Tests
Antineutrophil Cytoplasmic Antibodies (ANCA) Test
An ANCA test looks for antineutrophil cytoplasmic antibodies (ANCA) in a sample of your blood. Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria. ANCAs, however, are autoantibodies, which are antibodies that attack your own healthy tissues and organs by mistake. This can lead to the development of an autoimmune disease .