[Lesion mechanism dependent, differential changes in neurofilaments and microtubules: a pathological and experimental study].

INTRODUCTION

The consequences of axonal or demyelinating injuries on the axonal cytoskeleton have rarely been described.

METHODS

We have compared the density of fibers labeled by anti-neurofilaments (NF) and -beta tubulin (TUB) to the density of total fibers in nine patients with axonal neuropathies of undetermined etiology (AUE), six with necrotizing angeitis with neuropathy (NAN), seven with chronic inflammatory demyelinating neuropathy (CIDP) and in five controls, as well as in six patients with chronic multiple sclerosis (MS). We also studied demyelinated rat corpus callosum after lysophosphatidyl (LPC) microinjection.

RESULTS

In AUE and NAN NF positive fibers decreased together with total fiber density, whereas TUB increased. In demyelinating lesions TUB was not altered (CIDP) or strongly decreased (MS, LPC); NF were strongly reduced in MS (where axon loss was prominent) and in LPC lesions (despite the lack of fiber degeneration) and for fiber densities<3900/mm2 in CIDP.

CONCLUSION

The initial mechanism of a disease, either axonal degeneration or demyelination, could result into a specific pattern of axonal cytoskeleton alterations.