Patient presenting with cutaneous vasculitis, glomerulonephritis, peripheral neuropathy, which of the following will help in diagnosis?
Ref. API Textbook of Medicine. Pg. 1313
 
Cutaneous vasculitis features – Diagnosis
Anti-neutrophil cytoplasmic antibodies (ANCAs):

Group of autoantibodies
IgG type mainly,
Produced against antigens in cytoplasm of neutrophil granulocytes & monocytes.
Particularly associated with systemic vasculitis, so called “ANCA-associated vasculitis”.
c-ANCA – Abs against MPO, p-ANCA -  Abs Against PR3
ANCA
RA factor
Hbsag
MIF