Reasons, Procedure & Test Results of Direct Antiglobulin Test

Submitted on March 27, 2012

Hemolytic anemia is a condition in which the red blood cells within the human body are destroyed at a speed greater than with which they are adequately replaced. A direct antigloblin test, also known as a DAT, is primarily used to help determine if the main cause of the condition are the antibodies attached to the red blood cells.

Under normal circumstances, red blood cells will survive for a period of about 4 months before they are naturally replaced by the body’s internal systems. In severe cases of Hemolytic anemia, this timeframe could be shortened to as little as a span of only a few days. The significant lack of red blood cells results in a diminished supply of oxygen to the tissues to various parts of the body. The most noticeable symptoms of the condition include weakness or a general feeling of malaise and a lack of energy. The most common causes of the condition include hereditary, where a gene or genes are passed on from one generation to another within the same bloodline – resulting in the abnormal functioning of the red blood cells or hemoglobin. The condition could also be acquired when an individual is affected by common instances such as autoimmune disorders, transfusion reactions, or even the use of certain drugs or medication that are known to trigger the body to produce antibodies directed against red blood cells.

Reasons for Direct Antiglobulin Test

A direct antiglobulin test is usually ordered when you experience symptoms such as fatigue, dark urine, unusual paleness or an enlarged spleen. Newborns may also be subject to a direct antiglobulin test when they show symptoms such as a swelling of the entire body or difficulty in breathing in addition to the previously mentioned symptoms.


The direct antiglobulin test procedure is conducted by drawing out some amount of blood from the patient, usually extracted from the arm, just behind the elbow. The test is conduced on this sample of blood obtained from the patient. While there is no specific preparation required prior to providing the blood sample, you should make it a point to inform your doctor about any medication, prescription or non prescription drugs that you may be consuming, as this may affect the readings of the blood test.

Test Results

A positive result would mean that there are antibodies attached to the red blood cells. The greater the positive value of the direct antiglobulin test, the higher the amount of antibodies bound to the red blood cells.