About the Test
Purpose of the test
The purpose of a cyclic citrullinated peptide antibody test is to detect CCP antibodies in the blood. CCP antibody testing is important for diagnosing rheumatoid arthritis and assessing its severity:
- Diagnosing rheumatoid arthritis: In people with symptoms, CCP antibody testing is used to help diagnose or rule out rheumatoid arthritis. As there is no single test that can diagnose rheumatoid arthritis, CCP antibody testing is considered in conjunction with other factors, including a patient’s symptoms and the results of other tests.
- Estimating disease severity: CCP testing can help doctors predict the progression of a patient’s rheumatoid arthritis. Patients with early rheumatoid arthritis who test positive for CCP antibodies are at an increased risk of worsening joint damage.
What does the test measure?
The cyclic citrullinated peptide antibody test identifies CCP antibodies in the blood. CCP antibodies are a specific type of antibody produced by the immune system called an autoantibody.
While most antibodies help the body fight disease by recognizing and neutralizing foreign substances like bacteria and viruses, autoantibodies don’t fulfill this important immune function. Instead, autoantibodies can act abnormally by targeting and attacking the body’s healthy cells and tissues.
CCP antibodies are detected in most patients with rheumatoid arthritis. Although less common, CCP antibodies may be detected in other autoimmune disorders, including Sjögren’s syndrome and lupus. Positive results for CCP antibodies can also occur in patients with active tuberculosis (TB) and in some patients with chronic lung disease.
When should I get a cyclic citrullinated peptide antibody test?
Patients should get a cyclic citrullinated peptide antibody test if this test is recommended by their doctor. Doctors may recommend CCP antibody testing if patients experience signs or symptoms of rheumatoid arthritis.
Symptoms of rheumatoid arthritis include joint pain when resting and moving. Joints may feel warm, tender, or swollen. Morning stiffness and stiffness after resting, usually lasting over 30 minutes, are also common symptoms. Additional symptoms of rheumatoid arthritis include fatigue, intermittent low-grade fevers, and a loss of appetite.
Because CCP antibodies are rarely found in patients without rheumatoid arthritis, CCP antibody testing may be performed to rule out a diagnosis of rheumatoid arthritis in patients suspected of having other types of autoimmune disorders such as psoriatic arthritis and juvenile idiopathic arthritis.
Finding a Cyclic Citrullinated Peptide Antibody Test
How to get tested
A cyclic citrullinated peptide antibody test takes place in a doctor’s office or other medical setting as a patient’s medical provider collects a sample of blood. Blood samples are then sent to a laboratory for a specific laboratory test that detects and measures CCP antibodies.
Can I take the test at home?
At-home test kits are available to collect blood samples that can then be mailed to a laboratory for analysis. Self-test kits may combine CCP antibody testing with testing for rheumatoid factor (RF), another lab test used to help diagnose rheumatoid arthritis.
Although at-home CCP antibody tests may be marketed as a form of screening for rheumatoid arthritis, it is important to know that screening for rheumatoid arthritis has not been proven to be beneficial in people without symptoms.
At-home testing is not a replacement for testing performed in a medical setting. Be sure to discuss testing for CCP antibodies with your doctor before taking an at-home CCP antibody test.
How much does the test cost?
The cost of a cyclic citrullinated peptide antibody test depends on where the CCP antibody test is performed and a patient’s health insurance coverage.
This test is usually covered by insurance. Patients may benefit from talking to their insurance provider for detailed information about out-of-pocket costs, such as copays and deductibles.
An at-home CCP antibody test costs around $100. The cost of an at-home test kit often includes the additional cost of mailing the blood sample to a laboratory.
Taking a Cyclic Citrullinated Peptide Antibody Test
Cyclic citrullinated peptide antibody testing requires a blood sample. Blood samples are often drawn from a vein on a patient’s arm. This procedure may take place in a doctor’s office, hospital, or other medical setting.
At-home CCP testing involves collecting a blood sample from a fingertip. The sample is produced by pricking a finger with a needle or lancet, then collecting a few drops of blood to be sent to a lab.
Before the test
Before being tested for cyclic citrullinated peptide antibodies, patients should tell their doctor about any medicines they are taking, including prescription medication, vitamins, and dietary supplements. Patients may need to stop taking certain substances eight hours before a CCP antibody test.
For patients taking an at-home CCP antibody test, it’s important to prepare by reading all instructions contained in the test kit. CCP testing kits walk patients through the pre-test preparation, which includes drinking sufficient water before taking the test, getting testing supplies ready, and cleaning the site where the blood sample will be collected.
During the test
In order to collect a blood sample for cyclic citrullinated peptide antibody testing in a medical setting, a doctor, nurse, or other health professional will use a small needle to draw blood from a patient’s vein. Most often, blood is drawn from a vein on the inside of the elbow or on the back of the hand. The process for drawing blood, also called venipuncture, includes:
- Cleaning the site to kill germs that may be on the skin
- Tying an elastic band above the elbow
- Inserting a needle into the selected vein
- Allowing blood to collect in a vial or other container attached to the needle
- Removing the elastic band from the upper arm
- Removing the needle
Patients may feel a small amount of pain or stinging when the needle is inserted into the vein and removed. Venipuncture usually takes less than five minutes.
For at-home CCP antibody testing, patients begin by preparing the lancet or needle, placing their hand on a firm surface, and pressing the lancet or needle into the skin. Patients then allow several drops of blood to fall into a prepared collection device. If it’s difficult to produce enough blood for the sample, test kit instructions may instruct patients to massage a portion of the finger to encourage bleeding.
After the test
After the needle is withdrawn from a patient’s vein, the site is covered with a bandage to reduce bleeding. Although there is very little risk to having blood drawn, patients may have slight pain or bruising at the site where the needle was inserted. Most symptoms go away quickly.
An at-home testing kit may provide a small bandage to cover the tip of the finger and stop any bleeding. Patients then prepare the blood collection device for shipment. It’s important to send the sample via delivery carrier within 24 hours of collection.
There are no restrictions on activities, including driving, sports, or work after taking a cyclic citrullinated peptide antibody test.
Cyclic Citrullinated Peptide Antibody Test Results
Receiving test results
After being tested for cyclic citrullinated peptide antibodies, results may be available within a few business days. Results may be communicated to a patient over the phone, by mail, or electronically. Because CCP antibody testing is often used in combination with other tests, doctors may wait to share results until additional testing is completed.
At-home CCP antibody testing may require additional time before results are available to a patient. Once the test sample is mailed to the appropriate laboratory and the analysis is completed, results may be available through the company’s website or a smartphone app. At-home testing companies may connect patients to a health professional for additional support in understanding their test results.
Interpreting test results
On a test report for cyclic citrullinated peptide antibodies, a patient will see whether or not CCP antibodies were found in the blood. A negative result on a CCP antibody test indicates that no CCP antibodies were detected in the blood. A positive result indicates that CCP antibodies were detected in the blood sample.
The results of CCP antibody testing are used in combination with the results of a physical exam, a rheumatoid factor (RF) test, and other test results to determine whether a patient has rheumatoid arthritis. CCP antibodies are detected in over 75% of patients with rheumatoid arthritis and almost never detected in patients without this disease.
In patients with symptoms of rheumatoid arthritis, testing positive for both CCP antibodies and RF suggest that a patient is likely to have rheumatoid arthritis. Testing positive for CCP antibodies and negative for RF may indicate that a patient is likely to develop rheumatoid arthritis in the future or is already in the early stages.
Testing negative for both CCP antibodies and RF indicates that a patient is less likely to have rheumatoid arthritis. In this case, a patient’s doctor may order additional tests to determine the cause of their symptoms.
Patients may find it helpful to talk to a rheumatologist when interpreting CCP antibody test results. Diagnosing rheumatoid arthritis and other autoimmune disorders can be a complex process. Rheumatologists specialize in diagnosing and treating autoimmune disorders and other conditions of the joints, muscles, and bones. Rheumatologists can answer questions about rheumatoid arthritis and help patients understand the implications of test results.
Are test results accurate?
Cyclic citrullinated peptide antibody testing is a standard aspect of diagnosing rheumatoid arthritis and is generally considered to be accurate. No medical test is perfect though, and issues in the processing of samples or during laboratory testing may produce errors or inconclusive results. Medical laboratories take special precautions to reduce the incidence of errors.
When reviewing test results, patients can discuss the reliability of CCP antibody testing with their doctor.
Do I need follow-up tests?
Patients may need follow-up testing after a cyclic citrullinated peptide antibody test. Follow-up testing will depend on the purpose of the CCP antibody test, the test results, and other factors individual to each patient.
Diagnosing rheumatoid arthritis requires that doctors evaluate several factors, including a patient’s symptoms, the results of a physical exam, and both laboratory and imaging tests. Patients being tested for rheumatoid arthritis typically require additional tests either at the same time or following a test for cyclic citrullinated peptide antibodies.
Rheumatoid arthritis testing involves testing a patient for CCP antibodies and rheumatoid factor (RF), as well as testing for evidence of inflammation in the blood. Tests that detect inflammation characteristic of rheumatoid arthritis include erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP).
If a patient is experiencing symptoms of rheumatoid arthritis and both RF testing and CCP antibody testing are negative, doctors may recommend antinuclear antibody (ANA) testing, testing for hepatitis B and hepatitis C, a synovial fluid analysis, as well as additional imaging tests.
Questions for your doctor about test results
As patients review test results with a doctor, the following questions may be helpful to better understand the significance of test results:
- Were CCP antibodies detected in my blood?
- What can this test result tell me about the cause of my symptoms?
- What follow-up tests are recommended?
How is a cyclic citrullinated peptide antibody test different from a rheumatoid factor test?
Both CCP antibody testing and rheumatoid factor testing detect types of autoantibodies produced by the immune system that attack healthy cells and tissue. Both tests are standard diagnostic tests that help diagnose rheumatoid arthritis and other health conditions.
Testing for CCP antibodies offers more definitive evidence of rheumatoid arthritis compared to testing for rheumatoid factor. Unlike CCP antibodies, which are rarely detected in patients without rheumatoid arthritis, RF factors may be detected in some healthy people and in patients with other autoimmune disorders.