The term vasculitis refers to inflammation of blood vessels and
represents a heterogeneous group of clinical disorders.
Each form of vasculitis can produce a distinct clinical picture,
but in many cases immunology testing can differentiate, confirm and
monitor the presence of vasculitis. Other forms of vasculitis, for
example, Behçet's disease and primary cerebral vasculitis are not
associated with any specific blood tests.
The main immunological tests are antinuclear
antibody (ANA - for SLE a connective tissue diseases) and anti-neutrophil
cytoplasmic antibody (ANCA - Wegener's granulomatosis and other
It is important to understand that neither of these tests is
specific; they can both be positive in infection and in liver
disease. This makes these tests very unsuitable as 'screens' in
patients with vague symptoms such as malaise, weight loss or
Other tests include complement C3 and C4, which are
altered in immune complex disease and cryoglobulin.
(Last updated October 9th 2014)