Axon cytoskeleton ultrastructure in chronic inflammatory demyelinating polyneuropathy

Muscle Nerve. 2011 Sep;44(3):332-9. doi: 10.1002/mus.22069.

Abstract

Introduction: To detail the extent and pattern of axon cytoskeleton alterations in chronic inflammatory demyelinating polyneuropathy (CIDP).

Methods: Nerve biopsies from 7 cases of CIDP, including 4 cases with severe fiber loss, were compared with 5 controls by morphometric transmission electron microscopy (TEM).

Results: Despite demyelination of single fibers, myelin ultrastructure was otherwise normal. Contrary to immunolabeling, TEM revealed a decrease in neurofilament (NF) density in every case, although there were pronounced variations among fibers even in the same sample. The NF decrease reached the same extent in large- and small-diameter fibers. It was observed in normally myelinated fibers, suggesting they were demyelinated at a distance from the section. Minimal inter-NF distance increased roughly inversely to NF density. Microtubules increased in 3 cases previously characterized by increased growth-associated protein (GAP-43) immunolabeling.

Conclusion: These data demonstrate the severity and constancy of axonal lesions, and especially of NF, in residual fibers in our cases of CIDP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Axons / pathology
  • Axons / ultrastructure*
  • Biopsy
  • Case-Control Studies
  • Cytoskeleton / ultrastructure*
  • Female
  • GAP-43 Protein / metabolism
  • Humans
  • Male
  • Microtubules / ultrastructure
  • Middle Aged
  • Myelin Sheath / ultrastructure
  • Neurofibrils / ultrastructure
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / metabolism
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / pathology*
  • Severity of Illness Index

Substances

  • GAP-43 Protein