Isohaemagglutinins

Clinical Background:

Isohaemagglutinin titres are performed as an indicator of immune competence for a variety of clinical conditions e.g. SCID, immune deficiency, BMT, solid organ transplant and in preparation of a patient undergoing an ABOi solid organ transplant. Isohaemagglutinins are mainly of the IgM class, although IgG antibodies may also be detected, and are the naturally occurring antibodies of the ABO blood group system anti-A and anti-B. Individuals who are of the AB blood group lack isohaemagglutinins so the test will not be performed on this blood group. Anti-A and anti-B can normally be detected after the first 4-6 months of life, although titres are very low up to 1 year of age. The antibody production increases to reach normal adult levels between 5-10 years of age and may decline in later life. The presence of high titres of IgG isohaemagglutinins in IVIg has been associated with significant haemolysis in isolated case reports. Where high doses are to be used, it may be appropriate to titre the IVIg and rule out high titre batches for clinical use in at risk patients. The isohaemagglutinin titre is a semi quantitative method used to determine the concentration of antibody by testing serial doubling dilutions of serum or plasma against selected red blood cells. Results are expressed as the reciprocal of the highest dilution that causes agglutination.

Discipline:

Transfusion

Transfusion
Specimen Container Adult:

6mL K2 EDTA

6mL K2 EDTA
Specimen Container Paediatric:

6mL K2 EDTA

6mL K2 EDTA
Minimum Volume Adult:

6mL

6mL
Minimum Volume Paediatric:

2mL

2mL
Special Requirement:

Test can be ordered via EPR PowerChart and taken with the BloodTrack bedside sample labelling system.
The Trust operates a zero tolerance policy. Deviation from Trust Sample Labelling Policy will re...

Test can be ordered via EPR PowerChart and taken with the BloodTrack bedside sample labelling system.
The Trust operates a zero tolerance policy. Deviation from Trust Sample Labelling Policy will result in the sample being rejected and a repeat requested.
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Sample Stability:

Short term storage: 24 hours at room temperature.
Long term storage: 7 days at 4-6°C

Short term storage: 24 hours at room temperature.
Long term storage: 7 days at 4-6°C
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:

Request for add on must be discussed directly with the Transfusion laboratory.
FH: 0191 2237849
RVI: 0191 2824435

Request for add on must be discussed directly with the Transfusion laboratory.
FH: 0191 2237849
RVI: 0191 2824435
Interpretation:

The Isohaemagglutinin titre is reported as the highest dilution to give a macroscopic agglutination reaction subject to satisfactory control results. The absence of agglutination, when the patient&...

The Isohaemagglutinin titre is reported as the highest dilution to give a macroscopic agglutination reaction subject to satisfactory control results. The absence of agglutination, when the patient’s diluted plasma is tested against appropriate red cells, indicates that anti-A and/or anti-B are not detectable. Results are expressed as the reciprocal of the highest dilution that causes agglutination (e.g. 1/4, 1/64 etc.)
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Factors Affecting Result:

Insufficient plasma/serum or haemolysed specimen may give incorrect result. High haematocrit can cause insufficient plasma for testing. Technical variables affect results and care should be taken t...

Insufficient plasma/serum or haemolysed specimen may give incorrect result. High haematocrit can cause insufficient plasma for testing. Technical variables affect results and care should be taken to achieve a uniform practice.

Careful pipetting is essential

Optimum time and temperature must be consistent

Age, phenotype and concentration of test cells will influence results

For reproducibility of results comparisons with previous tested samples should be performed concurrently when available.

Measurements are more accurate with large volume dilutions than with small volumes.
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Referenced Documents:

4/19/15

4/19/15
Routine Contact Name:

FH Section Leads
RVI Section Leads
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

Isohaemagglutinins

Clinical Background:

Test Details

Availability:

Turn Around: