HLA Tissue Typing
HLA Tissue Typing determines whether an umbilical cord stem cell sample is compatible with another individual (e.g. a sibling) for transplantation. This test can be performed on your baby’s cord blood sample, giving you a full genetic profile of the cord blood sample you have just collected. This may be valuable information in the future for a family member.
Why we do HLA Tissue Typing?
Tissue-typing is central to all transplantation, including cord blood. Having your tissue-typed will provide a documented record of your child’s tissue-type, should the need arise for transplantation.
This is the same test (resolution) that cord blood samples are assessed for when they go into a public bank. There may be occasions where it is necessary to perform additional tests if clinically indicated. Any such tests will be determined by the physician requesting use of the sample and these can be performed prior to release.
Cells4Life use an accredited external laboratory utilising state-of-the-art, automated instrumentation.
HLA tissue-typing is a very complex scientific test. It is very laborious and is relatively expensive. Only Specially-trained scientists with the specific knowledge and background are able to perform the test. In lay terms, HLA tissue-typing simply involves taking a blood sample, at Cells4Life we will use umbilical cord blood and in some instances we will require a sample from the mother.
Technically, we perform what is called ‘intermediate-resolution HLA tissue-typing by PCR-SSOP for HLA Class I (HLA A, B and C) and Class II (HLA DR and DQ).
If a donor sample is to be used therapeutically to treat the person from whom it was taken it is known as an ‘autologous transplant’. In this case, there will be a 100% tissue match and it is very unlikely the body will reject it.
An allogeneic transplant is one where tissue is transplanted into someone different from where the tissue came e.g. from one sibling to another. Since these genetic markers (HLAs) are inherited from parents, siblings are much more likely to have similar HLAs than unrelated persons. There’s about a 25% chance that any individual’s sibling will be a suitable donor i.e. 1 in 4 chance of any one sibling being a perfect match, with increased odds in larger families. Umbilical cord blood does not need to be a perfect match to be successful.
In unrelated individuals the chances of tissue compatibility decrease considerably. Demographics play a large part in tissue matching e.g. there’s more chance of a Caucasian male in Sweden finding a match in the same population than a mixed race female finding a match in the UK.