Autoimmune Disease Testing

Your immune system plays an important role in keeping you healthy by identifying foreign substances, such as viruses and bacteria, and fighting them off before they make you sick. However, the immune system can sometimes turn against your own body. Autoimmune disease happens when the immune system mistakes healthy tissue for something foreign and attacks it.

There are more than 24 million Americans living with autoimmune diseases, which affect twice as many women as men.1,2 AVISE® CTD uses patented biomarkers—which identify antibodies associated with specific diseases—to provide more in-depth diagnostic information for autoimmune disease than other lab tests, allowing your doctor to reach an accurate diagnosis quicker.

Image

How Providers Diagnose Autoimmune Disease

An autoimmune condition can cause various symptoms, depending on the type of condition you have, and some symptoms of one disease can be found in patients with a different disease. Common autoimmune disease symptoms include joint pain or swelling, muscle aches, skin changes or rashes, chronic fatigue, weakness, swollen glands, fevers and digestive issues.3 Common autoimmune diseases include:
  • Antiphospholipid syndrome
  • Autoimmune hepatitis
  • Autoimmune thyroid disease (Hashimoto’s or Grave’s disease)
  • Celiac disease
  • Inflammatory myopathies (polymyositis or dermatomyositis)
  • Inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
  • Systemic Lupus Erythematosus (SLE)
  • Multiple sclerosis
  • Rheumatoid arthritis
  • Scleroderma
  • Sjögren's syndrome
  • Type 1 diabetes
Diagnosing an autoimmune disease is notoriously difficult and complex. It often takes years of evaluating vague symptoms, many of which can exist in several autoimmune conditions. Your healthcare provider will consider your lifestyle habits, medication use, personal medical history and any history of autoimmune diseases in family members to reach a diagnosis. Autoimmune disease diagnosis also involves the interpretation of clinical symptoms as well as a series of autoimmune disease tests and sometimes can involve multiple doctors. This can be frustrating to both patients and their providers. AVISE testing aims to change that through advanced diagnostic testing. With a two-tiered approach that is more sensitive and specific than autoimmune testing of the past, your doctor can reach the appropriate diagnosis and begin an appropriate treatment faster.

Types of Autoimmune Disease Tests

Antinuclear antibody, or ANA, testing has been used as a blood test for autoimmune disease diagnosis for more than 50 years. The ANA test is still considered the gold standard for initial screening for SLE due to the test’s high sensitivity for identifying individuals who may have SLE. Negative ANA test results decrease the odds of an SLE diagnosis substantially. However, the ANA test is not very specific—it can be positive in the setting of various autoimmune diseases or even in those who do not have autoimmune disease. A positive ANA test result is not definitive and is often considered a first step toward diagnosing autoimmune disease. If your ANA test is positive, you will need additional testing for other specific autoimmune conditions and clinical evaluation of your symptoms by your medical provider before you can obtain a formal diagnosis.

If you have a positive ANA test and your symptoms suggest a specific autoimmune condition, your provider often will recommend a blood test to detect proteins called autoantibodies unique to that condition. Autoimmune diseases prompt the immune system to make antibodies that attack autoantibodies, and while an ANA test can identify the presence of autoantibodies generally, more sensitive tests can detect distinct autoantibodies that tell your provider which condition you may have.

Your provider may order any of the following blood tests:

  • C3 and C4 complement test is a blood test to measure levels of proteins that are nonspecific biomarkers for inflammation and can be elevated in autoimmune disease or in response to infection or other inflammatory conditions. Produced by the liver, C3 and C4 are sometimes used in screening but are not always reliable in definitively diagnosing autoimmune disease since these protein levels can vary from person to person and can fluctuate over time.
  • Extractable nuclear antigen (ENA) is a blood test often performed after positive ANA testing, and it looks for autoantibodies that can interact with the cell nucleus. Other common autoantibody tests—some of which may be included in an ENA panel—include the following:
  • Anti-double-stranded DNA (anti-dsDNA) antibody test is for lupus and can also be used to monitor lupus activity.
  • Anti-Smith (anti-Sm) antibody test is for lupus and can be used to rule in a lupus diagnosis.4
  • Anti-Sjögren Syndrome-A (anti-SSA/anti-Ro) antibody test is for Sjögren's syndrome. A positive SSA test result can also suggest lupus.
  • Anti- Sjögren Syndrome-B (anti-SSB/La) antibody test is a more specific test for Sjögren's syndrome compared to anti-SSB antibodies.
  • Anti-centromere protein antibody (Anti-CENP) test is for scleroderma.
  • Anti-topoisomerase I (Anti-Scl-70) antibody test is for scleroderma and other connective tissue diseases.
  • Anti-ribonucleoprotein (Anti-RNP) antibody test is for mixed connective tissue and other rheumatic diseases, but positive results can suggest lupus as well.
  • Anti-cyclic citrullinated peptide (Anti-CCP) antibody test is for rheumatoid arthritis.
  • Anti-histidyl transfer RNA synthetase (Anti-Jo-1) antibody test is for types of myositis, such as dermatomyositis and polymyositis, and inflammatory myopathies.

AVISE Detects Differently

We know how important it is to have a quality test so you can put a name to what is causing your symptoms, get an accurate diagnosis and start treatment to manage your symptoms. Not all tests are sensitive enough or effective at picking up abnormalities that are associated with autoimmune conditions.

AVISE testing uses advanced technologies and patented biomarkers to improve sensitivity of testing. AVISE offers several tests to identify autoimmune diseases, such as:

  • Antiphospholipid syndrome
  • Autoimmune thyroid disease
  • Dermatomyositis
  • Fibromyalgia
  • Lupus
  • Polymyositis
  • Rheumatoid arthritis
  • Scleroderma, also known as systemic sclerosis
  • Vasculitis

Healthcare providers who order AVISE receive results within five business days after the blood sample is taken.

ANA testing is performed by immunofluorescence assay, which uses a stain that glows to help lab technicians see abnormal patterns in the cells. Exagen, the maker of AVISE tests, was the first lab in the U.S. to utilize NOVA View®, which uses a high-resolution microscope to improve clarity and create digital photographs of antibodies that bind to your cells. Digital photographs allow for multiple views of the cells for a thorough assessment for autoantibodies.

The AVISE CTD lupus test can help diagnose lupus as well as connective tissue diseases, myopathies, rheumatoid arthritis, autoimmune thyroid disease, and antiphospholipid syndrome, which sometimes coexist with lupus. AVISE CTD can also help patients with fibromyalgia determine whether an autoimmune disease is present alongside their fibromyalgia. A type of ENA panel, the AVISE CTD tests for 23 biomarkers (specific autoantibodies) seen in certain autoimmune diseases. Most ENA panels only test for a handful.

AVISE CTD uses patented biomarkers called Cell-Bound Complement Activation Products (CB-CAPs), which are much more sensitive than those used by standard lupus tests. 5 Research suggests ours are up to 47% better at detecting lupus compared to anti-dsDNA antibody testing alone. 6 AVISE CTD’s lupus test is the only test on the market that uses patented lupus biomarkers that can help predict whether you will develop lupus. The biomarkers may also help monitor disease progression.5

Use our interactive symptoms checklist to find out if your symptoms could be caused by an autoimmune disease.
Symptoms Checklist
Image
Last reviewed by an Exagen subject expert on 09/09/2022.

References:

  1. National Institutes of Health. Autoimmune Diseases. National Institute of Environmental Health Sciences. Reviewed May 31, 2022. https://www.niehs.nih.gov/health/topics/conditions/autoimmune/index.cfm. Accessed July 18, 2022.
  2. Angum F, Khan T, Kaler J, et al. The prevalence of autoimmune disorders in women: A narrative review. Cureus. 2020;12(5):e8094. doi:10.7759/cureus.8094. Accessed July 19, 2022.
  3. U.S. Department of Health and Human Services. Autoimmune Diseases. Office on Women’s Health. Reviewed February 22, 2021. https://www.womenshealth.gov/a-z-topics/autoimmune-diseases. Accessed July 19, 2022.
  4. Ahn SS, Jung SM, Yoo J, Lee SW, et al. Anti-Smith antibody is associated with disease activity in patients with new-onset systemic lupus erythematosus. Rheumatol Int. 2019;39(11):1937-1944. doi:10.1007/s00296-019-04445-y. Accessed July 22, 2022.
  5. Liang E, Taylor M, McMahon M. Utility of the AVISE Connective Tissue Disease test in predicting lupus diagnosis and progression. Lupus Sci Med. 2020;7(1):e000345. doi:10.1136/lupus-2019-000345. Accessed July 23, 2022.
  6. Putterman C, Furie R, Ramsey-Goldman R, et al. Cell-bound complement activation products in systemic lupus erythematosus: Comparison with anti-double-stranded DNA and standard complement measurements. Lupus Sci Med. 2014;1(1):e000056. doi:10.1136/lupus-2014-000056. Accessed July 22, 2022