Irregular Antibody Screening

Clinical information

Diagnostic Utility:

• This test detects the presence of anti-erythrocyte antibodies in plasma/serum. These antibodies may develop after exposure to erythrocyte antigens that the individual does not possess, as a result of pregnancies, transfusions, or previous transplants.
• Irregular antibodies can cause haemolytic disease of the newborn, transfusional haemolytic reactions, or rejection reactions after a transplant. That is why they are investigated in all pregnant women and before carrying out a transfusion or a transplant.
• However, studies of haemolytic disease of the newborn, maternal-fetal incompatibility, and studies of possible transfusional haemolytic reactions or rejection systematically include the determination of irregular antibody screening.

Method: 

Indirect antiglobulin technique (indirect Coombs).

The problem plasma/serum is exposed to a panel generally consisting of 3 red blood cells expressing different antigens to detect clinically significant irregular antibodies.

Reference Values

Possible results are: Negative, Positive.

Diagnostic Algorithm:

In case of a positive screening, test 0011 Irregular Antibody Identification is generated. In pregnant women and in some patients where it may be of interest, test 4918 Irregular Antibody Titration is also generated.

*Although these tests can be requested separately, the laboratory needs to know that the sample contains an antibody and its specific specificity in order to perform the titration. That is why an Antibody Screening (if Identification is requested) and a Screening or, at least, an Identification (if titration is requested) will always be carried out initially.

Response Time:

1 day when the screening is negative.
1 day when the screening is positive and the identification is unequivocal.
Several days may be required when the identification is complex (antibody mixtures or uncommon specificities).

Specimen information

Sample: Whole blood
Tube: EDTA K3 10 ml tube
Minimum volume: 6 ml
Stability:

• At room temperature: 4 days
• In refrigeration: 4 days

Transport instructions: Preferably at room temperature

Reason for rejection: Highly hemolyzed sample

Administrative information

BST Code: 0010
Test Description: Irregular antibody screening
Synonyms: Indirect antiglobulin test, Indirect Coombs
Section: Immunohematology
BST Rate: Check updated rates by clicking here.

Profiles:

Test 0010 Irregular antibody screening can be requested individually. It is also performed within the following profiles:

References

AABB Technical Manual. 19th edition. Editat per MK Fung, AF Eder, SL Spitalnik, CM Westhoff: AABB 2017