Paranodal dissection in chronic inflammatory demyelinating polyneuropathy with antineurofascin-155 and anticontactin-1 antibodies

Objective

To investigate the morphological features of chronic inflammatory demyelinating polyneuropathy (CIDP) with autoantibodies directed against paranodal junctional molecules, particularly focusing on the fine structures of the paranodes.

Methods

We assessed sural nerve biopsy specimens obtained from 9 patients with CIDP with antineurofascin-155 antibodies and 1 patient with anticontactin-1 antibodies. 13 patients with CIDP without these antibodies were also examined to compare pathological findings.

Results

Characteristic light and electron microscopy findings in transverse sections from patients with antineurofascin-155 and anticontactin-1 antibodies indicated a slight reduction in myelinated fibre density, with scattered myelin ovoids, and the absence of macrophage-mediated demyelination or onion bulbs. Teased-fibre preparations revealed that segmental demyelination tended to be found in patients with relatively higher frequencies of axonal degeneration and was tandemly found at consecutive nodes of Ranvier in a single fibre. Assessment of longitudinal sections by electron microscopy revealed that detachment of terminal myelin loops from the axolemma was frequently found at the paranode in patients with antineurofascin-155 and anticontactin-1 antibody-positive CIDP compared with patients with antibody-negative CIDP. Patients with antineurofascin-155 antibodies showed a positive correlation between the frequencies of axo–glial detachment at the paranode and axonal degeneration, as assessed by teased-fibre preparations (p<0.05).

Conclusions

Paranodal dissection without classical macrophage-mediated demyelination is the characteristic feature of patients with CIDP with autoantibodies to paranodal axo–glial junctional molecules.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2iBU3HR
via IFTTT