Clin Lab: MSK 1 Flashcards
(155 cards)
1
Q
Signs that are evidence of synovitis
A
swelling, warmth, tenderness
2
Q
burning” pain, or accompanied by numbness/tingling is more likely…
A
neuropathic pain
3
Q
Pain accompanied by weakness is more likely…
A
muscle or nerve issue
4
Q
Worse after inactivity is more likely…
A
inflammatory disorder (RA, psoriatic arthritis, lupus, etc)
5
Q
Worse with activity, better with rest is more likely…
A
osteoarthritis
(tends to be worse on one side)
6
Q
Symmetric joint involvement more likely…
A
systemic illness
7
Q
Duration of pain that is associated with a viral/reactive cause…
A
< 3weeks
8
Q
Duration of pain that is less likely to be a viral/reactive cause…
A
> 6 weeks
*think more long term chronic things like RA
9
Q
Symptoms more associated with systemic illness
A
- fever
- night sweats
- skin manifestations (lupus or scleroderma)
- adenopathy
10
Q
An younger/middle aged patient w/ joint pain think…
A
Lupus
11
Q
An older patient w/ joint pain think…
A
OA
12
Q
Monoarticular conditions
A
- OA
- Injury
- Septic arthritis*
- Crystal-induced (gout, CPPD)
- Neoplasms
13
Q
What is so important about septic arthritis?
A
It is a MEDICAL EMERGENCY
14
Q
Polyarticular w/ synovitis conditions
A
- Inflammatory joint dz
–> Infx (often viral)
–> Reactive arthritis
–> Psoriatic arthritis
–> RA
–> Crystal-induced
–> Systemic rheumatic illness**
–> Other systemic illness or malignancy (IBD)
–> Juvenile idiopathic arthritis
15
Q
What bacterial infx can causes polyarticular w/ synovitis?
A
- Lyme Dz
- Gonococcal
- Staph
16
Q
What viral infx can causes polyarticular w/ synovitis?
A
- Hep B or C
- Parvovirus
- Dengue virus
- Alphaviruses (chikungunya, equine encephalitis),
- HIV
- Mumps
- CMV
17
Q
List rheumatic illnesses that can cause polyarticular w/ synovitis.
A
- lupus
- vasculitis
- systemic sclerosis
- polymyositis
- dermatomyositis
18
Q
Polyarticular w/o synovitis conditions
A
- Fibromyalgia
- OA
- Neuropathic pain
- Depression
- Metabolic bone dz
- Endocrine disorder – hypothyroid, hyperparathyroid
- Plasma cell myeloma
19
Q
Workup for Monoarticular
A
- Imaging
- Arthrocentesis w/ analysis
- Labs (if needed)
- Synovial biopsy (RARE)
20
Q
Do you usually order imaging for monoarticular?
A
YES
we tend to get imaging when one joint is involved
21
Q
When would you want an arthrocentesis w/ synovial fluid analysis?
A
diagnose septic arthritis or gout
22
Q
Labs for Hemarthrosis w/o trauma
A
PT/INR, PTT, CBC
(checking for coag disorders like hemophilia)
23
Q
Labs for evidence of joint inflammation w/o infx (septic) or crystals
A
- ESR/CRP, CBC, CMP
- Testing for systemic rheumatic dz IF suspicion of that dz
- Testing for Lyme dz IF suspicion is high
24
Q
When would you do synovial biopsy?
A
- Fungal infx
- Sarcoidosis
- Lymphoma of the synovial joint
25
Workup for polyarticular w/ synovitis (red swollen joint)
- CBC, CMP, UA (uric acid crystals, Ca++ crystals)
- Arthrocentesis w/ synovial fluid analysis
- Labs based on clinical suspicion
--> ESR/CRP
--> Suspected systemic illness (RA, Lupus, Other systemic dz (IBD))
--> Viral antibodies (Hep B, C, Parvovirus B19)
--> Imaging – rarely needed
- Synovial biopsy - rare
26
Workup for Polyarticular w/o synovitis
- CMP
- TSH / PTH
- Imaging – x-ray
- Screening for depression
27
Arthrocentesis w/ Synovial Fluid Analysis Indications
- joint effusion/pain - dx of underlying pathology
- therapeutic
28
Arthrocentesis w/ Synovial Fluid Analysis Indications: example of underlying pathology
- Infx (Septic arthritis)
- Arthritis
- Crystalline arthritis (gout, pseudogout)
- Synovitis (inflammation)
- Neoplasm
29
Arthrocentesis w/ Synovial Fluid Analysis Indications: therapeutic
Injection of anti-inflammatory meds into the joint
30
What does a synovial fluid analysis include?
- Color & clarity
- Viscosity
These are ordered separately & must tell the lab
- Gram stain & culture
- Cell count & differential
- Crystal analysis
- Cytology
31
Synovial Fluid Analysis: NORMAL
Clarity:
Color:
Viscosity:
WBC/mm3:
PMNs% (neutrophils):
Clarity: Transparent
Color: Clear
Viscosity: High
WBC/mm3: < 200
PMNs% (neutrophils): < 25%
32
Synovial Fluid Analysis: Non-inflammatory
Clarity:
Color:
Viscosity:
WBC:
PMNs% (neutrophils):
Clarity: Translucent
Color: Yellow
Viscosity: High
WBC: 200 - 2,000
PMNs% (neutrophils): <25%
33
Synovial Fluid Analysis: Inflammatory
Clarity:
Color:
Viscosity:
WBC:
PMNs% (neutrophils):
Clarity: Translucent
Color: Yellow
Viscosity: Low
WBC: 2000 - 10,000 (up to 100,000)
PMNs% (neutrophils): >50%
34
Synovial Fluid Analysis: Septic
Clarity:
Color:
Viscosity:
WBC:
PMNs% (neutrophils):
Clarity: Opaque
Color: Dirty Yellow
Viscosity: Variable
WBC: >80,000
PMNs% (neutrophils): >75%
35
Synovial Fluid Analysis: Hemorrhagic
Clarity:
Color:
Viscosity:
WBC:
PMNs% (neutrophils):
Clarity: Bloody
Color: Red
Viscosity: Variable
WBC: 200 - 2,000
PMNs% (neutrophils): 50 - 75%
36
Arthrocentesis w/ Synovial Fluid Analysis Contraindications
- Artificial joint/joint replacement
- Lesions of skin overlying injection site
37
What is gout?
a build up uric acids crystals in the joint space
(very painful during gout attack)
38
Describe Tophaceous gout
pt has gout--> develop nodules called tophi--> can cause ulcerations (can occur anywhere on the body)
39
Gout testing:
1. Have to distinguish from septic (infected) joint
2. Crystal analysis of synovial fluid
monosodium urate crystals (look like needles)
--> “yellow” – negatively birefringent
3. Uric acid level
--> Hyperuricemia can cause crystalline arthropathy
--> Not sensitive or specific
--> Can be low/normal during a gout attack
40
Immediate Tx for Gout
Prednisone 1st line
NSAID (indomethacin) 2nd line
Pain meds
Colchicine 4th line
41
Prevention of Gout Meds
- Allopurinol
- Probenecid
- Colchicine
42
What does CPPD stand for?
Calcium Pyrophosphate Dihydrate Deposition
43
CPPD is also known as...
pseudogout
44
Testing for CPPD diagnosis
- Crystal analysis of synovial fluid
--> CPPD crystals (square – rectangular)
----> “Blue” – positively birefringent
- Chondrocalcinosis on imaging
--> Calcium deposits in cartilage
45
What is a physiological sign that can be seen & is indicative of RA?
Ulnar deviation of the fingers
46
What meds can help prevent ulnar deviation in RA?
DMARDs
47
Lab Diagnostics for RA
- ESR/CRP
- Rheumatoid factor (RF)
- Anti-citrullinated peptide antibodies (ACPA)
48
What will be seen on imaging in RA
joint erosions & deformities (seen in longstanding RA)
49
Indications to order an RF factor
Patients with clinical symptoms consistent with RA
50
Classic symptoms that make you think RA
Symmetrical joint pain, inflammation, fingers & knees, hurts more in the morning & better w/ movement
51
Is the RF a screening test?
NO
52
RF Explanation
- IgM Ab are made against the constant region of IgG Ab (antibodies attacking antibodies)
- Associated w/ RA, but non-specific --> (+) in other conditions (i.e., SLE, scleroderma)
~ 70-80% of pts w/ RA will be RF+
--> Some pts may become RF+ at later date
53
Is RF specific or non-specific?
non-specific
54
What are the two Anti-citrullinated Peptide Abs (ACPA)?
- Anticyclic-citrullinated Ab (anti-CCP)
- Anti-mutated citrullinated vimentin Ab (anti-MCV)
55
What is Citrulline?
an amino acid
56
How does Citrulline form?
it is a derivative of arginine; post-translation modification
57
Are the Anti-citrullinated Peptide Abs (ACPA) specific or non-specific?
More specific for RA
58
How is Anti-citrullinated Peptide Abs (ACPA) used in relation to RA?
biomarker for dz progression
59
How do you diagnose RA?
- Clinical Dx
- Scoring system used (labs are one component)
- (+) RF & (+) ACPA highly specific for RA
- Also need to rule out other systemic rheumatologic dz like SLE
60
What PE findings are consistent w/ psoriasis?
Pitting of nails, silvery plaques that bleed
61
Labs for Psoriatic arthritis
- No definitive labs
- Lab testing mostly done to rule out other arthritises
- Some assoc. w/ HLA-B27 genotype
--> HLA = human leukocyte antigen
62
Psoriatic arthritis imaging changes
- “pencil-in-cup”
--> aka “Symmetric bone erosions of the margin”
- Joint ankylosis (fusing) & joint destruction
63
Diagnostics for JIA
- Clinical dx
--> Childhood (average age 7yo)
64
How will a child present w/ suspected JIA?
Recurrent daily fever & polyarthritis
65
Expected Labs for JIA if done
- RF (-), ACPA (-)
- Elevated WBC & platelet counts
- Elevated ESR / CRP
- Very elevated ferritin
Most time it will go away after a few years
66
Prognosis of JIA
Most time it will go away after a few years
67
What is reactive arthritis?
- Arthropathy associated w/ other dz/disorders
--> GI infx, UTI, STI
68
Reactive arthritis Triad: Reiter's syndrome
- urethritis (dysuria)
- arthritis
- conjunctivitis (red eyes)
69
When does reactive arthritis usually occur?
1-4 weeks after triggering infx
70
Reactive arthritis workup
- Clinical dx
- Rarely will have evidence of current infx
- (+/-) elevated ESR/CRP
- Arthrocentesis, if done = inflammatory synovitis
- Tx: Steroids
71
How does lupus manifest throughout the body?
It is multi-system
72
Describe the various effects of Lupus on each system.
Skin
- Rash worse w/ sunshine
- Butterfly rash
- Spares nasolabial folds
MSK
- Arthritis
Bone marrow
Renal
- Lupus Nephritis
Cardiac/Pulm
- Pericarditis
- Chest pain better when leaning fwd
- Pericardial friction rub
- Diffuse ST seg elevation
73
SLE Testing
Testing for autoantibodies
- Anti-nuclear antibodies (ANA) – initial test
- Anti-double stranded DNA Ab
- Anti-Smith (anti-extractable nuclear antigen) Ab
- Anti-chromatin Ab
- Anti-phospholipid Ab (cardiolipin, lupus anticoagulant, beta-2-glycoprotein)
--> Anti-phospholipid syndrome (prone to clotting; need lifelong anticoag)
74
Anti-nuclear Antibodies pathophys
Many autoimmune rheumatologic diseases have autoantibodies against nucleic acid (DNA/RNA) antigens == anti-nuclear antibodies
75
Is Anti-nuclear antibodies (ANA) specific for any one dz?
NO
76
Explain ANA testing
Test = titer (dilutional conc)
Initial test is a specific dilution, usually (1:40).
- If (+), serial dilution is done until no longer p(+).
--> Highest dilution that is still (+) is reported
- Higher numbers = higher dz activity
- Test is done using indirect immunofluorescence
--> Pattern of fluorescence can help differentiate b/t diseases, but less specific
77
ANA Interpretation
- (-) ANA helps to rule out SLE (high sensitivity)
- Can be (+) in ppl w/o autoimmune disorder (~5% of adults) (low specificity)
- Not used for screening
- Once (+), will usually remain (+)
78
Anti-double stranded DNA Antibody Indications
Dx & follow-up of help support SLE
79
Anti-double stranded DNA Antibody Explanation
- High titers assoc. with SLE
- Low titers can be found in other dz (hep C)
- Levels change w/ dz activity
--> Monitor treatment
---> Diagnose flares
80
Anti-extractable Nuclear Antigen (Anti-Smith & anti-RNP) Indicaitons
dx of SLE & mixed CT dz (MCTD)
81
Anti-extractable Nuclear Antigen (Anti-Smith & anti-RNP) Explanation
Most common anti-ENA Ab are anti-Smith (SM) & anti-ribonucleoprotein (RNP)
- Anti-SM Ab is present in SLE & MCTD.
--> Present only 30% in SLE, 8% in MCTD.
- Anti-RNP present in 99%+ pts w/ MCTD
82
If I suspect a pt to have SLE, which Anti-extractable Nuclear Antigen would I order?
Anti-SM Ab
83
If I suspect a pt to have MCTD, which Anti-extractable Nuclear Antigen would I order?
Anti-RNP
84
Anti-Ro/SSA is primarily found in...
Sjogren’s syndrome
85
Anti-La/SSB is usually positive in....
Sjogren’s syndrome
86
When can Anti-Ro/SSA be positive?
- rare cases of ANA-negative SLE
--> Anti-La/SSB negative in SLE
87
Antichromatin Antibody indications
Important marker in renal dz in SLE
88
Antichromatin Antibody explanation
Levels show direct correlation w/ renal damage assoc. w/ SLE
Prognosis of renal damage
89
Anti-histone antibody indications
- Important marker in drug-induced lupus erythematosus
- Drug-induced SLE --> usually (-) for anti-double stranded DNA antibodies
90
Common meds related to anti-histone antibody
- isoniazid
- Hydralazine
- Procainamide
- Minocycline
- TNF blockers
- Anti-seizure meds
- Methyldopa
- Sulfasalazine
91
Why is Anti-phospholipid syndrome and SLE important?
If (+), it predisposes to unprovoked arterial/venous clot formation
92
Test all SLE patients for...
anti-phospholipid syndrome
93
What are the 3 things we look for in Anti-phospholipid syndrome.
- Anti-cardiolipin Ab
- anti-beta 2 glycoprotein
- lupus anticoagulant
only 1 (+) means (+) for syndrome
94
Sjögren’s Syndrome dz process:
- lymphocytic infiltration of the exocrine glands (salivary & lacrimal (tears))
Results in dry mouth (xerostomia) & dry eyes (keratoconjunctivitis sicca).
95
Two type of Sjögren’s Syndrome
Primary & secondary
96
Testing for Sjögren’s Syndrome
- Labs
- Schirmer Test
- Sialometry
- salivary gland biopsy
97
Describe the labs for Sjogren's Syndrome
- Anti-SS-A (anti-Ro) & Anti-SS-B (anti-La) are (+) in about 50% pts w/ primary Sjögren’s
- Can help to separate primary from secondary Sjogren’s
- Often ANA+ (>1:320) & RF+
- Elevated ESR/CRP
- CBC – anemia of Chronic Dz, leukopenia
- Low iron, high ferritin
- CMP – elevated PRO (polyclonal gammopathy)
--> A lot of different ab that are elevated
98
Describe Schirmer test
- Normal 15 mm in 5 mins
- Sjogren’s = 5mm
99
What is the most diagnostic test for Sjogren's Syndrome?
Salivary gland biopsy
100
Categories of Systemic sclerosis (Scleroderma)
- Limited systemic sclerosis (CREST syndrome)
- Diffuse systemic sclerosis
- Systemic sclerosis sine scleroderma
101
Describe diffuse systemic Sclerosis
- Xerostomia (Dry)
- interstitial lung dz
- pulm HTN
- Barrett's esophagus
- gastroparesis
- joint contractures
- uclers
- Raynaud's
Basically a lot of fibrosis going on
102
Diffuse systemic sclerosis Testing
- ANA+ in 90-95%
- Anti-topoisomerase I (anti-Scl-70) Ab
- Anti-U3 RNP (fibrillarin) Ab
- anti-RNA polymerase Ab
103
What is the antibody of choice to test in diffuse systemic sclerosis?
Anti-topoisomerase I (anti-Scl-70) Ab
104
What is the antibody is correlated w/ dz severity in diffuse systemic sclerosis?
anti-RNA polymerase Ab
105
What does CREST syndrome stand for?
- Calcinosis
- Raynaud phenomenon
- esophageal dysmotility
- Sclerodactyly
- Telangiectasia
106
Describe Calcinosis Cutis
Calcium deposits under the skin (everywhere)
can look like tophaceous gout but diffuse
107
What can you order to differentiate calcinosis cutis from tophaceous gout?
uric acid level
108
What is Raynaud Phenomenon?
When you go out in the cold something turns white, blue, red or mixed
109
Describe esophageal dysmotility
Dysfunction of the esophagus leading to dysphagia, heartburn, choking
110
Describe Sclerodactyly
- Resorption of the distal phalanx
- Swelling of fingers (sausage fingers), skin is shiny, contractures, loss distal joint
111
Describe telangiectasias
enlarged capillaries under the skin
"spider veins"
112
Testing for SSc (CREST)
- ANA+
- Anticentromere Ab
113
MCTD is most common in...
- women
- teenagers to 20s
114
MCTD S/S:
- Overlapping features of Sjogren’s, SLE, Systemic sclerosis (maybe GI problems), polymyositis
- Raynaud syndrome, diffuse hand swelling, polyarthralgias, lung dz (ILD, pulm HTN)
115
MCTD Testing
- ANA+
- U1 RNP+ (99%)
- RF+; anti-Sm & anti-dsDNA (-)
116
What is happening in Ankylosing spondylitis?
Calcification of ligaments & joints
117
Ankylosing Spondylitis S/S
stiffness & pain
118
Ankylosing spondylitis Testing
Imaging
- Fusion of SI joint, “bamboo spine”
Labs
- HLA-B27 testing
- (when patients has clinical picture but no proof on imaging)
119
What is polymyositis?
- autoimmune inflammation of skeletal muscle tissue
--> progressive proximal muscle **weakness**
120
What is dermatomyositis?
- muscle weakness plus skin involvement
--> can be due to occult malignancy & poss. interstitial lung dz
121
Which cancers should you check for in women w/ dermatomyositis?
breast uterine, cervical & GI cancers
122
Which cancers should you check for in men w/ dermatomyositis?
Prostate & GI cancer
123
Polymyositis hits which joints?
shoulders & hips
124
Testing for Myositis
- **Anti-Jo-1** (antihistidyl transfer synthase) Ab
- CPK (creatine kinase)
--> Elevated w/ inflammation or destruction of muscle cells
- Aldolase
--> Alt to CPK, often tested when CPK is (-)
- ESR/CRP – **usually not elevated**
125
Where does creatine kinase found?
found inside muscles
126
How is Polymyalgia rheumatica usually diagnosed?
largely a clinical dx
- proximal joint **pain/stiffness**
127
Testing for Polymyalgia rheumatica
- **Elevated ESR/CRP**
- **Assoc. w/ HLA-DR4**
- EMG
- MRI – muscle edema
- Muscle biopsy (definitive)
128
What is the definitive diagnostic test for polymyalgia rheumatica?
muscle biopsy
129
Polymyalgia rheumatica is often associated with...
giant cell arteritis (vasculitis)
(30-35%)
130
Is fibromyalgia inflammatory or non-inflammatory?
Non-inflammatory
131
Testing for fibromyalgia
- Clinical dx
- Rule out other dz
--> Hep C
--> Thyroid disorders
--> ESR/CRP
--> CBC
--> Only order testing for rheumatic dz if hx/PE or lab findings suggest it
132
What are Vasculitides?
Inflammation of BVs
133
List multiple types of Vasculitides
- Large vessels – Takayasu arteritis, giant cell arteritis
- Medium vessels – Polyarteritis nodosa, Kawasaki dz (peds)
Small vessels – ANCA-assoc. (polyangiitis), Immune complex (IgA, cryoglobulins)
134
Vasculitides labs is largely based on...
ruling out other dz
135
Labs to order for Vasculitides
- CBC, CMP, ESR/CRP
- Hepatitis panel (Hep B)
- Blood cultures
- decr complement levels
- ANA
136
How are Vasculitides definitely diagnosed?
Tissue biopsy or angiography
137
Giant cell arteritis affects...
large vessels
- aorta, carotids, extracranial branches
138
Who do we see giant cell arteritis in?
those >50 yo
139
Giant cell arteritis is assoc. w/...
polymyalgia rheumatica
140
Testing for giant cell arteritis
- Elevated ESR/CRP – usually very high
- Artery biopsy (often temporal artery)
141
Describe polyarteritis nodosa (PAN)
Rare, necrotizing vasculitis of medium-sized arteries
142
List medium-sized arteries affected by polyarteritis nodosa (PAN)
- Kidneys (not glomeruli)
- skin,
- joints
- muscles
- GI tract
143
Polyarteritis nodosa (PAN) is associated with...
Hep B & C
144
Polyarteritis nodosa (PAN) is seen in what population
Middle-aged adults
145
Polyarteritis nodosa (PAN) S/S
- systemic (fever, fatigue, etc)
- arthralgias & myalgias
- asymmetric sensory & motor issues in same area (multiple mononeuropathy)
- abd pain
- rapidly worsening HTN
- skin ulcers
146
Testing for Polyarteritis nodosa (PAN)
- Biopsy (focal)
- Hep B & Hep C
147
What is Granulomatosis w/ polyangiitis?
- Old name = Wegener’s granulomatosis
- Necrotizing vasculitis of small/medium vessels w/ granuloma formation
148
Granulomatosis w/ polyangiitis S/S
- Systemic sx
- Respiratory sx – upper (nosebleeds) & lower (hemoptysis)
- EENT sx (nasal congestion)
- Myalgias & arthralgias
- GN & AKI
- Multiple mononeuropathy
149
Testing for Granulomatosis w/ polyangiitis
- ESR/CRP
- UA (PROs & RBCs)
- CMP
- **c-ANCA & p-ANCA --- will be c-ANCA (+) to proteinase-3**
- Imaging (CT chest) - shows granulomas
- Biopsies
150
What is Eosinophilic granulomatosis with polyangiitis?
- Old name = Churg-Strauss syndrome
- Necrotizing vasculitis of small vessels w/ eosinophilic granulomas
151
Eosinophilic granulomatosis w/ polyangiitis S/S
- Adult onset asthma / allergies
- Systemic sx
- Skin – extensor surface nodules
- Nerve – multiple mononeuropathy
- MSK – arthralgias/myalgias
- Heart – HF/myocarditis
152
Testing for Eosinophilic granulomatosis w/ polyangiitis
- CBC – eosinophilia
- **ANCA – p-ANCA (+) for myeloperoxidase**
- ESR/CRP
- Echo
- Biopsy
153
What is Microscopic polyangiitis?
Necrotizing vasculitis of small vessels WITHOUT granulomas
154
Microscopic polyangiitis S/S
- Systemic sx
- GN & AKI
- Resp sx – lower (hemoptysis)
- Myalgias & arthralgias
155
Testing for Microscopic polyangiitis
- ANCA – p-ANCA (+) for myeloperoxidase
- ESR/CRP
- Imaging (CT chest)
- Biopsy
