Systemic Sclerosis and Inflammatory Myopathies Flashcards
What are the two main subsets of scleroderma?
limited cutaneous and diffuse cutaneous
What genes are involved in scleroderma?
HLA-DRB1, STAT4, interferon
What environmental factors are associated with scleroderma?
silica, organic solvents, vinyl chloride
What are the three pathologic pillars of systemic sclerosis?
inflammation (synovitis, myositis), vasculopathy (raynaud’s, abnormal capillaries, ischaemic changes) and interstitial fibrosis (in skin = scleroderma, but also happens in other organs e.g. lung, gut, renal)
What is the difference between diffuse cutaneous and limited cutaenous?
diffuse has a more rapid onset, has earlier internal organ involvement, more constitutional symptoms
in limited cutaneous skin changes are limited to arms and face
Which antibodies are associated with diffuse cutaneous scleroderma?
Scl-70 antibodies, anti-RNA polymerase I, III, ANA with nucleolar pattern
What is CREST syndrome?
limited cutaneous scleroderma: Calcinosis, Raynaud’s, oEsophageal dysmotility, Skin changes, Telangiectasia
What antibodies are associated with limited cutaneous scleroderma?
anti-centromere antibodies
Is pulmonary arterial hypertension more common in diffuse or limited?
equal 10% in both
Is ILD more common in diffuse or limited?
diffuse
Is scleroderma renal crisis more common in diffuse or limited?
diffuse
What organ involvement is associated with anti Scl-70 antibody?
intestitial lung disease
What organ involvement is associated with centromere antibodies?
protection from ILD and renal disease
What organ involvement is associated with anti RNA polymerase III antibodies?
renal, skin, malignancy
What is the leading cause of death in scleroderma?
cardiopulmonary manifestations - pulmonary fibrosis, pulmonary hypertension
What is the treatment for scleroderma?
no overall disease modifying therapy - organ specific treatment
How do you diagnose interstitial lung disease?
high resolution CT shows non specific interstitial pneumonitis
Which patients with ILD should be treated?
patients with early diffuse scleroderma with positive anti-Scl70 or elevated CRP, or based on the grade of disease on HRCT, FVC% or DLCO % less than lower limit of normal or clinically meaningful decline, desaturating on 6MWT, symptoms from ILD
How often should patients get spirometry?
for every 3-4 months for the first 5 years and then yearly
What conservative measures can be used to treat ILD?
treat GORD, quit smoking, vaccinations, supplemental O2
What is first line therapy for ILD?
mycophenolate 3g/day
What are other reasons patients with scleroderma may have declining DLCO other than ILD?
neuromusclar dysfunction (myositis), thoracic restriction (scleroderma), aspiriation (GORD), deconditioning, pulmonary hypertension
How do you diagnose pulmonary hypertension?
with right heart catheter
What screening should be done for scleroderma patients for PAH?
TTE and RFTs OR pro-BNP and RFTs
What is the therapy for scleroderma associated PAH?
endothelial receptor antagonist or PDE-5 inhibitor or riociguat
What are the features of scleroderma renal crisis?
abrupt onset of moderate to severe hypertension, normal urine sediment, progressive renal failure
How common is scleroderma renal crisis in diffuse scleroderma?
10-20%
What is a trigger for scleroderma renal crisis?
corticosteroids
What is the treatment for scleroderma renal crisis?
effective and prompt blood pressure control with an ACE inhibitor
What is the treatment for raynaud’s phenomenon?
dihydropyridine calcium channel blockers, PDE5 inhibitors, topical nitrates
What are the different types of gut involvement in scleroderma?
rigidity of facial muscles/tongue, reduced saliva production, incoordination of swallowing, GORD, bloating, distension, bacterial overgorwth, intussucception, pneumatosis intestinalis, faecal incontinence
What are the 4 classes of idiopathic inflammatory myopathies?
polymyositis
dermatomyositis
inclusion body myositis
immune mediated necrotising myopathy
What are the clinical features of dermatomyositis and polymyositis?
symmetrical proximal muscle weakness
What are the features of a dermatomyositis rash?
gottron’s papules (on extensor surface MCP and PIP joints), shawl sign, heliotrope rash (around eyes), periungal erythema
What are the laboratory findings for DM and PM?
elevated muscle enzymes (CK, transaminases, LDH, aldolase), antinuclear antibodies
What non laboratory investigations are useful in DM and PM?
EMG and MRI
What screening should be done for malignancy in patients with inflammatory myopathies?
medical history, physical examination of breast, rectal and pelvic examination, age appropriate screening (mammography, colonoscopy)
Which malignancies are most commonly associated with dermatomyositis?
cervix, lung, ovaries, pancreas, bladder, stomach
What investigations should be done for non malignant complications of inflammatory polymyopathies?
cardiac (TTE and ECG)
pulmonary (HRCT, RFTs)
oesophageal (oesophageal motility studies)
What is the treatment for inflammatory polymyopathies?
high dose glucocorticoids (taper over a year), steroid sparing agents (azathioprine, methotrexate, IVIG, rituximab, plasma exchange)
What are the clinical features of inclusion body myositis?
insidious onset of assymetric, proximal leg weakness for up to 5 years
weakness of distal finger flexor muscles
muscle atrophy
dysphagia
