Blood Tests for Autoimmune Diseases

Diagnosing autoimmune diseases can be a lengthy process. In some cases, it can take more than five years to accurately diagnose an autoimmune disease. There is no one test that can diagnose all 80 types of autoimmune diseases.

However, some blood tests can show whether there is an inflammatory process going on in your body, which is a characteristic of autoimmune diseases. This can help point the way to the correct diagnosis. More specialized tests are available to pinpoint the exact disease.

This article discusses the various blood tests that may be ordered to diagnose an autoimmune disease, how they're interpreted, and what information each can provide.

Blood Tests for Autoimmune Diseases - Illustration by Michela Buttignol

Verywell / Michela Buttignol

C-Reactive Protein (CRP)

This test is used to measure the level of CRP, a protein that is produced by the liver and released into the bloodstream in response to inflammation. Changes in CRP levels can show active inflammation in the body caused by autoimmune diseases, a bacterial or fungal infection, or other chronic conditions, such as type 2 diabetes and osteoarthritis.

Interpretation of CRP levels is as follows:

  • Less than 0.3 mg/dL: Normal, which is the level for most healthy adults.
  • 0.3 to 1.0 mg/dL: Normal or minor elevation can be seen in obesity, pregnancy, depression, diabetes, common cold, gingivitis, periodontitis, sedentary lifestyle, smoking, and genetic polymorphisms.
  • 1.0 to 10.0 mg/dL: Moderate elevation indicates systemic inflammation, such as in the case of rheumatoid arthritis, systemic lupus erythematosus (SLE), or other autoimmune diseases, malignancies, myocardial infarction, pancreatitis, and bronchitis.
  • More than 10.0 mg/dL: Marked elevation signals acute bacterial infections, viral infections, systemic vasculitis, and major trauma.
  • More than 50.0 mg/dL: Severe elevation may be caused by acute bacterial infections.

Erythrocyte Sedimentation Rate (ESR)

The ESR test measures how quickly erythrocytes (red blood cells, RBCs) collect at the bottom of a test tube that contains a blood sample. Normally, RBCs settle relatively slowly. A faster-than-normal rate may indicate inflammation in the body. It could indicate an autoimmune disease, infections, cancer, chronic kidney disease, or other inflammatory conditions.

Your healthcare provider may order this test if you have signs of an inflammatory disorder, such as headaches, fevers, weight loss, and joint stiffness. ESR can also be used to detect and monitor autoimmune diseases.

The normal ranges for ESR are:

  • 0 to 15 mm/hr for men under 50
  • 0 to 20 mm/hr for men above 50
  • 0 to 20 mm/hr for women under 50
  • 0 to 30 mm/hr for women above 50
  • 0 to 10 mm/hr for children
  • 0 to 2 mm/hr for infants

A very high ESR could indicate lupus, polymyalgia rheumatica, and rheumatoid arthritis, among others.

Antinuclear Antibodies (ANA)

Antibodies are proteins that your immune system makes to fight foreign substances like viruses and bacteria. But an antinuclear antibody attacks your own healthy cells instead. It's called "antinuclear" because it targets the nucleus (center) of cells.

Therefore, if an ANA test finds antinuclear antibodies in your blood, it may mean you have an autoimmune disorder. However, up to 15% of otherwise healthy people can have a positive low-titer ANA without any underlying autoimmune disease.

Primarily used for diagnosing SLE, this test measures the titer, or level of antibody, and is usually measured just as positive for the presence of antibodies or negative when no antibodies are detected. The presence of ANA does not confirm a diagnosis of SLE, but a lack of ANA makes that diagnosis much less likely.

While ANA is used most often for a lupus diagnosis, these antibodies can sometimes also signal other systemic autoimmune disorders, like rheumatoid arthritis, scleroderma, or Sjögren's syndrome.

About 95% of those with SLE have a positive ANA test result.

Your healthcare provider may order an ANA test if you have signs of an autoimmune disease such as fever, fatigue, a butterfly rash, muscle pain, and joint pain.


Ferritin is the protein that stores iron inside your cells until your body is ready to use it. Iron is required to make red blood cells, which carry oxygen from your lungs to the rest of your body.

Iron is also important for healthy muscles, bone marrow, and organ function. Too little or too much iron in your system can cause serious health problems. Increased levels of ferritin (also known as hyperferritinemia) can be a sign of inflammation, infections, or malignancies, and are characteristics of conditions like Still's disease and hemophagocytic syndrome.

Normal ranges of ferritin include:

  • 20 to 250 ng/mL for adult men
  • 10 to 120 ng/mL for adult women, 18 to 39 years old
  • 12 to 263 ng/mL for women, 40 years old and over

Enzyme-linked Immunosorbent Assay (ELISA)

The ELISA test detects a number of specific antibodies or antigens in a blood sample. Your healthcare provider will have an idea of what condition is causing your symptoms, then test your blood for specific antibodies that can be found in that disease. For example, in the case of rheumatoid arthritis, the ELISA test can be used to look at many markers, including IL-17, rheumatoid factor, and anti-CCP antibodies.

Normal and abnormal ranges will vary based on the antigen being investigated. For some conditions, the detection of a particular antibody may be normal.

Rheumatoid Factor (RF)

The RF test checks for the presence of the rheumatoid factor, a protein produced by the immune system that can attack healthy joints, glands, or cells by mistake. It is usually used to diagnose rheumatoid arthritis, but it can also detect juvenile arthritis, lupus, certain infections like tuberculosis, some types of cancer such as leukemia, and other autoimmune disorders.

For RF, normal ranges are:

  • Less than 15 IU/mL
  • Less than 1:80 for titer levels

About 20% of people with rheumatoid arthritis have a small amount of or no rheumatoid factor in their blood. So even if your results are normal, your healthcare provider may order more tests, like the anti-cyclic citrullinated peptide antibodies test to confirm or rule out rheumatoid arthritis.

Anti-cyclic Citrullinated Peptide (Anti-CCP) Antibodies

Anti-CCP antibodies, also called CCP antibodies, are a type of antibody called autoantibodies. Antibodies and autoantibodies are proteins made by the immune system. A CCP antibodies test measures the level of these autoantibodies. If CCP antibodies are found in your blood, it can be a sign of rheumatoid arthritis.

Results are typically only listed as positive or negative. This test result is usually interpreted along with an RF test result:

  • Positive CCP antibodies and positive RF likely mean that someone has rheumatoid arthritis.
  • Positive CCP antibodies and negative RF may mean someone is in the early stages of rheumatoid arthritis or will develop it in the future.
  • Negative CCP antibodies and negative RF mean a person is less likely to have rheumatoid arthritis. Their provider may need to do more tests to help find out what is causing your symptoms.

CCP antibodies test results can also be reported in one of two ways:

  • Value: Normal less than 15 IU/mL
  • Titer: Normal less than 1:80 (1 to 80)

Normal value ranges may vary slightly among different laboratories.


This test measures the amount of immunoglobulins, also known as antibodies, in your blood. It usually measures three specific types of immunoglobulins: IgG, IgM, and IgA, and sometimes IgE or I gD are measured.

IgA is found in the linings of the respiratory tract and digestive system, as well as in saliva, tears, blood, breast milk, and other body fluids. It protects against bacterial and viral infections. This type of antibody can take time to form after an infection or immunization. IgM is found mainly in the blood and lymph fluid. It is the first antibody the body makes when it fights a new infection.

IgG includes several subtypes. These antibodies are present in healthy people. They may increase in autoimmune diseases, and the distribution of IgG subtypes can vary for people who have an autoimmune disease. IgE is involved In allergic reactions, and IgD is involved In activating B cells, a type of immune cell.

Examples of autoimmune diseases detected with this test include:

Routine Blood Tests

Routine blood work is also a big part of diagnosing autoimmune diseases. Some of the common blood tests your healthcare provider may order include:

  • Basic metabolic panel or comprehensive metabolic panel: These tests measure your body's metabolism, detecting ranges of electrolytes and minerals in your blood. These measurements provide crucial data about how well different organs are functioning and can signal problems with your pancreas, liver, heart, or kidneys. Abnormal results can signal problems like type 1 diabetes and autoimmune hepatitis.
  • Complete blood count: This test can detect abnormalities in red or white blood cells or clotting problems. Abnormal blood cell counts are common in diseases like SLE.
  • Coagulation studies like activated partial thromboplastin time and prothrombin time: These tests check the ability of your blood to clot, and can help detect disorders like antiphospholipid syndrome.

Several other, more routine tests can detect inflammation, but abnormal levels in these tests may not necessarily be a sign of autoimmune disease, including:

  • Fibrinogen: 200 to 400 mg/dL
  • Haptoglobin: 410 to 1,650 mg/L
  • Albumin: 3.4 to 5.4 g/dL

A variety of issues can cause false positive or false negative tests. These include taking certain medications, recent acute illness, injury, recent surgery, and lab error. Interpretation of test results is done with consideration of your symptoms and overall health. Often, tests for autoimmune disease are repeated to see patterns over time—and a test result that doesn't seem right will usually be repeated.

Less Common Autoimmune Tests

To make a more accurate diagnosis, a number of blood tests target specific antibodies or autoimmune markers. Some specific antibody tests that your healthcare provider may recommend include:

  • Anti-double stranded DNA (lupus)
  • Extractable nuclear antigen (lupus, Sjogren's systemic sclerosis, inflammatory myositis, mixed connective tissue disease)
  • Anti-signal recognition particle tests (inflammatory myositis)
  • Anti-neutrophil cytoplasmic antibody (granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, inflammatory bowel disease)
  • Complement complexes (lupus)
  • Cryoglobulins (Raynaud's syndrome)
  • Lupus anticoagulant, anti-cardiolipin or anti-phospholipid autoantibodies (lupus, antiphospholipid syndrome)

A Word From Verywell

Making a diagnosis for an autoimmune disease can be a long and frustrating process. You may need to take multiple blood tests, but these tests don't definitively determine whether you have an autoimmune condition and which condition you have. Talk with your healthcare provider about any symptoms you have, even if you think they are not related to a particular condition. Every symptom is a clue that can help your healthcare provider narrow their differential diagnosis.

17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.