometimes questioned due to the high

complication rate and the recent development of noninvasive molecular techniques

for diagnosis of hereditary neuropathy. However, the disorders that can be

diagnosed by genetic analysis are limited and sural nerve biopsy is still a

powerful tool for making a correct diagnosis of peripheral neuropathy.

Histological evaluation of the sural nerve has long focused on changes of the

two major components of peripheral nerves, axons and myelin, as well as on the

detection of diagnostic changes such as amyloid deposits, sarcoid tubercles, and

vasculitis.

In addition to these components, the sural nerve biopsy specimen contains

various important cells, including perineurial cells, mast cells, endothelial

cells, pericytes, and lymphocytes. Among these cells, the endothelial cells and

pericytes form the blood-nerve barrier (BNB) and investigation of these cells

can reveal important information, especially in inflammatory neuropathies.

To better understand the biological basis of BNB, we established rat and human

immortal cell lines from the endothelial cells and pericytes of endoneurial

microvessels. Characterization of these cell lines is now underway at our

laboratory. These BNB cell lines should provide useful information concerning

the pathophysiology of peripheral neuropathy, and we should obtain a new

perspective for the investigation of nerve biopsy specimens after understanding

the molecular background of the BNB.