Neuromuscular

Neuropathy with IgM anti-MAG antibodies


stain
Anti-MAG antibodies: Nerve Histology
  Myelinated Axons: Reduced numbers
  No inflammation
  Subperineurial edema: Mild

VvG stain


H&E stain
Anti-MAG antibodies: Nerve Histology
  Myelinated Axons: Reduced numbers

VvG stain

Gomori trichrome stain


Neurofilament stain
Anti-MAG antibodies: Nerve Patholology
  Larger Axons: Reduced numbers
  Small axons: Relatively preserved
  Non-myelinating Schwann cells (Below): Diffusely distributed in endoneurium

NCAM stain


NCAM (Green) + P0 (Red) stain
Axon loss: Severe
Most Schwann cells have a denervated phenotype: Express both NCAM & P0

Büngner band cells
  Peripheral nerve Schwann cells with no asociated axon
Ultrastructure


NCAM (Green) + MBP (Red) stain stain
Axon loss: Moderate
Myelinating Schwann cells contain both NCAM & MBP


VvG stain

No endoneurial C5b-9 staining

C5b-9 stain

Scattered endoneurial histiocytes

Acid phosphatase stain

No segmental demyelination
  All larger axons have surrounding P0 stained myelin

Neurofilament (Green) + P0 (Red) stain

stain
Myelin sheaths around remaining larger axons: Often have irregular shapes
stain

stain
Myelin sheaths around remaining larger axons: Often have irregular shapes & staining
stain
stain

MAG Neuropathy: Nerve & Myelin Ultrastructure

From: R Schmidt
Myelin sheaths may have abnormal folded shapes

From: R Schmidt

MAG neuropathy: Thin myelin sheath surrounded by Schwann cell processes

From: R Schmidt


From: R Schmidt
MAG neuropathy: Myelin wide spacing & irregular shaped layers

From: R Schmidt

From: R Schmidt

From: R Schmidt


From: R Schmidt
MAG neuropathy: Myelin wide spacing with separation of layers of compact myelin

From: R Schmidt

From: R Schmidt
MAG neuropathy: Myelin wide spacing with separation of layers of compact myelin

From: R Schmidt

From: R Schmidt

MAG neuropathy: Pathology of Schmidt-Lanterman clefts

From: R Schmidt

From: R Schmidt

From: R Schmidt

From: R Schmidt

From: R Schmidt

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7/25/2022