JDM and Other Inflammatory Muscle Diseases Flashcards
1
Q
Peak age at onset of JDM
A
~7y
2
Q
T/F JDM is more common in girls
A
T
3
Q
Allele found to be potentially a major immunogenetic RF for JDM
A
HLA DRB1*0301
4
Q
Vaccine reported to be associated with development of JDM within 6 months of flare
A
HPV
5
Q
Cells that play a key role in the pathogenesis of JDM
A
pDCs
6
Q
Activity of this cytokine is higher in JDM than healthy individuals
A
IFN-a
7
Q
Mean duration from symptom onset to diagnosis of JDM
A
3-7months
8
Q
Descriptors of muscle weakness in JDM
A
Symmetrical, more severely affects limb girdle musculature, anterior neck flexors, and trunk muscles
9
Q
Physical manifestation (sign) that reflects proximal lower extremity weakness
A
Gower’s sign
10
Q
Physical manifestation (sign) that reflects gluteal muscle weakness
A
Trendelenburg sign
11
Q
T/F Arthritis of JDM is nonerosive and non-deforming
A
T
12
Q
MC manifestations of pediatric JDM
A
Fatigue, muscle weakness, heliotrope rash, gottron papules
13
Q
T/F Reduced nailfold capillary density is characteristic of JDM
A
T
14
Q
T/F Normal nailfold capillary density in children with JDM is associated with shorter duration of untreated disease and lower skin disease activity
A
T
15
Q
T/F Nailfold capillary is associated with skin and muscle disease activity in JDM
A
T
16
Q
T/F Nailfold capillary can be used to track clinical improvement over time after treatment of JDM
A
T
17
Q
T/F Calcinosis is rare as a presentation of JDM
A
T, develops during the disease course and is thought to be a scarring response
18
Q
Consequence of JDM that results from insulin resistance secondary to muscle inflammation and damage
A
Lipoatrophy
19
Q
T/F Cardiac involvement is common in JDM
A
F, rare
20
Q
T/F ECG and echo should only be done among patients with JDM who are at risk for cardiac disease
A
F, the SHARE initiative recommends to do these in all patients with JDM at diagnosis
21
Q
T/F ILD is common in JDM
A
F, rare but one of the most serious complications
22
Q
T/F PFTs are recommended for all patients at diagnosis of JDM
A
T
23
Q
T/F ILD in JDM usually presents with unilateral lesion on the upper lobe
A
F, bilateral, lower lobe
24
Q
T/F In any patient with renal disease and features if JDM, a diagnosis of SLE is more likely
A
T
25
T/F Most case described as juvenile IIM with renal involvement require additional immunosuppressive agent/s for the renal involvement
F, most respond to conventional treatment for IIM
26
Accounts for 80% of all children with IIM
JDM
27
Alleles identified as protective factors, seen less frequently in Caucasians with JDM
HLA DQA1*0202, *0101, and *0102
28
Non-HLA-associated genes implicated in the pathogenesis of JDM
TNF-a and IL-1 receptor antagonist
29
TNF-a allele associated with a more prolonged disease course (≥36 months) and calcification in JDM, as it synthesizes more TNF-a, which may be associated with persistent immune activation
TNF-a-308A
30
TNF-a allele associated with small-vessel occlusion and increased concentration of circulating TSP-1, which enhances proliferation and migration of vascular smooth muscle cells
TNF-a-308A
31
IL-1 receptor antagonist gene allele identified as a risk factor for juvenile IIM in Caucasians but not in African Americans
A1 allele
32
IL-1 receptor antagonist gene allele identified as a possible risk factor for juvenile IIM in African Americans
A3 allele
33
Environmental factors reported to be related to disease flare in JDM
1) Unusual sun exposure
2) NSAID use within the preceding 6 months
3) Anti-htn and psychiatric medications
4) HPV vaccine within 6 months of flare
5) Infection
34
The main Type 1 interferon-producing cells
pDCs
35
Cytokines implicated in the pathophysiology of JDM
1) Type 1 IFN (IFN-a)
2) Type 2 IFN (IFN-γ)
36
Type 2 IFN is predominantly produced by
NK cells and activated T cells
37
JDM: MC Constitutional manifestation
Fatigue
38
JDM: MC MSK manifestation
Muscle weakness
39
JDM: MC Cutaneous manifestation
Heliotrope rash, Gottron papules
40
Normal nail fold capillary density values
7-11 capillaries/mm
41
Nailfold capillary changes seen in JDM
1) Capillary dropout
2) Enlarged and elongated capillaries (giant capillaries)
3) Bushy capillaries
4) Areas of hemorrhage
42
Calcinosis in JDM tends to be present in what areas
Pressure points
43
Can be detected in the serum of JDM patients early in the disease course regardless of symptoms
KL-6
44
Antibodies associated with ILD in JDM
MDA5
45
Diagnosis of JDM is confirmed using
Bohan and Peter criteria 1975
46
Bohan and Peter Criteria for JDM
DEFINITE JDM
Pathognomonic rash (heliotrope/gottron) + 3/4
1. Proximal muscle weakness
2. Elevated muscle nz
3. EMG changes of chronic inflammatory myositis
4. Histopath changes of inflammatory myositis
PROBABLE JDM
Pathognomonic rash + 2/4
47
EULAR/ACR JDM classification score that corresponds to definite IIM
≥7.5 w/o muscle biopsy
≥8.7 with muscle biopsy
48
EULAR/ACR JDM classification score that corresponds to definite IIM
5.5 to <7.5 w/o muscle biopsy
6.7 to <8.7 with muscle biopsy
49
EULAR/ACR JDM classification score that corresponds to possible IIM
<5.3 w/o muscle biopsy
<6.5 with muscle biopsy
50
Distinguishes juvenile from adult IIM
Age at onset of symptoms <18
51
T/F of JDM: A muscle biopsy is NOT required for a definite diagnosis if the pathognomonic skin rash is present
T
52
T/F Serum muscle enzymes may be normal at presentation even in patients with active JDM
T
53
T/F Levels of elevated muscle enzymes at JDM onset correlate with disease outcome
F
54
T/F ESR and CRP may be normal in patients with active JDM
T
55
Biomarkers proposed to distinguish active disease vs remission in JDM
Galectin-9 and CXCL10
56
Group of autoantibodies present specifically in patients with IIM
MSA
57
Group of antibodies that occur in patients with other autoimmune conditions that are associated with myositis
MAA
58
MSAs
1) Anti-TIF-1γ (anti-p155/140)
2) Anti-NXP2 (formerly anti-MJ)
3) Anti-MDA5
4) Anti-Mi-2
5) Anti-SRP
6) Anti-tRNA synthetase
7) Anti-HMGCR
8) Anti-SAE
59
MAAs
1) Anti-Ro
2) Anti-RNP
3) Anti-PM-Scl
60
MSAs: Autoantibodies associated with malignancy in ADULTS
Anti-TIF-1γ
61
MSAs: Autoantibodies associated with greater muscle weakness in children
Anti-TIF-1γ
Anti-NXP2
Anti-SRP
62
MSAs: Autoantibodies associated with younger age at onset
Anti-NXP2 (formerly anti-MJ)
63
MSAs: May predict development of ILD
Anti-MDA5
64
MSAs: Autoantibodies associated with classical JDM phenotype
Anti-Mi-2
65
MSAs: Autoantibodies associated with high ANA titers
Anti-Mi-2
66
MSAs: Autoantibodies associated with cardiac abnormalities
Anti-SRP
67
MSAs: Autoantibodies associated with chronic continuous disease course
Anti-SRP
68
MSAs: Autoantibodies associated with older age at onset
Anti-tRNA synthetase
69
MSAs: Autoantibodies associated with more insidious onset of disease
Anti-tRNA synthetase
70
MSAs: Autoantibodies associated with only a partial response to immunosuppressive meds
Anti-HMGCR
71
MSAs: Autoantibodies associated with disease that seems to be IVIg responsive
Anti-HMGCR
72
MC MSA in JDM
Anti-TIF-1γ (anti-p155/140)
73
MAAs: Associated with good prognosis in myositis
Anti-U1-snRNPs
74
MSAs: Severe cutaneous disease
Anti-TIF-1γ (anti-p155/140)
75
MSAs: Predicts poor prognosis
Anti-MJ
76
MSAs: Milder muscle disease (low CK levels)
Anti-MDA5
77
MSAs: Better prognosis
Anti-Mi-2
78
MSAs: Initially myopathic disease in adult DM
Anti-SAE
79
MSAs: Very high CK levels
Anti-SRP
80
Characteristic BUT nonspecific findings of inflammatory myopathy on EMG
1) Increased spontaneous and insertional activity (as evidenced by fibrillation potentials and positive sharp waves)
2) Low amplitude, short duration, polyphasic motor unit action potentials
3) Early recruitment
81
Muscle biopsy should ALWAYS be considered in investigating for JDM when
1) Absence of skin rash
2) Atypical presentation
82
Typical muscle biopsy in dermatomyositis
1) Perifascicular atrophy
2) Muscle fiber size variation
3) Muscle degeneration and degeneration
4) Centralization of nuclei
5) Vasculopathy
6) Swelling of capillary endothelium
7) Perivascular infiltration of, primarily, pDCs, B cells, CD4+ T cells, and macrophages
83
Electron microscopic findings in dermatomyositis
Tubuloreticular inclusions
84
IHC staining findings in JDM
1) Increased MHC class I
2) Increased IFN-α/β inducible protein myxovirus resistance A (MxA)
85
IHC staining finding that correlates with disease activity
Increased MxA
86
4 domains that make up the scoring tool for histological abnormalities in JDM developed by the Int'l JDM Biopsy Consensus Group
1) Inflammatory
2) Vascular
3) Muscle fiber
4) Connective tissue
*Includes overall score of severity using a 10-cm visual analog scale
87
The tool developed by the Int'l JDM Biopsy Consensus Group has been used for what muscles
Biceps and quadriceps muscle biopsies
88
T/F The tool developed by the Int'l JDM Biopsy Consensus Group has been evaluated for other IIMs
F
89
2 most reliable domains in the tool developed by the Int'l JDM Biopsy Consensus Group that correlate with disease activity
1) Inflammatory
2) Muscle fiber
90
T/F Pathological findings in JDM muscle biopsy can be used to determine prognosis
T
91
Finding in JDM pretreatment muscle biopsy that predicts a chronic disease course
Extensive myopathic changes and central nuclei without basophilia
92
Finding in JDM pretreatment muscle biopsy that predicts a chronic disease course WITH ULCERATION
Severe arteriopathic changes
Positive arterial direct IF
Foci of severe capillary loss or endomysial fibrosis
Muscle infarcts
93
T/F Plain radiographs are generally sufficient to determine extent of calcinosis in JDM
T
94
Diagnostic modality for JDM that is preferred in cases where MRI or muscle biopsy is not possible
Muscle ultrasonography
95
UTZ findings in JDM
1) Increased muscle echogenicity
2) Calcification seen as echogenic foci with posterior acoustic shadowing
96
T/F Muscle UTZ in JDM correlates well with disease activity
T
97
T/F MRI IV contrast material is NOT necessary to evaluate muscle disease
T
98
Appearance of IIM in STIR sequences
Increased signal intensity (reflects edema)
99
Imaging modality for JDM that detects muscle atrophy and fatty infiltration in the presence of chronic disease
T1-weighted sequences
100
An effective imaging modality to assess whether patient has JDM flare or not when the clinical assessment and lab parameters are equivocal
MRI
101
JDM MRI Score (JIS) range
0 (normal) to 100 (severe)
102
Ddx for JDM: Characteristic rash of JDM without evidence of muscle involvement
Amyopathic Dermatomyositis
103
For amyopathic JDM, characteristic rash should have bee present for at least how long?
6 months
104
Ddx for JDM: Patients with classic JDM rash without clinical weakness but who may have evidence of subclinical myositis based on muscle nz, EMG, MRI, or muscle biopsy
Hypomyopathic dermatomyositis
105
Only ___% of total JDM cases are myopathic dermatomyositis on further investigations
4
106
About ___% of patients with hypomyopathis DM evolve into classic JDM
25
107
Ddx for JDM: Muscle weakness in the absence of characteristic skin lesions
Juvenile polymyositis
