Ku

Ku antibody: Muscle Pathology

7 year old female: Proximal weakness, Rapidly progressive, without rash; CK up to 2,000

Inflammation: Lymphocytic, Perivascular
Myopathy
Muscle fibers
Immature, Many
Cytoplasm: Abnormal, Aggregates
C_5b-9 stain
Capillaries: Large
Other

Inflammatory Myopathy
Myopathy
Fiber sizes: Varied, Bimodal
Small muscle fibers: Basophilic cytoplasm
Immune cells, probably lymphocytes: In & around wall of perimysial vessel (Arrow)

Congo red stain

H&E stain

Myopathy
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers: Basophilic cytoplasm

H&E stain

H&E stain

Gomori trichrome stain

Inflammatory Myopathy
Myopathy
Fiber sizes: Varied, Bimodal
Small muscle fibers: Basophilic cytoplasm
Immune cells, probably lymphocytes: In & around wall of perimysial vessel

VvG stain

Myopathy
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers
Irregular cytoplasm structure
Internal membranes: Dark-stained

VvG stain

Myopathy
Many small immature muscle fibers

NADH stain

Myopathy
Many small immature muscle fibers dark-stained on NADH

NADH stain

Alkaline phosphatase stain

Myopathy
Scattered small immature muscle fibers with cytoplasm stained for alkaline phosphatase

ATPase pH 4.3 stain

Myopathy
Scattered small immature type 2C muscle fibers with intermediate-stained cytoplasm opn ATPase pH 4.3
Capillary pathology: ATPase stains large endomysial capillaries (Arrow)

ATPase pH 4.3 stain

Acid phosphatase stain

Myopathy: Small muscle fibers with abnormal cytoplasm
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers
Increased cytoplasm staining for acid phosphatase in granular pattern

Acid phosphatase stain

AMPDA stain

Myopathy: Small muscle fibers with abnormal cytoplasm
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers
AMPDA aggregates in muscle fiber cytoplasm

AMPDA stain

AMPDA stain

LC3 stain

Myopathy: Small muscle fibers with abnormal cytoplasm
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers
LC3 aggregates in muscle fiber cytoplasm

LC3 stain

LC3 stain

MHC Class I stain

Myopathy: Small muscle fibers with abnormal cytoplasm
Fiber sizes: Varied, Bimodal
Small, immature muscle fibers
MHC1 stains muscle fiber cytoplasm in irregular patterns
MHCI is only mildly up-regulated on the surface & cytoplasm of larger muscle fibers

MHC Class I stain

C_5b-9 stain

C_5b-9 stain
Present
In thick layer around muscle fiber surfaces
On endomysial connective tissue
Absent
No necrotic muscle fibers with cytoplasm staining