SM 246a - Inflammatory Myopathies

Question 1

Perifascicular atrophy is a hallmark of

A: PM

B: DM

C: IBM

D: none of the above

Answer 1

B: DM

Question 2

Describe the presentation of necrotizing myopathy

Answer 2

• Little to no inflammation
• Lots of degeneration
• High creatine kinase
• Acute
• 2 major causes
  
  • Signal reduction particle
  • HMG-CoA Reductasse antibody
    
    • Associated with statin use

Question 3

What laboratory findings are consistent with polymyositis?

Answer 3

Elevated CK

Question 4

Ulcerated Gottran’s lesions + alopecia in a patient with dermatomyositis should prompt which next step in managemet?

Answer 4

Pulmonary work-up

High risk of interstitial lung disease

Question 5

A female patient presents with symmetric muscle weakness for the past 3 months. She reports trouble standing up from sitting and styling their hair.

A positive test for Anti-Jo-1 would make you concerned for what pathology?

Answer 5

This paitent most likly has polymyositis

Dermatomyositis also possible, depending on skin presentation (Heliotrope erupton, Gottron’s papules, calcinosis, photosensitivity, poikiloderma)

Anti-Jo-1 predicts Interstitial lung disease

Question 6

Which inflammatory myopathy(/ies) does this apply to?

More likely to affect distal muscles

Answer 6

Inclusion body myositis

Also affects proximal muscles, but polymyositis and dermatomyositis are much less likely to affect distal muscles

Question 7

Which inflammatory myopathy will have rimmed vacuoles on pathology?

What is inside these vacuoles?

Answer 7

Inclusion body myositis

Filled with beta-amyloid (the Alzheimer’s of muscle)

Question 8

Which inflammatory myopathy(/ies) does this apply to?

Rimmed vacuoles seen on biopsy

Answer 8

Inclusion body myositis

Question 9

Which inflammatory myopathy is associated with statin use?

Answer 9

Necrotizing myopathy

Question 10

What is the treatment for HMG CoA Reductase Necrotizing Myositis?

Answer 10

Immunotherapy

Question 11

List 4 inflammatory myopathies

Answer 11

• Polymyositis
• Dermatomyositis
• Incusion body myositis
• Necrotizing autoimmune myopathy

Question 12

When are patients with dermatomyositis at highest risk for malignancy?

Answer 12

First year of presentation

Remains elevated for 3 years

Question 13

Describe the laboratory findings associated with inclusion body myositis (IBM).

Answer 13

• Creatine kinase mildly elevated
• Anti-CN1A antibody may be present

Question 14

Other than treatment failure, worsening proximal weakness some months into the treatment of PM can be seen with

A: glucocorticoids

B: methotrexate

C: tacrolimus

D: rituximab

Answer 14

A: glucocorticoids

Question 15

Which antibodies are associated with ILD in patients with dermatomyositis?

Answer 15

• Anti-MDA5
  
  • Check this antibody if a patient has ulcerated Gottran’s papules
• Anti-Jo1

Question 16

Which necrotizing myopathy is more common in African-American women?

Answer 16

Signal Recognition Particle Myopathy

Question 17

Which inflammatory myopathy(/ies) does this apply to?

Typical patient is a man >50 y/o

Answer 17

Inclusion body myositis

Question 18

Inflammation and internalized nuclei can be seen on the biopsy of which inflammatory myopathy?

Answer 18

Polymyositis

Question 19

What is the treatment for IBM?

Answer 19

IVIg may work

Steroids will not work

Question 20

A patient with dermatomyositis is positive for Anti-TIF1-gamma antibodies.

What is the appropriate immediate next step?

Answer 20

• Check aldolase, creatine kinase
  
  • Evaluate muscle disease
• Pan-scan for malignancy
  
  • All adult-onset dermatomyositis is associated with malignancy, but Anti-TIF1-gamma very strongly

Question 21

An adult patient presents with proximal extensor inflammatory myopathy. They are having trouble brushing their hair and going up stairs.

Which connective tissue disorder do they most likely have?

Which labs should you order?

What are the most concerning association with this disease?

Answer 21

Dermatomyositis

Aldolase, creatine kinase

Malignancy (especially Anti-TIF-gamma), ILD (Anti-MDA5, Anti-Jo1)

Question 22

What is the recommended treatment for dermatomyositis?

Answer 22

• Corticosteroids
• AZA
• MTX
• IVIg
• Rituximab
• Cancer screening
• Pulmonary function tests

Question 23

Which inflammatory myopathy(/ies) does this apply to?

Affects proximal muscles

Answer 23

Polymyositis

Dermatomyositis

Question 24

Asymmetrical or distal weakness would suggest

A: PM

B: DM

C: IBM

D: any of the above

Answer 24

C: IBM

Question 25

What is the treatment for polymyositis?

Answer 25

* Systemic corticosterois * AZA * MTX * IVIG * Rituximab All of these methods take time to work; may be up to 6 months for maximal effect

Question 26

Describe the clinical presentation of polymyositis

Answer 26

* Symmetric * Proximal muscles affected more than distal * May have dysphagia * Insidious * Myalgias

Question 27

Malignancies are usually detected within ___ years of dermatomysitis onset, but ovarian cancer may be out to ___ years

Answer 27

Malignancies are usually detected within **_2**_ years of dermatomysitis onset, but ovarian cancer may be out to _**5_** years

Question 28

Describe the presentation of SRP myopathy

Answer 28

* Acute onset * Dysphagia * Raynaud's phenomenon * Myalgias * Minimal to no inflammation * More common in African Americans, women * Responds to immunotherapy

Question 29

Which inflammatory myopathy(/ies) does this apply to? **Patient presents with proximal muscle weakness**

Answer 29

Polymyositis Dermatomyositis

Question 30

Which of the following medications is most commonly associated with a necrotizing myopathy ## Footnote A: Azithromycin B: Simvastatin C: Gabapentin D: Tramadol

Answer 30

B: Simvastatin

Question 31

What antibody is most strongly associated with malignancy in adult dermatomyositis patients?

Answer 31

Anti-TIF1-gamma antibodies All dermatomyositis patients are at increased risk of malignancy, but especially patients positive for Anti-TIF1-gamma antibodies

Question 32

What will you see in a muscle biopsy of a patient with dermatomyositis?

Answer 32

Perifasicular atrophy Looks like fat smashed along the edges of muscles

Question 33

What will you see in a muscle biopsy of a patient with inclusion body myositis (IBM)?

Answer 33

* **Rimmed vacuoles** * Vacuoles contain **beta amyloid** * May need congo red to prove * Not a lot of inflammation

Question 34

What will you see in a muscle biopsy of a patient with polymyositis?

Answer 34

* Inflammation around normal muscle fibers * Scattered necrosis, degeneration, and regeneration * Internal nuclei * Variability of fiber size, but seldom hypertrophy

Question 35

Which muscles are often affected by inclusion body myositis (IBM)?

Answer 35

* Quads, wrist flexors, finger flexors * More likely to affect distal muscles than other inflammatory myopathies * Eventual dysphagia

Question 36

Describe the clinical presentation of inclusion body myositis

Answer 36

* M\>F * Older age of onset * **Distal** weakness * Difficulty shaving * Cannot grip golf club * Hard to walk * Getting up out of a seat is hard (quads) * Asymmetry * Progressive