Rheumatology Diagnostics Flashcards
1
Q
What are the diagnostic tests available for rheumatology?
A
- blood tests
- joint (synovial) fluid analysis
- imaging tests
2
Q
What imaging is available for rheumatology?
A
- x-rays
- US
- CT
- MRI
3
Q
What blood tests are done for rheumatology?
A
- FBC
- U+Es
- LFTs
- Bone profile
- ESR
- CRP
4
Q
What are the main types of arthritis?
A
- osteoarthritis
- inflammatory arthritis
- septic arthritis
5
Q
What would you see on an FBC with inflammatory arthritis?
A
Hb = anaemia or normal MCV = normal WCC = normal Platelet = normal/raised
6
Q
What would you see on an FBC with osteoarthritis?
A
Hb = normal MCV = normal WCC = normal Platelet = normal
7
Q
What would you see on an FBC with septic arthritis?
A
Hb = normal MCV = normal WCC = increased/leucocytosis Platelet = normal/increased
8
Q
What does a higher creatinine?
A
worse renal clearance (indicating kidneys problem)
9
Q
What is the effect of systemic lupus erythematous on the kidneys?
A
lupus nephritiis
10
Q
What is the effect of vasculitis on the kidneys?
A
nephritis
11
Q
What is the effect of chronic inflammation on the kidneys?
A
- high levels of serum amyloid A (SAA) protein
- SAA deposits in organs (AA amyloidosis)
12
Q
What does a low albumin reflect?
A
- problem of synthesis (in liver)
- problem of leak from kidney (eg in lupus nephritis)
13
Q
What is the effect of Disease Modifying anti-rheumatic drugs on the liver?
A
can cause liver damage
- pts on methotrexate need regular blood tests (every 8 weeks)
14
Q
What is tested in a bone profile?
A
- Calcium
- Phosphate
- Alkaline phosphatase
15
Q
What is Paget’s disease?
A
an abnormality of high bone turnover
16
Q
What are the clinical features of Paget’s disease?
A
- bone pain
- excessive pain growth
- fracture in areas of abnormal bone
17
Q
What can be seen in a bone profile if the patient has Paget’s disease?
A
raised ALP
18
Q
What is osteomalacia?
A
soft bones due to vitamin D deficiency
19
Q
How does osteomalacia present on a bone profile?
A
ALP: normal or raised
Ca and PO4: normal or low
20
Q
What is osteoporosis?
A
low bone density
21
Q
How does osteoporosis present on a bone profile?
A
Calcium, phosphate and ALP normal
22
Q
What can cause a raised ESR?
A
- inflammation
- elevated immunoglobulin level
- paraprotein (myeloma)
- anaemia
- increasing age
23
Q
How does SLE present on an inflammation profile?
A
ESR: high
CRP: normal
24
Q
When can CRP be high in SLE?
A
- significant synovitis
- inflammatory pleural/pericardial effusion
25
What should be done if there is an elevated CRP in lupus?
have a low index of suspicion for infection
26
What are the 2 types of antibodies found in the bloods of RA patients?
- rheumatoid factor
| - cyclic citrullinated peptides
27
What is rheumatoid factor?
Antibodies that recognize the Fc portion of IgG as their target antigen typically IgM antibodies i.e. IgM anti-IgG antibody
28
How common is rheumatoid factor?
- positive in 70% at disease onset
| - further 10-15% become positive over the first 2 years of diagnosis
29
What are cyclic citrullinated peptides?
- more specific than RF
| - associated with a worse prognosis
30
What are anti-nuclear antibodies?
antibodies directed at the nuclear component of the cell
31
What is known about non-specific anti-nuclear antibodies?
- Relatively common in general healthy population at low titre (level)
- Prevalence of ANA increases with age
- Sometimes transiently positive following infection
32
What is the use of anti-nuclear antibodies in rheumatology?
high titre ANA with correct clinical features can indicate an autoimmune connective tissue disease
33
What can a high ANA level with clinical features suggest?
- SLE
- scleroderma
- Sjogern's syndrome
34
What are the clinical features of SLE?
- Arthritis
- Skin rash
- Mouth ulcers
- Kidney disease
- Haematological
- Pleural effusion
- Pericardial effusion
35
What are the clinical features of Scleroderma?
- Vasculopathy (esp. Raynaud’s phenomenon)
- Skin thickening
- Organ fibrosis
36
What are the clinical features of Polymyositis?
- Muscle inflammation
- Weakness
- High CK
37
What are the clinical features of Sjorgen's syndrome?
- Dry eyes
- Dry mouth
- Extra-articular features
38
How is ANA reported?
as a maximal dilution at which it is still detectable
39
What does a negative ANA test exclude?
SLE
40
What does a positive ANA test suggest?
suggestive of SLE if clinical and lab features support
41
What other tests should be ordered if ANA is positive?
- ENA (extractable nuclear antigens)
- double stranded (dsDNA) antibodies
- complement levels C3 and C4
42
What is tested for in an ENA panel?
- Ro
- La
- RNP
- Smith
- Jo-1
43
What does a positive Ro antibody test suggest?
Lupus or Sjogrens syndrome
44
What does a positive La antibody test suggest?
Lupus or Sjogrens syndrome
45
What does a positive RNP antibody test suggest?
Lupus or mixed connective tissue disease
46
What does a positive Smith antibody test suggest?
Lupus
47
What does a positive Jo-1 antibody test suggest?
Polymyositis
48
What does a positive dsDNA antibody test suggest?
- highly specific for lupus
- associated with renal involvement
- useful for tracking lupus activity over time
49
What does reduced complement levels of C3 and C4 suggest?
active lupus
50
How do you do a synovial fluid analysis?
obtained by aspirating fluid from a joint
51
What are the indications for joint aspiration?
- Diagnostic: to obtain synovial fluid for analysis
| - Therapeutic: to relieve symptoms (+/- concurrent steroid injection)
52
What are the 2 main diagnostic uses of aspiration?
- suspected arthritis
(send for MC+S, identification of causing organism, sensitivities for ABx)
- diagnosing crystal arthritis
53
What is the gold standard tests to diagnose suspected septic arthritis?
aspiration for a synovial fluid analysis
54
How does a diagnosis of crystal arthritis occur?
- aspirating fluid from the affected joint
| - examination under a microscope using a polarised light
55
How does gout present in a synovial fluid arthritis?
needle shaped crystals with negative birefringence
56
How does pseudogout present in a synovial fluid arthritis?
rhomboid shaped crystals with positive birefringence
57
How does a synovial fluid culture present in septic arthritis?
positive
58
How does a synovial fluid culture present in reactive arthritis?
sterile
59
Is ABx therapy recommended in septic arthritis?
yes
60
Is ABx therapy recommended in reactive arthritis?
no
61
Is joint lavage recommended in septic arthritis?
yes - in large joints
62
Is joint lavage recommended in reactive arthritis?
no
63
What is the first line imaging in rheumatology?
x-rays
64
Why are MRIs used in rheumatology?
- Best visualization of soft tissue structures like tendons and ligaments
- Best for spinal imaging: can see spinal cord and exiting nerve roots
- but, Expensive and time-consuming
65
Why are US used in rheumatology?
- can visualize soft tissue structures.
| - Good for smaller joints, less good for deep/large joints like knee or hip
66
What are the XR features of osteoarthritis?
- joint space narrowing
- subchondral bony sclerosis
- osteophytes
- subchondral cysts
67
What causes the joint space narrowing on a XR of osteoarthritis?
loss of articular cartilage leading to bone to bone contact
68
What are osteophytes?
bone spurs
69
What features of rheumatoid arthritis can be seen on a XR?
- soft tissue swelling
- peri-articular osteopenia
- bony erosions
- joint space narrowing
70
When do bony erosions occur?
- only in established disease
| - aim is to treat before formation
71
Why can US be better than XR in rheumatoid arthritis?
better to detect synovitis
72
What features of rheumatoid arthritis can be seen on a US?
- Synovial hypertrophy (thickening)
- Increased blood flow (seen as doppler signal)
- May detect erosions not seen on plain X-ray
73
When does joint space narrowing occur in oestoarthritis?
primary abnormality
74
When does joint space narrowing occur in rheumatoid arthritis?
secondary damage due to synovitis
75
What are Heberden's nodes?
osteophytes at the distal inter-phalangeal joints
76
What are Bouchard's nodes?
osteophytes at the proximal inter-phalangeal joints
77
What is a common early radioactive sign of inflammatory arthritis?
juxta-articular osteopenia
78
Where do bony erosions tend to occur?
the margins of the joint where the synovium is in direct contact with bone
79
What are the radiographic features of gout?
juxta-articular 'rat bite' erosions at the metaphalangeal joint of the big toe
80
What are the radiographic features of psoriatic arthritis?
- asymmetrical pattern of joint involvement
- erosions of interphalangeal joints
- MCPJs not affected
81
What investigations should be done for suspected SLE?
- ESR, CRP
- haematology
- renal function tests
- antibodies and complement
- clotting
82
What would be seen on a haematology screen for SLE?
- haemolytic anaemia
- lymphopenia
- thrombocytopenia
83
What renal function tests should be done in SLE?
- uP:CR
| - albumin
84
What would be included immunological screen for SLE?
- anti-nuclear antibodies
- anti-double-stranded DNA antibodies
- complement consumption
85
What would be seen on a clotting screen for SLE?
- anti-phospholipid antibodies
- lupus anticoagulant
- anti-cardiolipin antibodies
86
What would be seen immunological screen for SLE?
- low complement C3 and C4
| - high levels of anti-ds-DNA antibodies
87
What are the aims when treating SLE?
remission or low disease activity and flare prevention
88
What medication is recommended in all patients with lupus?
hydroxychloroquine
89
What treatment should be minimised/withdrawn for SLE?
maintenance treatment glucocorticoids
90
What can help reduce the usage of maintenance treatment glucocorticoids?
the appropriate initiation of immunomodulatory agents (methotrexate, azathioprine, mycophenolate)
91
What treatment is used in persistently active or severe SLE?
- cyclophosphamide
| - B cell targeted therapies (rituximab and belimumab)
92
What should patients with SLE be assessed for?
- anti-phospholipid antibody status
| - infectious and CVD risk profile
93
What is Sjögren's syndrome?
autoimmune exocrinopathy:
| - lymphocytic infiltration of exocrine glands and occasionally other organs (extra-glandular involvement)
94
How does Sjögren's syndrome present?
- xerophthalmia (dry eyes)
- xerostomia (dry mouth)
- parotid gland enlargement
95
What are the most common extra-glandular manifestations in Sjögren's syndrome?
- non-erosive arthritis
| - Raynaud's phenomena
96
What is meant by secondary Sjögren's syndrome?
if it occurs in the context of another connective tissue disorder
97
What tests can be done if Sjögren's syndrome is suspected?
- salivary gland biopsy
| - Schimer's test
98
What will a salivary gland biopsy show in Sjögren's syndrome?
- lymphocytic infiltration
- predominantly CD4 helper T cells
- less so: B lymphocytes
99
What will a salivary Schimer's test show in Sjögren's syndrome?
<5mm after 5 minutes
100
What is Schimer's test?
test to assess tear production
- filter paper under the lower eyelid
- extent of wetness measured after 5 minutes
- abnormal is <5mm after 5 minutes
101
What is inflammatory muscle disease?
Proximal muscle weakness due to autoimmune-mediated inflammation either with (dermatomyositis) or without (polymyositis) a rash
102
What are the skin changes seen in dermatomyositis?
- lilac-coloured (heliotrope) rash on eyelids, malar region and naso-labial folds
- red/purple flat/raised lesions on knuckles (Gottron's papules)
- subcutaneous calcinosis
- fissuring and cracking of the skin (mechanic's hands)
103
What is associated with inflammatory muscle disease?
- malignancy (10-15%)
| - pulmonary fibrosis
104
What is systemic sclerosis?
- thickened skin with raynaud's phenomenon
- dermal fibrosis
- cutaneous calcinosis
- telangiectasia
105
What are the 2 different types of systemic sclerosis?
- limited
| - diffuse
106
What is seen in limited systemic sclerosis?
- fibrotic skin, hands, forearms and face
- anticentromere antibodies
- pulmonary hypertension
- Hx of raynaud's phenomenon - CREST
107
What dose CREST stand for?
- Calcinosis
- Raynaud's phenomenon
- Esophageal dysmotility
- `Sclerodactylly
- Telangiectasia
108
What is seen in diffuse systemic sclerosis?
- Fibrotic skin proximal to elbows or knees (excluding face and neck)
- Anti-topoisomerase-1 (anti-Scl-70) antibodies
- Pulmonary fibrosis, renal (thrombotic microangiopathy) involvement
- Short history of Raynaud’s phenomenon
109
What is overlap syndrome?
When features of more than 1 connective tissue disorder are present e.g. SLE and inflammatory muscle disease we can use the term overlap syndrome
110
What tests are done and seen in suspected inflammatory muscle disaster/
- high CPK
- abnormal electromyography
- abnormal muscle biopsy
111
What would be seen in abnormal muscle biopsy?
polymyositis:
- CD8 T cells
dermatomyositis:
- CD4 T cells in addition to B cells
112
When is the term undifferentiated connective tissue disorder?
When incomplete features of a connective tissue disease are present
113
What antibody can be used to identify different connective tissue disorders?
Anti-U1-RNP antibody
114
What are the key auto-antibodies in diffuse systemic sclerosis?
Anti-Scl-70 antibody
| also termed antibodies to topoisomerase-1
115
What are the key auto-antibodies in limited systemic sclerosis?
Anti-tRNA transferase antibodies
| E.g. histidyl transferase (also termed anti-Jo-1 antibodies)
116
What are the key auto-antibodies in dermato/polymyositis
Anti-tRNA transferase antibodies
| E.g. histidyl transferase (also termed anti-Jo-1 antibodies)
117
What are the key auto-antibodies in Sjören's syndrome?
-No unique antibodies but typically see:
- Antinuclear antibodies
- Anti-Ro and anti-La antibodies
Rheumatoid factor
118
What are the key auto-antibodies in mixed connective tissue syndrome?
Anti-U1-RNP antibodies
