When an antibody screen test, performed by a Blood Bank, is positive it must be investigated to determine if there are clinically significant antibodies present. The antibody identification procedure for Blood Bank is performed after a positive antibody screen is detected, to identify what the unexpected antibody or antibodies may be in the patient’s plasma. It is essential to identify and evaluated the significance of the antibody or antibodies identified for transfusion candidates to prevent a hemolytic transfusion reaction and to identify obstetrical patients with alloantibodies which might cause hemolytic disease of the newborn.
Useful For
To detect unexpected antibodies in pretransfusion candidates and to identify obstetrical patients with alloantibodies that may cause hemolytic disease of the newborn. Identification of antibodies to red cell antigens detected in pretransfusion antibody screening requires testing the patient’s plasma against a panel of red cell samples with known antigenic composition. The antibody identification panel are performed and interpreted by blood bank technical staff to identify if a clinically significant antibody is present. When an individual produces an antibody to an antigen they lack, the antibody is called an alloantibody. When an individual produced antibody to an antigen they posses, this is called an autoantibody. Immunization to red cell antigens may result from exposure to red cells for example, from pregnancy or previous transfusion. The antibody screen is a blood bank test used to detect whether or not a patient has any unexpected antibodies. An additional test, called antibody identification, is then performed after a positive antibody screen to determine the degree of clinical significance of the positive antibody screen. A clinically significant antibody is defined as an antibody that is associated with hemolytic disease of the fetus and newborn (HDFN), hemolytic transfusion reactions, or a notable decrease in transfused red cell survival.
Method Name
Hemagglutination (Tube and Gel Methods)
- Primary method is Gel.
Important Note
A pending antibody identification test in a patient may cause a delay in blood product availability as the antibody identification panel is investigated and evaluated for its clinical significance.
Aliases
Antibody Identification, AB ID, ABID, Antibody ID, Clinically Significant Antibodies, Antibody Titer
Specimen Type
Whole Blood
Specimen Required
Large lavender-top (EDTA) tube, approximately 7 mL.
NOTE: If the antibody identification is a complicated work up, additional samples may be required.
If the patient has a history of a complicated antibody identification please drawn two (2) Large lavender-top (EDTA) tube, approximately 7 mL in case the sample needs to be sent to the reference lab for further testing.
After the patient is positively identified, the sample is drawn and fully labeled with the following information either electronically or handwritten:
- Patient’s full First and Last Name
- Date of Birth or Medical Record Number (MRN#)
- Date and Time specimen was drawn
- Blood Bank Armband Number (BBID) (see below for more information)
- Identify of the person who collected the specimen (Ex: Cerner ID or personnel initials)
All inpatients, or patients potentially receiving a transfusion, must have a blood bank armband (BBID) applied to their wrist and the Blood Bank ID (BBID) number written on the tube. This blood bank armband is a secondary patient identifier that helps ensure a safe and accurate transfusion. Specimens received without a blood bank armband will be rejected. See special instructions for more information.
Specimen Minimum Volume
1.0 – 4.0 mL
NOTE: If the antibody identification is a complicated work up or the patient has a history of a complicated antibody workup, additional samples may be required. If the patient has a history of a complicated antibody identification please drawn two (2) Large lavender-top (EDTA) tubes in case the sample needs to be sent to the reference lab for further testing.
Specimen Stability Information
Stable at room temperature for 24 hours.
Rejected Due To
- If the patient’s full first and last name and date of birth are not clear, accurate, and/or readable the specimen must be rejected.
- If the Blood Bank Armband Number (BBID) from the Blood Bank Armband is missing, inaccurate, illegible and/or can not be confirmed on all inpatient and outpatient potential transfusion specimens, the specimen must be rejected and sample redrawn.
- Specimens may be rejected for insufficient quantity and/or quality reasons (Ex: Hemolysis, dilution, etc).
- If there is any doubt as to the identity of the sample, a new sample must be obtained.
- If a specimen is rejected on a trauma, OR, or other critical patient when blood is needed urgently/immediately, have the specimen redrawn in accordance with this policy and follow the policy “Issue of Blood in Urgent Situations”. Uncrossmatched blood can still be given in an emergent situation.
- In the case of a positive antibody screen or history of an antibody, the Provider must evaluate the necessity of blood urgently as the uncrossmatched blood released may be incompatible and may cause a hemolytic transfusion reaction.
Special Instructions
The person drawing the blood sample must confirm the patient’s identity by checking at least two independent identifiers before collected a specimen such as: first name, last name, date of birth, and medical record number. If possible, patient identification should be obtained verbally directly from the patient. The phlebotomist must not rely on a bed tag or on charts or records placed nearby. After positively identifying the patient, the sample is drawn and fully labeled with the following information either electronically or handwritten: Patient’s full first and last name, date of birth or medical record number (MRN#), date and time specimen was drawn, Blood Bank Armband Number (see below for more information), and identify of the person who collected the specimen (Ex: Cerner ID or personnel initials).
All inpatients, or patients potentially receiving a transfusion, must have a Blood Bank Armband applied to their wrist and the Blood Bank Armband Number (BBID) number written on the tube. Please write the number clearly and do not use a gel pen (anything written in gel pen smears as the specimen is transported in a bag to the lab). This blood bank armband is a secondary patient identifier that helps ensure a safe and accurate transfusion. Specimens received without a blood bank armband ID will be rejected.
Performing Laboratory
Glens Falls Hospital Laboratory
If sample needs to be sent out for further testing the sample will be processed at a reference lab.
- Primary reference lab is the American Red Cross West Henrietta, NY
Reference Values
See attached report for clinically significant antibody identified. A clinically significant antibody is defined as an antibody that is associated with hemolytic disease of the fetus and newborn (HDFN), hemolytic transfusion reactions, or a notable decrease in transfused red cell survival.
A nonspecific antibody may be identified. Reactions are present in the patient’s plasma but all clinically significant antibodies are ruled out.
An inconclusive result is for patient specimens that need to be sent to the reference lab for further workup. See attached report for reference laboratory findings when available.
Day(s) and Time(s) Performed
24 hours 7 days a week
Analytical Time
STAT turn around time approximately 1 hour.
Routine inpatient samples around time is approximately 2- 4 hours.
Routine outpatient samples to 1-2 days.
- If an antibody identification test can not be completed at the hospital, for example due to a complicated work up and limited resources, the sample may be sent to a reference lab for further workup to determine what is causing the patient’s positive antibody screen. This is essential to determine whether or not there are clinically significant antibodies.
- Turn around time is dependent on when the specimen arrives to the lab and can be sent to the reference lab in West Henrietta, NY
- STAT Reference Lab turn around time is approximately 24 hours.
- Routine Reference Lab turn approximately around time is 2-4 days.
- Turn around time is dependent on when the specimen arrives to the lab and can be sent to the reference lab in West Henrietta, NY
Specimen Retention Time
1o days
Reflex Tests
Antibody Identification work ups that can not be completed at Glens Falls Hospital Blood Bank may be sent to the reference lab (American Red Cross Reference Lab in West Henrietta, NY) for additional workup.
Analytical Time
STAT turn around time approximately 1 hour.
Routine inpatient samples around time is approximately 2- 4 hours.
Routine outpatient samples to 1-2 days.
- If an antibody identification test can not be completed at the hospital, for example due to a complicated work up and limited resources, the sample may be sent to a reference lab for further workup to determine what is causing the patient’s positive antibody screen. This is essential to determine whether or not there are clinically significant antibodies.
- Turn around time is dependent on when the specimen arrives to the lab and can be sent to the reference lab in West Henrietta, NY
- STAT Reference Lab turn around time is approximately 24 hours.
- Routine Reference Lab turn approximately around time is 2-4 days.
- Turn around time is dependent on when the specimen arrives to the lab and can be sent to the reference lab in West Henrietta, NY