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Hb H Inclusion Bodies

Container:

Hb H Inclusion Bodies
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Reference Range:

Results are reported as positive or negative

Turnaround Time:

24Hrs

Description:

There are 4 syndromes of alpha-Thalassaemia. - ? + trait where one of the 4 globin gene loci fails to function - ?? trait where 2 loci are dysfunctional - HbH disease with 3 loci dysfunctional - HbBarts hydrops fetalii where all 4 loci are defective. These syndromes are usually due to deletions of 1 or more loci, but non deletional forms account for almost 20% of all cases. ?+ thalassaemia is particularly common in Africa, and ?? thalassaemia in South East Asia. Incubation of cells with Brilliant Cresyl Blue results in oxidation and precipitation of the HbH as multiple pale staining greenish blue almost spherical bodies of varying size which with practice and familiarity can be easily differentiated from the darker staining reticulo-filamentous material in reticulocytes.

Preparation:

Fresh whole blood is collected into bottles containing EDTA. Samples greater then 12 hours old are unsuitable for HbH body testing as Hb H is unstable and false negatives will occur.

Vessels and Containers:

1x4.5 ml EDTA blood (Purple top)

Interference:

An old sample will give a false negative result and must not be used. The stain must be made up periodically as indicated or flase negatives will result All HbH body results must be related to the overall thalassaemia screening tests e.g It is impossible to get a raised Hb A2 and a positive HbH screen If the patient is Fe deficient the test should be repeated Most positive HbH body screens are found to have low or low normal HbA2 levels

How result is reported:

All positive findings should be referred to a consultant haematologist or haematology registrar for confirmation and interpretive reporting

Transportation and Handling:

Samples shouls be received in the laboratory within 12 hours of sampling