Neuromuscular

U1RNP antibodies: Muscle Pathology

Capillary Pathology +
  Minimal Myopathy
  Active Myopathy

Endomysial Capillary Pathology with Minimal Myopathy

Endomysial Capillaries   Morphology: Large; Moderately thick walls
  Endothelium
    Acid phosphatase
    ATPase
    Ulex stain: Capillaries Large & Reduced numbers
  MxA stain: Increased
  C5b-9 deposition
Muscle Fibers
  Morphology: Normal
  MHC Class I: Increased expression

H&E stain
Endomysial Capillaries
  Large
  Basal lamina & Endothelial cells: Prominent
  Scattered through muscle
Muscle fibers
  Size variation: Moderate
  Smaller fibers: Intermediate size

H&E stain

Gomori trichrome stain
Endomysial Capillaries
  Large
  Basal lamina & Endothelial cells: Prominent
  Scattered through muscle
Muscle fibers
  Size variation: Moderate
  Smaller fibers: Intermediate size

VvG stain

Acid Phosphatase stain
Endomysial Capillaries
  Endothelial cells: Acid phosphatase staining

Acid Phosphatase stain

Ulex stain
Endomysial Capillaries (Ulex stain): U1RNP patient above; Control below
  Numbers: Reduced
  Stain intensity: Abnormally pale
  Size: Large

Ulex stain

Ulex stain
Endomysial Capillaries (Ulex stain): U1RNP patient
  Numbers: Reduced
  Stain intensity: Abnormally pale
  Size: Large

Ulex stain
Endomysial Capillaries (Ulex stain): U1RNP patient above; Control below
  Numbers: Reduced
  Stain intensity: Abnormally pale
  Size: Large
  Control muscle (Below): Dark staining of small capillaries

Ulex stain

MxA stain
MxA stain: U1RNP patient
  Capillary-associated cells: Dark stain
  Muscle fibers: Mild cytoplasm stain

MxA stain
MxA stain (Ulex stain): U1RNP patient above; Control below
  Capillary-associated cells: Dark stain
  Muscle fibers: Mild cytoplasm stain
  Control muscle (Below): No staining of capillaries or muscle fibers

MxA stain

C5b-9 stain
C5b-9 stain: U1RNP patient
  Endomysial Capillary-associated
  Muscle fibers: No staining

C5b-9 stain

ATPase pH 4.3 stain
Endomysial Capillaries: Mild ATPase staining
Perimysial Connective Tissue: Replaced by fat (Above)

ATPase pH 4.3 stain

NADH stain
Endomysial Capillaries: Mild NADH staining
Muscle fibers: Mildly coarse internal architecture

NADH stain

Esterase stain
Neuromuscular Junctions: Normal
Muscle fibers: MHC1 upregulation

MHC I stain

Myopathy with Capillary Pathology


H&E stain
Active Myopathy: Features
  Capillaries
  Muscle fibers
  Connective tissue
  Inflammation

Gomori trichrome stain

VvG stain
Capillary Pathology

H&E stain
Endomysial Capillaries: Large size

VvG stain

VvG stain
Endomysial Capillaries: Acid phosphatase stains endothelium

Acid phosphatase stain
Endomysial Capillaries: ATPase stains endothelium

ATPase pH 4.3 stain
Endomysial Capillaries: Ulex lectin shows large size & Reduced numbers

UEA-I stain

UEA-I stain
Muscle Fiber Pathology

VvG stain
Muscle Fiber Pathology
  Sizes: Varied
  Many immature fibers
  Necrosis: Scattered fibers
  Myonuclei: Large

H&E stain
Muscle Fiber Pathology
  Necrotic fibers invaded & replaced by histiocytes

Acid phosphatase stain
Muscle Fiber Pathology
  MHC Class I: Upregulated by muscle fibers

MHC Class I stain
Muscle Pathology
  C5b-9 stains
    Cytoplasm of necrotic muscle fibers
    Endomysial connective tissue

C5b-9 stain
Perimysial Connective Tissue Pathology

H&E stain
Perimysial Pathology
  Perimysial Connective Tissue
    Structure: Damaged
    Contains: Large, Scattered Histiocytes
    Stains for: Alkaline phosphatase (Below)

Alkaline phosphatase stain

H&E stain
Inflammation
  Lymphocytes: Surround perimysial vessel

Gomori trichrome stain

VvG stain
Inflammation
  Lymphocytes: CD4 stains many endomysial cells

CD4 stain
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12/17/2023