Rheumatology - ix Flashcards

1
Q

OA ix

A

XRAY LOSS
• Loss of joint space/ Non-uniform joint space narrowing
• Osteophytes
• Subchondral sclerosis/Subchondral bony sclerosis
• Subchondral cysts/Bone cysts

• Joint aspirate
Straw coloured fluid
Increased viscosity

• Normal blood tests

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2
Q

RA ix

A

Bloods
• Rheumatoid factor
IgM antibody that targets other IgG antibodies
Most sensitive
• Anti-cyclic citrullinated peptide antibodies (anti CCP)
Most specific
• ACD, increased ESR/CRP, low albumin

Radiology (first one most common, then decreasing order)

  • uniform joint space narrowing
  • soft tissue swelling
  • juxta-articular erosions
  • joint subluxation
  • osteopenia
  • Joint erosions at joint margins
  • joint deformity + destruction
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3
Q

Amyoidosis ix

A

• Tissue biopsy
o Congo red stain – pink in real life, apple-green birefringence when viewed under polarised light

• Immuo-electro microscopy
o Amyloids - Fibrillar, rigid, non-branching

• Mass spectrometry
o Gold standard for amyloid typing
o Provides analysis of amyloid protein composition

• 24h urine collection
o >1g/24h urinary albumin - renal involvement in amyloidosis
o >3g/24h urinary albumin - nephrotic syndrome

  • Increased ESR, N CRP
  • Blood film - Howell Jolly bodies
  • Hepatic amyloidosis - low albumin, increased ALP
  • Renal amyloidosis - low albumin, N creatinine
AL amyloidosis (primary) - caused by plasma cell disorders
•	Serum immunofixation + Urine immunofixation
o	Presence of monoclonal protein (in immunoglobulin light chain amyloidosis)

• Immunoglobulin free light chain assay
o Abnormal kappa to lambda ratio

• Bone marrow biopsy
o Clonal plasma cells (gamma > kappa)

The finding of light chain protein in the urine is suggestive of multiple myeloma + amyloidosis (have in mind that amyloidosis is caused by multiple myeloma)

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4
Q

Ankylosing spondyltis ix

A

• Pelvic XR
o Sacroiliitis
o A dx of established AS requires definitive evidence of sacroiliitis on XR

• Cervical spine, thoracic spine, lumbar spine XR
o Erosion
o Joint space narrowing
o Squaring sclerosis
o Syndesmophyes
o Ossification of spinal ligaments
o Bamboo spine (complete fusion of the vertebral column)
o Romanus lesions - erosion of the corners of the vertebral bodies

• MRI
o Useful in identifying early sacroiliitis before XR changes are apparent
o XR changes take may years to develop and represent established damage

  • HLA-B27 – not diagnostic, genetic testing to help confirm the dx
  • US – to confirm/quantify the extent of enthesis

• Schober’s test
o Patient in a standing position
o Mark L5
o Then mark 5 cm below and 10 cm above L5 (total distance of 15 cm)
o Ask patient to touch his/her toes while keeping the knees straight
o Distance of the two points must increase by at least 5 cm (with the total distance greater than 20 cm)
o If not –> restricted lumbar flexion

Bloods may show - ACD, raised ESR, CRP

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5
Q

Diagnostic criteria for anlylosing spondylitis (modified New York criteria)

A

Definite AS – radiological criterion + at least 1 clinical criterion

Probable AS – 3 clinical criteria // radiological criterion w no clinical criteria

Clinical criteria
• Low back pain >3 months [Improved by exercise, not relieved by rest]
• Limitation of lumbar spine motion in both sagittal + frontal planes
• Limitation of chest expansion relative to normal values for age + sex

Radiological criterion
• Sacroiliitis on X-ray

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6
Q

Reactive arthritis ix

A

Bloods
• HLA B-27
• ESR + CRP high
• Normocytic anaemia, mild leucocytosis, thrombocytosis

• Synovial fluid examination
WCC
Required to rule out septic/crystalline arthritis

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7
Q

Septic arthritis ix

A
•	Joint aspirate 
o	Before abx
o	Turbid yellow
o	Low viscosity
o	Increased WCC (neutrophils >90%)
  • MCS of joint aspirate
  • XR – Joint space narrowing due to cartilage destruction
  • US – can detect early effusions + guide joint aspiration
  • CT+ MRI – periarticular abscesses, joint effusions, osteomyelitis
  • Bloods - Increased WCC, CRP
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8
Q

Gout ix

A

• increased serum urate levels
Should be obtained at least 2 weeks after the attack resolves as it may be falsely low or normal during the attack

• Synovial fluid analysis + Electron microscopy
o Monosodium urate crystals in or outside the cell
o Sharp, needle-like form
o Negatively birefringent under polarised light (yellow under parallel light, blue under perpendicular light)
o Raised WBC count with neutrophil dominance
o Low viscosity

• Gram stain + culture – to exclude infection

•	XR or CT for chronic gout 
o	Crystal deposits
o	Periarticular erosions ("rat-bite" erosions)
   sclerotic margins
   overhanging edges
o	Punched out periarticular erosions

• Bloods
o Raised WCC (neutrophil dominance)
o Raised CRP
o Uric acid after 4-6 weeks

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9
Q

Pseudogout ix

A

• Synovial fluid analysis + Electron microscopy
o Calcium pyrophosphate crystals in or outside the cell
o Rhomboid or rod-shaped appearance
o Weakly positively birefringent under polarised light (blue under parallel light, yellow under perpendicular light)
o Raised WBC count with neutrophil dominance
o Low viscosity

• Imaging
o Chondrocalcinosis – cartilage calcification

• Screening for
o Hyperparathyroidism (serum calcium, serum PTH)
o Hypothyroidism
o Hypomagnesemia (serum magnesium)
o Hypophosphatasia (serum ALP)
o Hemochromatosis (iron studies – serum ferritin, iron, TIBC)

• Bloods
o Raised WCC (neutrophil dominance)
o Raised CRP

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10
Q

Osteomyelitis ix

A

Bloods
• FBC - WBC
• raised ESR, raised CRP
• Blood cultures

Imaging
1st line • XR - May be helpful in dx of chronic osteomyelitis
o Thickening of the cortical bone + periosteum
o Elevation of the periosteum (Periosteum loosely attached to cancellous bone - two layers can separate - abscess can form between them)
o Loss of the normal architecture of the bone (especially trabecular architecture)
o Osteopenia
o Evidence of bone destruction

2nd line (under ix to consider) • Bone scan/MRI
o Imaging modality of choice for ix of acute osteomyelitis (most sensitive)
o Confirm the presence of osteomyelitis
- Bone deformity
- New bone formation from the cortex outwards
- Gas in soft tissues
- Reduced opacity
o Identify an abscess

• US
o Useful in acute osteomyelitis
o Look for signs of associated septic arthritis + infection
o May show collections, subperiosteal abscesses, adjacent joint infusions
o Helpful in guiding aspiration or biopsy for microbiological dx

• CT scan
o Useful for visualising extent of bone destruction

• Bone biopsy
o Culture + identify pathogen responsible
o Confirm dx

• PET scan
o Increased uptake of radioactive injectate in infected sites
o To differentiate between active infection and structural derangement of the bone

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11
Q

Idiopathic inflamatory myopathy

A

• Raised CK

• EMG
o Dead muscle cells –> abnormal electrical signal conduction + evidence of muscle membrane irritability
o Short duration, low amplitude, polyphasic units with early recruitment on voluntary activity

• Muscle biopsy to confirm dx
o Polymyositis - CD8+ T lymphocyte infiltrate the endomysium, muscle necrosis, atrophy
o Dermatomyositis - CD4+ T lymphocytes infiltrate the perimysium, perifascicular atrophy
o Inclusion body myositis  β-amyloid plaques collect within muscle fibres (can be revealed by Congo red staining)

•	Increase in muscle enzymes
CK
LDH 
aldolase
	Less specific than CK for monitoring activity
	Present in muscle + liver
 AST, ALT 
	Less specific for muscle injury than CK
myoglobin

• +ve ANA (in dermatomyositis + polymyositis)

• Myositis specific autoantibodies
o Polymyositis (anti-cytoplasmic antibodies against translational components)
 Anti-Jo12
 Anti- SPR

o Dermatomyositis
 Anti-M2
 Anti-mas

•  ESR +  CRP

• Increase Soluble CD30
o Expressed mainly by activated CD+ T cells
o Increase in polymyositis + dermatomyositis

• FBC – ACD (microcytic)

• MRI
o Large areas of inflammation, oedema, fibrosis, calcification

• US
o Image suggestive of inflammatory processes

To diagnose - CK + EMG
To confirm dx - muscle biopsy

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12
Q

Diagnosis of idiopathic inflammatory myopathy

A

Diagnosis of polymyositis (first four criteria must be met) + dermatomyositis (3 out of the first four + the 5th criteria must be met)

  1. Bilateral proximal myopathy – involving both thighs or both upper arms
  2. Increased muscle enzymes
  3. Abnormal electrical signal conduction on electromyography
  4. Lymphocyte infiltration + abnormal muscle degeneration on biopsy
  5. Presence of skin rashes
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13
Q

Sarcoidosis ix

A

• CXR
o Bilateral hilar lymphadenopathy (+/- hilar infiltrates)
o Pulmonary infiltration/fibrosis

• Raised serum calcium, raised urine calcium
o Due to dysregulated production of calcitriol by activated macrophages + granulomas
• Raised serum ACE (from T-cells)
• Raised ESR

• Biopsy (flexible bronchoscopy with transbronchial lung biopsy)
o Essential for dx
o Non-caseating granulomas
o Langhans giant cell

• FBC
o Anaemia
o Leukopenia/leucocytosis/eosinophilia
o Secondary to BM involvement

• BAL
o Lymphocytosis
o CD4-to-CD8 ratio >3.5

• PFTs
o To monitor disease
o Persistent decline in FVC indicates disease progression
o Restrictive/obstructive/mixed pattern

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14
Q

SLE ix

A
  • FBC – normocytic normochromic anaemia, leukopenia, thrombocytopenia
  • ESR + CRP – elevated
  • ANA – most sensitive but NON-diagnostic as it’s very non-specific
  • Anti-ds-DNA antibody – highly specific for SLE, confirmatory of the dx, level reflects disease activity
  • Anti-cardiolipin ab
  • Anti-Smith antibody – highly specific for SLE, confirmatory of the dx, ab against small ribonucleoproteins
  • U+E - raised U + Cr if pt w SLE have renal manifestations
  • Urinalysis – to assess renal involvement (haematuria, casts, proteinuria)
  • (Biopsy of the kidney – diffuse thickening of the glomerular capillary walls with “wire loop” structures) –might be in an SBA
  • Skin biopsy – only done when dx is in doubt, immune deposits at the dermal-epidermal junction on immunofluorescence, non-specific inflammation
  • Low complement levels – Complement C3 + C4 levels are decreased

APLS –> complication of SLE (thromboembolism, miscarriage, thrombocytopenia)
• Antiphospholipid antibodies – anticardiolipin, anti-b2-glycoprotein I, lupus anticoagulant – checked in lupus patients as APLS can occur secondary to autoimmune diseases like SLE
• APTT – may be prolonged in patients with antiphospholipid antibodies

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15
Q

Positive ANA anti-histone antibodies with negative anti-dsDNA antibodies

A

drug-induced lupus erythematosus
o Develops as a reaction to certain medication metabolised by N-acetylation in the liver
o Does ont affect the oral mucosa, CNS or kidneys
o SHIPP – sulphonamide, hydralazine, isoniazid, procainamide, phenytoin

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16
Q

Systemic sclerosis ix

A

• Antinuclear antibodies specific to scleroderma
o Limited cutaneous scleroderma
 Anti-centromere antibodies

o Diffuse cutaneous scleroderma
 Anti-topoisomerase I (Anti-scl 70)
 Anti-RNA polymerase III

• PFTs
o Look for restrictive lung disease + pulmonary HTN
o Restrictive lung disease - FEV1:FVC >70% (decrease in FVC)

• ECG
o RVH (large R wave in V1, smaller R wave in V5/V6)
o RAD
o Arrhythmias

• Echo
o Pulmonary HTN
o Increase in R ventricular systolic pressure = pulmonary artery systolic pressure

•	CXR
o	Bi-basilar interstitial infiltrates (interstitial lung disease)
o	R ventricular enlargement
o	Prominent central pulmonary artery
o	Peripheral hypervascularity

• R heart catheterisation
o To confirm dx of pulmonary artery HTN + evaluate the severity

• Other tests to look for organ involvement
o OGD – unexplained microcytic anaemia, new onset dysphagia, evaluate for strictures, Barret’s oesophagus, oesophageal adenocarcinoma
o Barium swallow – dysmotility (diminished oesophageal peristalsis + gastroparesis), reflux, strictures
o FBC – iron deficiency anaemia due to GIB, malabsorption
o U+Es – scleroderma renal crisis is characterised by the onset of acute renal failure (raised U + Cr), abrupt onset of HTN, MAHA
o ESR – usually normal, occasionally elevated
o CRP – occasionally elevated, particularly in severe disease
o Urine microscopy – normal but mild proteinuria with few cells or casts occurs with scleroderma renal crisis
o Serum muscle enzymes – elevated in scleroderma myopathy without weakness (if elevated also check TFTs to evaluate for an underlying myopathy from hypothyroidism)

17
Q

GCA ix

A

• Rised ESR (>50mm/h) + CRP [check before steroids]

• FBC
o Normochromic normocytic anaemia
o Normal WBC count or mild leukocytosis
o Raised plt

• LFTs
o AST, ALT, ALP often mildly elevated

•	Temporal artery biopsy  
o	Granulomatous inflammation
o	Multinucleated giant cells
o	Inflammatory infiltrate
o	not 100% sensitive (skip lesions)

• Temporal artery colour duplex US
o Used if biopsy is not readily available
o Wall thickening (halo sign), stenosis, occlusion

• Aortic arch angiography
o Ix to be considered
o May show stenosis of the subclavian, axillary, proximal brachial arteries

18
Q

Diagnosis of polymyalgia rheumatica

A

Core inclusion criteria for a dx of PMR include
• >50 y/o + duration of symptoms >2 weeks
• Bilateral shoulder +/- pelvic girdle aching
• Morning stiffness of >45 mins in duration
• Raised ESR/CRP

19
Q

Polyarteritis nodosa ix

A

• Absence of ANCA + absence of involvement of small vessels

• Conventional digital subtraction angiography
o Rosary sign – “buzzword”! (small aneurysms strung like the beads of a rosary)
o Microaneurysms + vessel ectasia + focal narrowing in medium-sized blood vessels

• Biopsy
o Focal + segmental transmural necrotising inflammation with fibrinoid necrosis in medium-sized vessels

  • Raised ESR, CRP
  • Raised fibrinogen as a marker of acute inflammation
  • Raised platelet count
  • Neutrophilia/oesinophilia
  • Normocytic normochromic anaemia
  • Decreased complement levels
  • HBV, HCV serology
  • Mild elevation of LFTs is common

Plt count is decreased in SLE+antiphospholipid syndrome

20
Q

Granulomatosis with polyangiitis/ Wegener’s granulomatosis ix

A
  • cANCA in the setting of the classic triad (otorhinolaryngeal, lung, renal involvement)
  • Histology - non caseating granulomas
  • CXR – cavitating lung nodules
  • Urinalysis – haematuria, proteinuria, dysmorphic RBC, RBC casts
  • Raised ESR, CRP
  • Raised Cr

• Renal biopsy - glomerular crescents

21
Q

Eosiophilic granulomatosis with polynagiitis (Chug Strauss syndrome ix)

A
  • pANCA against MPO (myeloperoxidase)
  • FBC, BAL – Increased eosinophils
  • Raised ESR, CRP
  • Raised IgG levels

• To assess for glomerulonephritis – raised U + Cr, urinalysis (haematuria, proteinuria, RBC casts)

• PFTs – reversible airway obstruction (asthma)
• CXR
Pulmonary opacities
Transient migratory pulmonary infiltrates
Pleural effusions

22
Q

Bechet’s disease ix

A

• Pathergy testing
Formation of pustule/ulcer within 24h-48h
Pathergy = exaggerated skin injury occurring after minor trauma

  • Raised CRP, ESR
  • HLA-B51
  • Angiography – to identify + assess aneurysms
  • Chest CT/ CTA – indicated when haemoptysis occurs to evaluate for pulmonary aneurysm
23
Q

Microscopic polyangiitis ix

A
  • pANCA against MPO
  • Raised ESR, CRP
  • Raised Cr
  • Urinalysis – proteinuria, haematuria

• Histology  no granulomas

24
Q

Takayasu aretritis ix

A

• Raised ESR/CRP

•	CTA (CT angiography + contrast) 
   Segmental narrowing
   Occlusion
   Dilation
   Aortic aneurysms
   Thickenning of vessel walls

• MRA (MR angiography + gadolinium contrast)
All of the features of CTA
Vessel wall inflammation + thickening
Oedema

  • Hypoalbuminemia
  • Incresased levels of fibrinogen, alpha-2-globulin + gamma globulin
25
Q

Polymyalgia rheumatica ix

A

• Raised ESR + CRP

• US
o Bursitis
o Joint effusions

• FBC
o To exclude myeloproliferative diseases that may present similarly to PMR

• Normal CK
o No damage to the muscles
o This distinguishes it from other inflammatory muscle disorders e.g. polymyositis

26
Q

How to differentiate between GPA + goodpasture’s syndrome?

A

Goodpasture’s syndrome also presents with LRT symptoms + glomerulonephritis
but there are no URT symptoms in goodpasture’s syndrome

27
Q

How to differentiate between GPA + goodpasture’s syndrome?

A

Goodpasture’s syndrome also presents with LRT symptoms + glomerulonephritis
but there are no URT symptoms in goodpasture’s syndrome

28
Q

How to differentiate between Takayasu arteritis + GCA?

A

Both are large vessel vasculitides

Look at the person’s age
Takayasu - <40, F>M, Asian, affects branches of the aorta

GCA - >50, F>M, affects carotid artery + branches

29
Q

OA VS RA radiography

A
OA - LOSS
Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts
RA
Loss of joint space
Soft tissue swelling
Juxta-articular erosions
Joint subluxation
30
Q

How to differentiate Granulomatosis with polyangiitis/ Wegener’s granulomatosis with microscopic polyangiitis

A

Granulomatosis with polyangiitis/ Wegener’s granulomatosis - non caseating granulomas

Microscopic polynagiitis - no granulomas

31
Q

American Rheumatism Association criteria

A
Dx of RA requires 4/7 
1 Morning stiffness >1h for >6w
2 Arthritis of hand joints (PIP, MCP, wrist) for >6w
3 Arthritis of >3 joint areas for >6w
4 Symmetric arthritis for >6w
5 Rheumatoid nodules
6 Characteristic XR findings*
7 Positive rheumatoid factor 

*joint space narrowing, soft tissue swelling, juxta-articular erosions, joint subluxation

32
Q

Rheumatoid arthritis bloods RA

A

Anti cyclic citrulinated antibodies - most specific

Rheumatoid factor - most sensitive

33
Q

Most specific antibody for SLE

Most sensitive antibody for SLE (but non-diagnostic)

A

Most specific antibody for SLE - anti-dsDNA

Most sensitive antibody for SLE (but non-diagnostic) - ANA