Antibody Investigation

Clinical Background:

Request Reasons: The laboratory will request an antibody investigation when a positive reaction is detected in the antibody screen. Blood group antibodies of the ABO system are universally common, but those of other blood group systems are only produced when red cells are transferred to a patient via a blood transfusion or a fetal red cell bleed during pregnancy. Theoretically, any antigen present on the transferred red cells which are not also present on the patient’s own red cells may be recognised as foreign by the recipient’s immune system and produce (atypical) antibodies. However, this does not routinely occur and antibody stimulation is dependent on a number of factors including the immunogenicity of the antigen involved. Rarely, these occur ‘naturally’ without a stimulus and are sometimes auto-antibodies i.e. directed against the patient’s own red cells. When an atypical antibody is detected (antibody screen) it must be identified to allow for provision of compatible blood. This is especially true of antibodies that are ‘clinically significant’, these antibodies are capable of causing either transfusion reaction and/or haemolytic disease of the fetus or newborn (HDFN). Where it is not possible to identify the antibody (or antibodies) present the samples may require referral to an NHSBT reference laboratory. Blood group antibodies are only important to the patient when they require a blood transfusion or are pregnant.

Discipline:

Transfusion

Transfusion
Specimen Container Adult:

6mL K2 EDTA (Pink Top)

6mL K2 EDTA (Pink Top)
Specimen Container Paediatric:

6mL K2 EDTA (Pink Top)

6mL K2 EDTA (Pink Top)
Minimum Volume Adult:

6mL

6mL
Minimum Volume Paediatric:

2mL

2mL
Special Requirement:

Sample must be HANDWRITTEN and contain the patient's details

Sample must be HANDWRITTEN and contain the patient's details
Sample Stability:

Short term storage: 24 hours at Room Temperature. Long term storage: 7 days at 4-6

Short term storage: 24 hours at Room Temperature. Long term storage: 7 days at 4-6
Transport Requirements:

Sample should be transported to Laboratory Medicine Reception via GP courier, hospital air-tube system or hand delivered to maintain storage conditions. Samples must not be subjected to extreme hot...

Sample should be transported to Laboratory Medicine Reception via GP courier, hospital air-tube system or hand delivered to maintain storage conditions. Samples must not be subjected to extreme hot or cold conditions prior to testing.
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Add On Test:

Requested as required by the laboratory. DAT Eluate Phenotype Molecular Genotype Reference Referral

All urgent add ons via telephone must be confirmed via email to the appropriate email address

tnu...

Requested as required by the laboratory. DAT Eluate Phenotype Molecular Genotype Reference Referral

All urgent add ons via telephone must be confirmed via email to the appropriate email address

tnu-tr.bloodsciencesadditions@nhs.net (internal)

tnu-tr.bloodsciencesadditions@nhs.net (external)
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Interpretation:

The presence or absence of antigens and antibodies is identified by agglutination. Agglutination occurs when the red cells are cross-linked by the binding of either IgG or IgM antibody molecules. T...

The presence or absence of antigens and antibodies is identified by agglutination. Agglutination occurs when the red cells are cross-linked by the binding of either IgG or IgM antibody molecules. The pattern of reactions against a panel of reagents with known antigen or antibody status is used identify the antibodies or antigens present. The pattern of reactions against a panel of reagents with known antigen status is used identify the antibody (or antibodies) present. The report will state the patient’s Blood Group and indicate whether alloantibodies are present or not. The samples may require referral to an NHSBT reference laboratory depending on classification and thermal amplitude of the antibody. Once the investigation to identify clinically significant allo and/or auto antibodies is complete the laboratory can provide compatible antigen negative blood for transfusion.
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Factors Affecting Result:

Key factors affecting the result: • Incorrect specimen type received • Clotted, haemolysed, icteric or lipaemic samples • Insufficient plasma provided • Clotted samples may interfere with instrumen...

Key factors affecting the result: • Incorrect specimen type received • Clotted, haemolysed, icteric or lipaemic samples • Insufficient plasma provided • Clotted samples may interfere with instrument pipetting and must not be used. • Fibrin or particulate matter, clots, bubbles or scratches can interfere with reaction interpretations.
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Referenced Documents:

4/1/15

4/1/15
Routine Contact Name:

Section Leader:
Routine Telephone:

Freeman: 0191 213 7849
RVI: 0191 282 4335

Freeman: 0191 213 7849
RVI: 0191 282 4335
Specialist Test:

Yes

Yes
Specialist Contact Name:

transfusion manager

transfusion manager
Specialist Telephone:

0192 213 9169

0192 213 9169

Antibody Investigation

Clinical Background:

Test Details

Availability:

Turn Around: