Newcastle Laboratories

Isohaemagglutinins

Clinical Background:

Request Reasons: 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 pr...

Request Reasons: 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 ABO mismatch 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 1year 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.

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Test Details

  • Discipline:

    Transfusion

    Transfusion

  • Specimen Container Adult:

    6mL K2 EDTA (Pink Top)

    6mL K2 EDTA (Pink Top)

  • Specimen Container Paediatric:

    0.5mL K2 EDTA (Pink Top) or 6mL K2 EDTA (Pink Top)

    0.5mL K2 EDTA (Pink Top) or 6mL K2 EDTA (Pink Top)

  • Minimum Volume Adult:

    6mL

    6mL

  • Minimum Volume Paediatric:

    2mL

    2mL

  • Special Requirement:

    Ensure good specimen volume to provide sufficient plasma quantity. Samples should idealy be HANDWRITTEN and contain the patient

    Ensure good specimen volume to provide sufficient plasma quantity. Samples should idealy be HANDWRITTEN and contain the patient

  • 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:

    Group and Screen DAT

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

    RVIadditions.Laboratory@nuth.nhs.uk (internal)

    tnu-tr.bloodsciencesadditions@nhs.ne...

    Group and Screen DAT

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

    RVIadditions.Laboratory@nuth.nhs.uk (internal)

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

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  • 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 ...

    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:

    Section Leader:

  • Routine Telephone:

    Freeman: 0191 213 7849
    RVI: 0191 282 43435

    Freeman: 0191 213 7849
    RVI: 0191 282 43435

  • Specialist Test:

    Yes

    Yes

  • Specialist Contact Name:

    transfusion manager

    transfusion manager

  • Specialist Telephone:

    0192 213 9169

    0192 213 9169

Availability:

Routine core hours Only. Please discuss with Haematology Consultant if required outside of core hours unless previously agreed protocol (e.g. during ABO Mismatched Transplant).

Turn Around:

4 hours

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