New classification of autoimmune neuropathies based on target antigens and involved domains of myelinated fibres.

ABSTRACT

Autoimmune neuropathies are named by eponyms, by descriptive terminology or because of the presence of specific antibodies and are traditionally classified, on the basis of pathology and electrophysiology, as primary demyelinating or axonal. However, autoimmune disorders targeting specific molecules of the nodal region, although not showing pathological evidence of demyelination, can exhibit all the electrophysiological changes considered characteristic of a demyelinating neuropathy and acute neuropathies with antiganglioside antibodies, classified as axonal and due to nodal dysfunction, can present with reversible conduction failure and prompt recovery that appear contradictory with the common view of an axonal neuropathy. These observations bring into question the concepts of demyelinating and axonal nerve conduction changes and the groundwork of the classical dichotomous classification.We propose a classification of autoimmune neuropathies based on the involved domains of the myelinated fibre and, when known, on the antigen. This classification, in our opinion, helps to better systematise autoimmune neuropathies because points to the site and molecular target of the autoimmune attack, reconciles some contrasting pathological and electrophysiological findings, circumvents the apparent paradox that neuropathies labelled as axonal may be promptly reversible and finally avoids taxonomic confusion and possible misdiagnosis.