Red Cell Antibody Test: MedlinePlus Medical Test (2023)

What is an RBC antibody test?

The RBC (red blood cell) antibody test is a blood test that looks for RBC antibodies in the blood. These antibodies destroy red blood cells that are different from your own (foreign) blood cells. Having RBC antibodies won't hurt your health, but:

  • If you have αBlood transfusioncan cause serious illness.
  • If you are pregnant, they can harm your baby.

Antibodies are proteins that yoursimmune systemattacks germs and other foreign substances in the body, including some foreign red blood cells. Blood transfusions and pregnancy are two ways to come into contact with foreign red blood cells.

Your immune system responds to foreign red blood cells when they have markers, called antigens, that are different from the antigens on your own cells. Unrecognized antigens stimulate the immune system to produce anti-erythrocyte antibodies to destroy foreign red blood cells.

The RBC antibody test can find these antibodies before they cause health problems.

Other names: antibody test, indirect antiglobulin test, indirect anti-human globulin test, IAT, indirect Coombs test, erythrocyte Ab, erythrocyte antibody identification

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What is it useful for;

The red cell antibody test is used to check your blood for red cell antibodies before a blood transfusion or when you are pregnant:

  • Before a blood transfusion, the test can help determine if donor blood is compatible (good compatibility) with your blood. If your blood has antibodies against the donor's blood, your immune system will attack the red blood cells during the transfusion. This type of immune reaction can cause serious illness. The RBC antibody test helps to compare with blood that will not cause an adverse reaction.
  • During pregnancy, the test can show if you have antibodies against red blood cells which could attack the red blood cells of your unborn baby, causing a very serious type ofanemiato the baby. The antibodies that can cause this problem in pregnancy include Rh antibodies and Kell antibodies.

    The most common cause of anemia in infants isRh incompatibility. The Rh factor is a red blood cell antigen that you inherit from your parents. If you don't have Rh antigens in your blood cells, but your unborn baby does, then you have Rh incompatibility. If your blood mixes with your baby's blood, you will develop antibodies on the red blood cells that attack your baby's blood.

    Early in your pregnancy, and even before you become pregnant, you will haveprenatal blood testto find out if you have the Rh antigen:

    • If you do not have Rh antigens, you are Rh negative.If the baby's biological father is Rh positive (has Rh antigens) or his blood type is unknown, you will be treated as if you and your baby are not Rh-compatible. This is because most people are Rh positive.

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      Normally, Rh incompatibility does not cause problems in the first pregnancy. This is because the body takes time to produce antibodies, and contact with the baby's blood mostly occurs at birth, if at all. But Rh antibodies can cause problems in future pregnancies or if you need a blood transfusion.

      The RBC antibody test checks whether you have developed antibodies that could affect your current or future pregnancy. If you haven't done these, you may be treated to prevent your body from making Rh antibodies.

    • If you have Rh antigens, you are Rh positive.Your immune system willIsdevelop Rh antibodies, so you won't be Rh incompatible. But you can still have an RBC antibody test to look for other less common red cell antibodies that may also affect your baby.

The RBC antibody test can also look for antibodies against Kell antigens. Kell antigens are a group of red blood cell antigens that can trigger a strong immune response if you don't have Kell antigens in your blood.

In most cases, Kell RBC antibodies develop over time after exposure through multiple blood transfusions. But you can also produce Kell RBC antibodies during pregnancy if your baby has Kell antigens and you don't. Kell antibodies can cause very severe anemia, which can be life-threatening to the unborn baby.

Why do I need an RBC antibody test?

Your doctor may order a red blood cell test if you need a blood transfusion or if you are pregnant. RBC antibody testing is usually performed early in pregnancy as part of the routineprenatal examination. If you have Rh-negative blood, you may need another RBC antibody test later in your pregnancy.

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What happens during an RBC antibody test?

The healthcare professional will take a blood sample from a vein in your arm using a small needle. After the needle is inserted, a small amount of blood will be drawn into a test tube or vial. You may feel a slight prick as the needle goes in or out. It usually takes less than five minutes.

Will I need to do anything to prepare for the test?

No special preparation is required for the red blood cell test.

Are there risks associated with the test?

The risk of a blood test is very small. There may be slight pain or bruising where the needle is put in, but most symptoms go away quickly.

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What do the results mean?

If you receive a blood transfusion:The results of the red blood cell test will help you determine the best matching donor blood type:

  • Positive resultmeans that the patient's blood has one or more red cell antibodies that can attack the red cells in certain types of donor blood. You'll probably need more testing to find out exactly what type of RBC antibody you have. This information will help you find donor blood that won't cause your immune system to destroy your red blood cells during a transfusion.
  • Negative resultmeans that no antibodies have been detected in the red blood cells.

If you are pregnant:The RBC screen will show if your blood contains antibodies that could harm your baby.

  • A negative result means no red cell antibodies have been detected.If you have Rh-negative blood, you may be given an injection (injection) to prevent your body from producing Rh antibodies that could harm your current baby or your baby in a future pregnancy.
  • A positive test result means you have red cell antibodies in your blood.You will probably need more tests to find out what red cell antibodies you have.
    • If you have Rh antibodiesyou may have more frequent checkups during your pregnancy to check on your baby's health.
    • If you have other RBC antibodies but no Rh antibodiesYour pregnancy will be closely monitored. If you have Rh-negative blood, you may still receive an injection to prevent your body from producing Rh antibodies, which could harm your baby or babies in future pregnancies.

If you have questions about your results, talk to your doctor.

Learn more aboutlaboratory tests, reference ranges and understanding of results.

Is there anything else I should know about the RBC antibody test?

Rh incompatibility is not common. Most people are Rh positive, which does not cause blood incompatibility and is not a health risk.

Once you have RBC antibodies, they never go away. But you may have very few who show up for the exam. If you've had a red cell antibody test that showed you have red cell antibodies, be sure to tell your doctor, especially if you need a blood transfusion or are pregnant.

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  1. ACOG: American Congress of Obstetricians and Gynecologists [Internet]. Washington DC: American Congress of Obstetricians and Gynecologists. c2022. Rh factor: how can it affect pregnancy? June 2020 [cited April 11, 2022]; [about 3 screens]. Available from:
  2. American Pregnancy Association [Internet]. Irving (TX): American Pregnancy Association; c2021. Rh factor? [quoted April 11, 2022]? [about 9 screens]. Available from:
  3. American Society of Hematology [Internet]. Washington DC: American Society of Hematology; c2022. Glossary of Hematology; [quoted April 11, 2022]? [about 5 screens]. Available from:
  4. ClinLab Navigator [Internet]. ClinLabNavigator; c2022. Prenatal Immunohematology Testing [cited April 11, 2022]. [about 9 screens]. Available from:
  5. CS Mott Children's Hospital [Internet]. Ann Arbor (MI): Regents of the University of Michigan. c1995-2022. Coombs antibody test? [accessed September 23, 2020; cited on April 11, 2022]; [about 2 screens]. Available from:
  6. Dean L. Blood groups and erythrocyte antigens [Internet]. Bethesda (MD): National Center for Biotechnology Information (USA). 2005. Chapter 2, Blood group antigens are surface markers on the membrane of red blood cells. [about 5 screens]. Available from:
  7. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; around 1998–2022. Tests and procedures: Rh factor blood test. [quoted April 11, 2022]? [about 5 screens]. Available from:
  8. National Heart, Lung and Blood Institute [Internet]. Bethesda (MD): United States Department of Health and Human Services. BLOOD TESTS; [updated on March 24, 2022, cited on April 11, 2022] [about 7 screens]. Available from:
  9. NorthShore University Health System [Internet]. NorthShor University Health System; c2022. Blood types [quoted Apr 11, 2022]? [about 3 screens]. Available from:
  10. Task Diagnostics [Internet]. task diagnostics; around 2000–2022. Clinical Education Center: ABO Group and Rh Type [cited April 11, 2022]. [about 3 screens]. Available from:
  11. [Internet]. Seattle (Washington): OneCare Media; c2022. Blood group determination? [modified November 9, 2021; cited April 11, 2022]; [about 10 screens]. Available from: typing/
  12. [Internet]. Seattle (Washington): OneCare Media; c2022. Vocabulary: Antigen; [quoted April 11, 2022]? [about 10 screens]. Available from:
  13. [Internet]. Seattle (Washington): OneCare Media; c2022. Red blood cell (RBC) antibody test. [modified November 9, 2021; cited April 11, 2022]; [about 9 screens]. Available from:
  14. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2022. Health Encyclopedia: Red Blood Cell Antibody [cited April 11, 2022]; [about 3 screens]. Available from:
  15. University of Warsaw Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Administration; c2022. Health Information: Blood Type Testing [updated June 17, 2021, cited April 11, 2022] [approximately 3 screens]. Available from:


Red Cell Antibody Test: MedlinePlus Medical Test? ›

An RBC (red blood cell) antibody screen is a blood test that looks for RBC antibodies in your blood. These antibodies destroy red blood cells that are different from your own (foreign). Having RBC antibodies won't harm your health, but: If you have a blood transfusion, they could cause serious illness.

What does a positive red cell antibody screening mean? ›

A positive test means you already have antibodies in your blood. If they're Rh antibodies, the shot won't help. Your doctor will watch you and your baby closely. If there are problems while you're pregnant, your baby may need to be born early or get a blood transfusion through the umbilical cord.

What blood tests detect autoimmune antibodies? ›

What is an ANA (Antinuclear Antibody) Test? An ANA test is a blood test that looks for antinuclear antibodies in your blood. Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria. But an antinuclear antibody attacks your own healthy cells instead.

What does a positive antibody test tell you? ›

A positive test means you have COVID-19 antibodies in your blood. A positive result shows past infection with the virus. It's possible to have a positive test result even if you've never had any COVID-19 symptoms.

Is a positive ANA test serious? ›

Living with ANA

One positive ANA test result is not a sure sign of autoimmune disease, so you may not need any immediate treatment. Lab levels vary. Some autoantibodies are normal, so your positive result may not indicate any problem.

How do you get rid of antibodies in your blood? ›

You may need special treatments such as plasmapheresis and/or intravenous immunoglobulin (IVIG) to undergo this type of transplant. These are treatments that can remove antibodies. In select situations, positive crossmatch kidney transplantation is a better option than remaining on the deceased donor waiting list.

Why would a person have anti Rh antibodies present in their blood? ›

Antibodies to RhD develop only after an individual is exposed to RhD antigens via transfusion, pregnancy or organ transplantation. Anti RhD (or anti-D) antibodies destroy RhD positive red cells and can lead to haemolytic transfusion reactions.

What are 5 common symptoms of an autoimmune disorder? ›

Common Autoimmune Disease Symptoms
  • Fatigue.
  • Joint pain and swelling.
  • Skin problems.
  • Abdominal pain or digestive issues.
  • Recurring fever.
  • Swollen glands.

Which test confirms autoimmune disease? ›

One blood test for autoimmune disease is C-reactive protein (CRP). Another test is ESR (erythrocyte sedimentation rate) - this is done to assess an inflammation that is not from an infection or due to other reasons. One of the most common blood tests for detecting autoimmune disorders is ANA (antinuclear antibodies).

What antibodies show lupus? ›

Antinuclear antibody (ANA) autoantibodies, or antibodies produced by the immune system that attack the body's own cells, are a hallmark of lupus. ANA is usually measured as 0 to 4+ or as a titer (the number of times a blood sample can be diluted and still be positive).

What is the best blood test for the immune system? ›

An immunoglobulins blood test measures the amounts of IgM, IgG, and IgA in your blood to help diagnose different types of health conditions that may affect your immune system.

What does antibodies in blood mean? ›

The presence of antibodies in the blood indicates a recent or past infection. Antibody levels also indicate the strength of the immune response to an infection or autoimmune disease.

What is the antibody test for Hashimoto's? ›

A thyroid antibodies test usually measures one or more of the following types of antibodies: Thyroid peroxidase antibodies (TPO). These antibodies can be a sign of: Hashimoto disease, also known as Hashimoto thyroiditis.

What cancers cause positive ANA? ›

ANA positivity has been described in malignant disease, not just in lung cancer, but also in breast and colon cancer, and in lymphoproliferative disorders. 23 A study published by Solans-Laque et al., showed that 27.7% of the patients diagnosed with cancer, had positive ANA, with titers ranging from 1:80 and 1:640.

What cancers are associated with high ANA? ›

Neoplastic diseases may cause positive ANA. Some authors have described that ANA is found in the sera from lung, breast, head and neck cancer patients as frequently as in RA and SLE 3, 4, 5. Chapman et al. 6 has suggested that in breast cancer they may be used as an aid to early diagnosis.

What is the next step after a positive ANA test? ›

So if you have a positive ANA, don't panic. The next step is to see a rheumatologist who will determine if additional testing is needed and who will make sure you will get the best care for your particular situation.

What diseases cause antibodies in blood? ›

They include:
  • Lupus.
  • Rheumatoid arthritis.
  • Sjogren's syndrome.
  • Thyroid disease.
  • Ulcerative colitis.
  • Hashimoto's disease.
Jan 31, 2022

What autoimmune disease causes high red blood cell count? ›

Evans syndrome is an autoimmune disorder. It occurs when the immune system produces antibodies that mistakenly attack healthy tissue, specifically red blood cells, platelets and sometimes certain white blood cells.

How did I get antibodies in my blood? ›

These antibodies may have formed from a blood transfusion, from an earlier pregnancy, or even from exposure to some viruses or bacteria. If your fetus has a different blood group than yours, your immune system may also make antibodies against that "foreign" blood group.

What blood type has Rh antibodies? ›

If your blood type is positive, then your blood cells have the Rh protein. If your blood type is negative, then your blood cells lack the Rh protein.

Is Rh an autoimmune disease? ›

Rheumatoid arthritis is an autoimmune disease. Normally, your immune system helps protect your body from infection and disease. In rheumatoid arthritis, your immune system attacks healthy tissue in your joints. It can also cause medical problems with your heart, lungs, nerves, eyes and skin.

What is the hardest autoimmune disease to diagnose? ›

Some common autoimmune diseases, including Type 1 diabetes mellitus, are relatively easy to diagnose, while others, such as vasculitis, Addison's disease, lupus, and other rheumatic diseases, are more difficult. Additionally, many of the 100-plus autoimmune diseases are uncommon or rare.

What vitamins should autoimmune patients avoid? ›

Avoid high doses of vitamin C, beta carotene, cat's claw, echinacea and ginseng, among others. Why add fuel to the fire? Doing so may cause you to slip out of remission and into more misery. I'll share some tips in the space provided, but there are so many other nutrients.

What are the top 3 autoimmune diseases? ›

Top Autoimmune Conditions and Diseases
  • Celiac Disease.
  • Sjögren's Syndrome.
  • Scleroderma.
  • Multiple Sclerosis (MS)
  • Systemic Lupus Erythematosus.

What is the first test for autoimmune disease? ›

Immunofluorescence is particularly useful as an initial screening test for those individuals suspected of having an autoimmune disease – SLE, Sjögren's syndrome, RA, mixed connective tissue disease (MCTD), scleroderma, polymyositis/dermatomyositis (PM/DM).

What is the most sensitive test for autoimmune? ›

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.

What is the most common autoimmune test? ›

One of the most commonly ordered tests is the antinuclear antibody (ANA) test. ANA may be positive with a variety of autoimmune diseases, including lupus, Sjögren syndrome, rheumatoid arthritis, and autoimmune hepatitis. When someone has a positive ANA, other autoantibody tests are used to help make a diagnosis.

What does lupus look like in blood work? ›

A low white blood cell or platelet count may occur in lupus as well. Erythrocyte sedimentation rate. This blood test determines the rate at which red blood cells settle to the bottom of a tube in an hour. A faster than normal rate may indicate a systemic disease, such as lupus.

What determines if a red blood cell antibody is clinically significant? ›

Transfusion specialists have varied definitions of a “clinically significant antibody.” The clinical significance of antibodies to red cell antigens is usually judged by their capacity to shorten red cell survival by causing hemolytic transfusion reactions (HTR) or through their association with hemolytic disease of ...

What does it mean to be Rh positive? ›

Rh factor is a protein that's found on some people's red blood cells. If your red blood cells have the protein, you're Rh-positive. If your red blood cells don't have the protein, you're Rh-negative. Being Rh-positive or Rh-negative doesn't affect your health.

Is a high RBC count good or bad? ›

An RBC count that is higher than normal can be a sign of many health problems, including: Dehydration. Lung diseases. Heart diseases.

How long does RhoGAM cause positive antibody screen? ›

Once RhoGAM is given, an antibody screen can return positive, detecting a positive anti-D antibody for several months following administration.

What is abnormal red cell antibodies? ›

This could be in response to an infection, vaccination or transfusion of blood. In your case, an antibody has been produced against an antigen on certain different blood cells – these are called irregular red cell antibodies. These antibodies are not caused by infection or illness.

What is the most common red cell antibody? ›

Normally, anti-A and anti-B are the only red cell antibodies present in human plasma and known as naturally occurring antibodies. All other antibodies are known as unexpected red cell antibodies because these require immune exposure for development (pregnancy, transplant or blood transfusion)2.

What is the significance of red blood cell test? ›

The results of an RBC count can be used to help diagnose blood-related conditions, such as iron deficiency anaemia (where there are less red blood cells than normal). A low RBC count could also indicate a vitamin B6, B12 or folate deficiency.

Is it better to be Rh positive or negative? ›

Although Rh positive is the most common blood type, having a Rh-negative typing does not indicate illness and usually doesn't affect your health.

What are the symptoms of Rh disease? ›

What are the symptoms of Rh disease?
  • Yellow coloring of the skin and whites of the eyes (jaundice)
  • Pale-coloring because of anemia.
  • Fast heart rate (tachycardia)
  • Fast breathing (tachypnea)
  • Lack of energy.
  • Swelling under the skin.
  • Large abdomen.

Is it good or bad to be Rh positive? ›

The positive or negative next to the blood type is your Rh factor. Your Rh factor doesn't cause problems or hurt your health in any way. It only becomes important when blood types are mixed together, like during pregnancy and childbirth.

What cancers cause high red blood cell count? ›

Overview. Polycythemia vera (pol-e-sy-THEE-me-uh VEER-uh) is a type of blood cancer. It causes your bone marrow to make too many red blood cells. These excess cells thicken your blood, slowing its flow, which may cause serious problems, such as blood clots.

How do you fix high RBC count? ›

High RBC Count Treatment
  1. Exercise to improve your heart and lung function.
  2. Eat less red meat and iron-rich foods.
  3. Avoid iron supplements.
  4. Keep yourself well hydrated.
  5. Avoid diuretics, including coffee and caffeinated drinks, which can dehydrate you.
  6. Stop smoking, especially if you have COPD or pulmonary fibrosis.
Oct 14, 2022

What conditions cause high RBC count? ›

Higher than normal numbers of RBCs may be due to: Bone marrow disease that causes abnormal increase in RBCs (polycythemia vera) Cigarette smoking. Dehydration (for example, from severe diarrhea)

Do Rh antibodies go away? ›

Periodic Rh antibodies were carried out over a period of one to four years in a series of 60 sensitized Rh-negative individuals. The results indicate that once an individual has become sensitized to the Rh factor, the antibodies persist in his body for the remainder of his life.

What blood types should not have babies together? ›

When a mother-to-be and father-to-be are not both positive or negative for Rh factor, it's called Rh incompatibility. For example: If a woman who is Rh negative and a man who is Rh positive conceive a baby, the fetus may have Rh-positive blood, inherited from the father.

Is a negative antibody test good? ›

If your antibody test is negative, it means that we have not detected antibodies to the virus that causes COVID-19 in your blood. This could mean: You have not been exposed to the virus that causes COVID-19 (novel coronavirus) You have levels of antibodies too low for us to detect.


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