Cytoplasmic Antineutrophil Cytoplasmic Antibody (C-ANCA) Test

Antineutrophil cytoplasmic antibodies (ANCA) affect the type of human white blood cells like neutrophils. Neutrophils are important white blood cells that help fight infections caused by bacteria. ANCA combines with two proteins usually found in the fluid present in the white blood cells. These two proteins are Proteinase 3 (PR3) and Myeloperoxidase (MPO).

c-ANCA, PR3-ANCA or antineutrophil cytoplasmic antibodies generally produced by the body act against one of its proteins. These antibodies result from the binding of ANCA to antigen targets throughout the neutrophil cytoplasm. A typical protein target of c-ANCA is proteinase 3 (PR3).

A proteinase 3 (PR3) or c-ANCA test usually detects, diagnoses, and monitors certain forms of autoimmune ANCA swelling in blood vessels that cause severe health-related problems. The test helps your doctor to diagnose and treat the disorders.

Loss of hearing, redness in the eyes, difficulties in vision, skin rashes, difficulty in breathing, respiratory problems, protein in the urine, abdominal pain, and fever are some signs and symptoms of c-antineutrophil cytoplasmic antibodies.

Majorly, the presence of c-ANCA affects blood vessels in the different parts of the body. It can cause autoimmune dysfunction like inflammation in blood vessels (vasculitis) like arteries, veins, and capillaries, leading to further serious health problems.

Almost 85% of affected patients indicate acute cytoplasmic antineutrophil cytoplasmic antibodies with a higher frequency noted in patients with Granulomatosis with polyangiitis disease.

Other names of the c-ANCA Test

• c-ANCA (Anti-Neutrophil Cytoplasmic Antibodies) Test
• Cytoplasmic Antibody Test
• Cytoplasmic Neutrophil Antibodies Test
• Anti-Neutrophil Cytoplasmic Ab Test
• Autoantibodies to Proteinase 3 Test

What does the c-ANCA test measure, and who is this prescribed for?

The c-ANCA test measures the presence of proteinase 3 or c-antineutrophil cytoplasmic antibodies in the blood. Positive presence can be a sign of several health conditions related to the blood or organs of the body. A doctor may recommend a c-ANCA antibody test if you have symptoms that are as follows:

• Difficulties in hearing or permanent loss of hearing.
• Watery, or continuous passing of stool (diarrhoea).
• Mild to severe abdominal pain.
• Redness, itching, and stiffness in eyes.
• Difficulties in vision like blurred vision or permanent loss of vision.
• Skin rashes or sores.
• Running nose.
• Shortness or difficulties in breathing.
• Abdominal cramps.
• Fever.
• Fatigue.
• Bleeding in the rectum.
• Reduction in the development or growth of children.

The test also may be prescribed in case of:

• Major problems like pneumonia.
• Damage to the lungs.
• Mild to severe kidney problems like proteinuria (in the urine), can lead to kidney dysfunction.
• Damage or disease in several parts of the body like skin, joints, and bone.

The presence of proteinase 3 or c-antineutrophil cytoplasmic antibody in the blood cells for a c-ANCA test to determine the seriousness of the damage or disease of the body where these signs and symptoms occur.

The c-ANCA test results help in the prognosis or diagnosis of any autoimmune disease. In case of positive results, one needs further treatment and monitoring by a physician, rheumatologist, or immunologist. A doctor may recommend you repeat the test after every three months.

Cyclophosphamide and corticosteroids may be used in the treatment of positive c-ANCA vasculitis.

The positive presence of acute cytoplasmic antineutrophil cytoplasmic antibodies can affect the patient's health, while a negative presence means there is no risk to health.

The normal c-ANCA ranges for detecting proteinase 3 or c-antineutrophil cytoplasmic antibodies are:

• The presence is determined as negative when it has a range lower than or equal to 19 AU/mL.
• The presence is determined as equivocal (not determined) when it has a range of 20 - 25 AU/mL.
• The presence is determined as positive when it has a range greater than or equal to 26 AU/mL.

These expected ranges may vary with several laboratories because different laboratories have different methods of testing.

There are mild to severe health problems due to the high positive presence of acute cytoplasmic antineutrophil cytoplasmic antibodies in the blood, while the negative value does not affect health.

Positive c-ANCA indicates-

1. Granulomatosis with polyangiitis (GPA): A medical condition combined with a high positive presence of c-ANCA in the blood. A patient with GPA has inflammation in blood vessels, which majorly affects the ears, nose, throat, lungs, and kidneys. The symptoms can affect the vessels by narrowing, thickening or stretching them, which causes a reduction in blood supply to the tissues or organs of the body.

2. Chronic pneumonia: Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or purulent material, causing cough with phlegm or pus, fever, chills, and difficulty breathing. Organisms like bacteria, viruses, and fungi can cause pneumonia. Severe or chronic pneumonia becomes life-threatening and can affect your immune system.

3. Actinomycosis: An infection generally caused by the bacterium Actinomyces israelii due to the positive presence of proteinase 3 or c-ANCA in the blood. Actinomycosis most commonly affects the face and neck because of the bacteria's usual location in the nose and throat.

Negative c-ANCA indicates -

The negative presence of the proteinase 3 or c-ANCA test means you are not suffering from auto-immune vasculitis or other conditions related to c-ANCA.

A simple blood sample or serum is needed to undergo a c-antineutrophil cytoplasmic antibody test. This test does not require any specific preparations.

Test Preparation

An acute cytoplasmic antineutrophil cytoplasmic antibody test is a serum blood test that does not require any preparation. The blood sample is collected by drawing it from one of the forearm veins. The collected sample is sent to the laboratory for examination. This procedure is simple does not have any risk and usually takes 5 minutes.

What are the parameters included in the test?

The c-antineutrophil cytoplasmic antibody test measures the presence of acute cytoplasmic antineutrophil cytoplasmic antibodies in the blood. These are autoantibodies to the type of white blood cells called neutrophils. The high positive results of c-ANCA in the blood can cause severe health-related problems.

How frequently should you take this test?

With the positive results of proteinase three or c-antineutrophil cytoplasmic antibodies in the blood, your doctor may recommend you take the test every three months. It is done to monitor the treatment of several health conditions that may occur with c-ANCA in the blood.

You might repeat the test annually when the previous test results are average or c-ANCA is not present in the blood.

Granulomatosis with polyangiitis, Chronic pneumonia, Bowel disease