Rheumatology

Question 1

What tests will you send off to screen for a vasculitic cause?

Answer 1

FBE for white cells
Urea, Cr and egfr for renal function
ESR, CRP to assess chronicity of inflammation
LFT, Hepatitic serology (disease-associated vasculitis)
Serum cryoglobulins
Urinalysis with urinary sediment
Blood cultures to exclude infection

Question 2

What are some additional specific tests for vasculitis that you can send off?

Answer 2

ANA - SLE, Sjogren’s, Systemic sclerosis
Complement - LOW complement 4 levels are present in mixed cryoglobulinemia and SLE but not other forms of vasculitis
ANCA - looking for necrotising small-vessel vasculitis (AAV) - antibodies against MPO and Proteinase-3
HRCT - if chest symptoms
Electromyography - ?mononeuritis multiplex
Lumbar puncture - Primary angiitis of CNS (PACNS) has an aseptic meningitis pattern - elevated protein, lymphocytic pleocytosis, oligoclonal bands with increased IgG
Imaging - CT, MRI, conventional catheter-based angiography e.g., to look at renal/mesenteric arteries (microaneurysms and abrupt cut-offs)
Biopsy - e.g., temporal artery, renal, skin punch biopsy