Vasculitis

Testing

Initial testing will look at simple blood and urine tests

• Full Blood Count (FBC) – this test is used to look for complications of the disease and its treatment. It evaluates the patient’s red cells and haemoglobin such as anaemia, and checks the white blood cell count which can be increased in infection, and reduced with some treatments
• Erythrocyte sedimentation rate (ESR) – this test shows the presence of inflammation in the body and helps monitor the activity of the disease 
• C-reactive protein test (CRP) - this test also indicates inflammation and tests for the activity of the disease.
• Urea & electrolytes / creatinine – this test roughly assesses the kidney function
• Liver function tests (LFT)
• urine dipstick, microscopy – looks for presence of protein, red and white cells in the urine, which can indicate inflammation in the kidney
• ANCA – anti-neutrophil cytoplasmic antibody is an useful marker for primary systemic vasculitis conditions

More complicated tests may be required

• Tissue biopsy – the gold standard test for diagnosis of vasculitis is to take a biopsy of affected organ e.g. skin, kidney, nerve
• Radiological imaging can be helpful e.g. chest x-ray, CT scan chest, sinuses
• Nerve conduction studies or nerve biopsy may be useful if there are symptoms of numbness or tingling
• In some types of vasculitis, examination of the blood vessels by angiography can be useful such as angiography of the bowel in polyarteritis nodosa

The blood tests will enable the doctor to assess whether there is any inflammation in the blood which would suggest vasculitis, and importantly the urine test will help assess whether there is any suggestion of kidney abnormalities.

In the 1980’s, a new blood test was introduced which was associated with a number of vasculitic conditions, in particular the group of primary systemic vasculitis mentioned above. The ANCA antibodies are directed against a blood cell called the neutrophil and more particularly against the cytoplasm (the outer part) of the cell. While this is a helpful test, we now know that it is not diagnostic by itself. Tissue biopsy remains very important.