Testing for ANCA autoantibodies in the blood helps in diagnosing 3 types of AAV – GPA, MPA and EGPA. About 8 in 10 people with GPA and MPA, and around 4 in 10 people with EGPA have detectable levels of ANCA.¹ To look for ANCA in your blood, your doctors will first do a blood test, which will then be examined in a laboratory

While these tests are very useful, it is important to be aware that ANCA can also be found in people with other diseases such as chronic infections. In addition, some people with GPA or MPA do not have detectable levels of ANCA and their doctor will make a diagnosis based on the clinical picture (an assessment of all test results and symptom information).

Signs of inflammation (known as inflammatory markers) can usually be detected in the blood. Your doctors will usually look for these by measuring your blood cell lowering rate (which shows how fast the solid parts of your blood move in a test tube) and your level of C-Reactive protein (or CRP – a type of protein that the liver produces in higher quantities when inflammation occurs).

Although the results of these tests can indicate your body is inflamed, they do not show which type of inflammation you have, so on their own, they are not sufficient for your doctors to diagnose AAV.

If your doctors suspect you may have kidney disease, they will investigate how well your kidneys are working by doing a blood test. This will typically look at your levels of creatinine (which supplies muscles with energy) and urea (the main breakdown product of proteins). Higher than usual levels of either can indicate that your kidneys are not eliminating them correctly after use, and that your kidney function may be impaired.

It is important for urine to be examined regularly so that small changes in urea and creatinine can be detected as soon as possible and any kidney damage can be minimised.

• When you arrive at the hospital you may need to have a blood test

• You might feel a small pushing sensation as the biopsy is taken

• After the biopsy you may need to go for a scan

• You may experience bruising and a dull ache in the general area of the biopsy

• Most patients go home on the same day – however, depending on where your biopsy is taken from you may need some bed rest and your doctor will advise you on this

• Make sure to let your doctor know of any medications that you are taking

• Regularly check your biopsy site and contact your doctor immediately if you notice any visible symptoms or changes in how you feel