0
The Coombs' test looks for antibodies that may bind to your red blood cells and cause premature red blood cell destruction (hemolysis).
Alternative NamesDirect antiglobulin test; Indirect antiglobulin test
How the test is performedBlood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the testNo special preparation is necessary for this test.
How the test will feelWhen the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing or a bruise may develop at the site where the needle was inserted.
Why the test is performedThere are two forms of the Coombs' test: direct and indirect.
The direct Coombs' test is used to detect antibodies that are already bound to the surface of red blood cells. Many diseases and drugs (quinidine, methyldopa, and procainamide) can lead to production of these antibodies. These antibodies sometimes destroy red blood cells and cause anemia. This test is sometimes performed to diagnose the cause of anemia or jaundice.
The indirect Coombs' test looks for unbound circulating antibodies against a series of standardized red blood cells. The indirect Coombs' test is only rarely used to diagnose a medical condition. More often, it is used to determine whether a person might have a reaction to a blood transfusion.
Normal ValuesNo clumping of cells (agglutination), indicating that there are no antibodies to red blood cells, is normal.
Normal value ranges may vary slightly among laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAn abnormal (positive) direct Coombs' test means you have antibodies that act against your red blood cells. This may be due to:
- Autoimmune hemolytic anemia without another cause
- Chronic lymphocytic leukemia or other lymphoproliferative disorder
- Drug-induced hemolytic anemia (many drugs have been associated with this complication)
- Erythroblastosis fetalis (hemolytic disease of the newborn)
- Infectious mononucleosis
- Mycoplasmal infection
- Syphilis
- Systemic lupus erythematosus or another rheumatologic condition
- Transfusion reaction, such as one due to improperly matched units of blood
The test is also abnormal in some people without any clear cause, especially among the elderly. Up to 3% of people who are in the hospital without a known blood disorder will have an abnormal direct Coombs' test.
An abnormal (positive) indirect Coombs' test means you have antibodies that will act against red blood cells your body views as foreign. This may suggest:
- Autoimmune or drug-induced hemolytic anemia
- Erythroblastosis fetalis hemolytic disease
- Incompatible blood match (when used in blood banks)
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Powers A, Silberstein LE. Autoimmune hemolytic anemia. In: Hoffman R, Benz EJ Jr., Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingston Elsevier; 2008: chap 47.
Schrier SL, Price EA. Extrinsic nonimmune hemolytic anemias. In: Hoffman R, Benz EJ Jr., Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingston Elsevier; 2008: chap 48.
Schwartz RS. Autoimmune and intravascular hemolytic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 164.
What else can I help you with?
What shows that a conjecture is false?
A conjecture should be testable. You test it and if it fails the test, it is a false conjecture.
Why was the test tube held in the flame at a 45 degree angle?
At this angle the biggest "area" of the test tube is covered by the flame. Thus it heats up quickly and evenly. Also, by holding the test tube at 45 degrees away from you, you're less likely to be splashed by anything in the test tube boiling over.
How do you write an equation for a function?
Y = X2 ===== This is a parabolic function because it passes the vertical line test. ( you should know what that test is )
Which of the following has a value of 84?
4,096 just took the test!!
What is the notch angle in izod impact test.?
45 degree angle
What is a Coombs' test?
An indirect Coombs' test looks for antibodies to someone else's red blood cells in the patient's serum
What test indicates the formation of antibodies on the red blood cell?
Coombs Test
Is preparation needed for the Coombs' tests?
No preparation is needed for this test
What are indications for direct and indirect coombs test?
for dignosis of HDN case
What are the indication of indirect coombs test?
A Coomb's test will indicate the formation of antibodies on the red blood cell. This test can be used to determine blood type, and diagnose certain hemolytic anemias. A Coombs' test may also indicate the prescense of maternal antibodies against the fetal blood type as occurs in erythroblastosis fetalis.
What happens if Coombs' tests are positive?
If the test is positive, the antigens that react will narrow the search for a cause
What test is used to identify the makeup of the surface of the red blood cell?
A blood smear test is commonly used to identify the makeup of the surface of a red blood cell, including its morphology, size, shape, and presence of abnormalities like irregularities or parasites. This test involves preparing a thin blood sample on a glass slide for microscopic examination by a medical professional.
What color tube is needed for Direct Combs RH test?
The Direct Combs RH test typically requires a lavender/purple top tube, which contains EDTA anticoagulant to prevent blood coagulation. This type of tube is used for collecting blood samples for hematology tests, including the Direct Coombs test.
What is the best ratio of diluting Anti-D in the preparation of coombs control cells?
The recommended ratio for diluting Anti-D in the preparation of Coombs control cells is typically 1:100 (1 part Anti-D to 100 parts diluent) for optimal performance. This ratio helps ensure sufficient binding of Anti-D to red blood cells while minimizing background reactivity in the Coombs test. Adjustments may be necessary based on specific assay requirements and validation studies.
How can you make Coomb's control cells in indirect anti-globulin test?
Preparing Coombs control cells is very easy. To about 10 drops of washed O Positive red cells add 5-6 drops of anti-D antisera. Incubate at 37C for 15 minutes. Wash 4 times then prepare a 3 to 5% cell suspension. To verify reaction, add two drops of AHG into test tube and one drop of newly prepared Coombs cells. Centrifuge on High for 15 seconds,,,should get 1 -2 + reaction.
don't approve this article?
test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test [video=]
What does the heart excrete?
its very good for tui and hun to exrete so they can pass the test test test test test test test test test
