1. MSK Rheum 2 Flashcards
What conditions is anti-RNP antibody associated with?
SLE and MCTD
MCTD has higher titres than SLE
Which condition is anti-Smith antibody associated with, and state spec and sens:
Anti-Smith = SLE
30% sensitivity, but 99% spec
Anticardiolipin is associated with antiphospholipid syndrome. Which other antibodies / blood tests are associated?
APS
Anti-beta2glycoprotein and lupus anticoagulant.
Thrombocytopenia
Increased APTT
Risk of fetal loss is much higher in those with autoimmune connective tissue disorders, especially in SLE. The mnemonic PATH represents serious factors for adverse pregnancy outcomes:
Proteinuria
APS
Thrombocytopenia
Hypertension in early pregnancy
Treatment of PMR:
Polmyalgia Rheumatica
Steroids.
They usually respond dramatically to steroids, so if they don’t then consider another diagnosis.
Reassess 1 week after starting steroids.
Should also start bisphosponates / PPI
Typical patient / features of PMR:
> 60, white woman.
Stiffness in proximal limbs / shoulder and pelvic girdles.
Rapid onset of <1 month
Polyarthralgia
Lethargy, depression, low grade fever , anorexia and night sweats can also be present.
Investigations of PMR:
ESR (>40)
CRP elevated or normal
Bloods for differentials include myeloma, thyroid, CK for myositis etc.
50% of patients with GCA will also have features of PMR. Has similar presentation in terms of presentation over <1 month. Give some features, excluding ocular:
Headache
Fatigue
Jaw claudication
Tender palpable temporal artery
+ lethargy, fever, night sweats, anorexia
Visual involvement in GCA:
Anterior Ischaemic Optic Neuropathy; occlusion of posterior ciliary artery. Fundoscopy shows swollen pale disc with blurred margins.
Amaurosis fugax
Sudden temporary loss of vision
Can be permanent, must be treated asap with IV methylpred
Which vasculitis is referred to as ‘pulseless disease’, give some symptoms and how is it diagnosed?
Takayasu’s arteritis
Large vessels, affecting the aortic arch and pulmonary artery, causing occlusion / stenosis.
Claudication particularly in arm.
CT/MRA
Which infection is polyarteritis nodosa particularly associated with?
Hepatitis B
Cardinal features for all vasculitides:
Small:
Microscopic - GN causing renal failure + diffuse alveolar haemorrhage
GPA - saddle nose, resp and renal
EGPA - late onset asthma
Medium:
PAN - hep B, renal
Kawasaki - kids, high fever >5days
Large:
Takayasu - pulseless disease, aorta + pulm artery
ANCA are associated with small vessel vasculitides; broadly speaking which is associated with which?
cANCA = GPA
pANCA = EGPA + MPA
pANCA also associated with UC (70%), PSC, Anti-GBM disease and Crohn’s (20%)
Investigation into ANCA vasculitis:
Urinalysis inc haematuria and proteinuria
Urea and creatinine
FBC ?anaemia
CRP ?raised
ANCA
CXR
Monitoring tools in:
RA
Ankylosing Spondylitis
PsA
RA = das28 + CRP
Ankylosing spondylitis = CRP and ESR
PsA - screening is done with PEST for people with psoriasis
Crystals seen in gout vs pseudogout:
Gout = negatively birefringent needles
Pseudogout = weakly positive birefringent rhomboids
Pseudogout is strongly associated with increasing age, and if there is a diagnosis <60 years there is usually one of the following underlying risk factors:
Haemochromatosis
Hyperparathyroidism
Low magnesium or phosphate
Acromegaly
Wilson’s disease
What is deposited in the synovium in pseudogout?
Calcium pyrophosphate dihydrate crystals
Most commonly affected area in a first presentation of gout:
1st MTP
First line investigation in acute gout presentation:
Serum urate / uric acid levels
> 360 supports diagnosis
<360 = repeat 2 weeks post flare
+ synovial fluid analysis
XR features of gout:
Early sign = joint effusion
Well defined punched out erosions with sclerotic margins
Overhanging edges sometimes
Preservation of joint space until late stage
NO periarticular osteopenia
Tophi present (within soft tissue)
Gout is due to chronic hyperuricaemia >0.45mmol/L levels. Give some causes of decreased excretion and increased production respectively:
Decreased excretion of uric acid:
Drugs e.g. thiazide diuretics
CKD
Lead toxicity
Increased production of uric acid:
Myeloproliferative / lymphoproliferative disorders
Cytotoxic drugs
Severe psoriasis
NSAIDs and colchicine are first line management in acute attacks of gout. What is offered long term after a first attack?
Allopurinol (needs colchicine cover initially to prevent flare).
Dose should be titrated to aim for serum uric acid <360.
Started after flare, as should be decided when patient is not in pain.
Lifestyle modifications in gout:
Reduce alcohol, and don’t take any whilst flare
Stop smoking
Low weight
Avoid high purine diet
Stop precipitating drugs
Patients with hypertension, consider losartan
Increase vitamin C
2nd line urate lowering therapy:
Febuxostate is another xanthine oxidase inhibitor.
Uricase is third line.
