Learning Center
Plans & pricing Sign in
Sign Out
Get this document free

PGD HLA testing


									Reference: De Wert G, Liebaers I, Van de Velde H. The Future (R) evolution of
Preimplantation Genetic Diagnosis/Human Leukocyte Antigen Testing: Ethical Reflections.
Stem Cells 2007; 25:2167-2172.

Summarized by: Aysha Mirza and Rasha R. Nayal

        Preimplantation genetic diagnosis (PGD) with HLA (human leukocyte antigen) testing
has increasingly become a topic for study as it may prove useful in identifying potentially life-
saving properties of umbilical cord blood cells. The ethical issues in conjunction with this type of
testing abound, as parents have more reason to conceive another child in order to treat diseased
offspring. The method by which parents choose to attain the ends of treating an ill child can vary
with regards to PGD/HLA testing, as will be illustrated further in this review.
        Parents have currently used PGD/HLA testing type 1 in order to verify, in utero, whether
or not a child is a compatible match for a sibling's stem cell therapy. The PGD/HLA testing in
type 1 allows for parents to make a decision to abort a non-compatible donor fetus.
        PGD/HLA type 1 testing is done to find a compatible embryo for transplantation with the
possible loss of healthy embryos similar to IVF (in vitro fertilization). This can also bring
objections against the destruction of healthy embryos.
        HLA testing causes a decrease in morbidity-related hematopoietic stem cell (HSC)
transplantation. The notion of someone conceiving a child for the purpose of treating another
child raises ethical concerns. The major issue is on behalf of the child (who is assumed to be
healthy), the mother, and the diseased sibling. Does the child, as an embryo, have any ability to
make a choice of whether or not to be a donor? Does the child even want to help his or her
sibling? If he or she is able to help his or her sibling, will the child be loved for him or herself, or
viewed solely as an HSC transplantation source? Can the family afford another child?
        The acquirement of UCB (umbilical cord blood) from a child is noninvasive. However,
clinical studies suggest that the timing at which the umbilical cord is clamped may have an
impact on both the child and the efficacy of treatment for the diseased sibling. If clamped later,
there may be additional protection for a child, such as complications associated with hemorrhage
and sepsis. Regardless of the time of clamping, the quantity of HSCs may not be sufficient to
treat the diseased sibling. If this is the case, a BM (bone marrow) transplant can be done to
obtain HSCs. Some ethicists do state that there should be an emotional bond between the
recipient and donor in order for there to be a psychological benefit to the donor. This brings up
yet another ethical boundary: could the donor child place all blame on him or herself if his or her
sibling still does not survive after the transplant?
        Another potentially murky aspect of PGD/HLA type 1 testing is that even if the mother
becomes pregnant immediately and the fetus is found to be a match, the sick child may not
survive in time for treatment. Labor may be induced early in order to help the sibling quicker
although it may seriously harm the fetus.
    PGD/HLA testing type 1 is discouraged if the child suffers from a non-hereditary condition,
if a parent is in need of HSC (parental objective reasoning is compromised) and if HLA type
matching could substantially increase the health risks of the child.
        PGD/HLA testing type 2 is the process of taking matched embryos for the potential ESC
(embryonic stem cell) therapy for a diseased sibling. Parents who feel that their family is
complete and/or may not be able to afford another child are in a better ethical position with
which to pursue PGD/HLA testing type 2. As mentioned above, a diseased sibling may die
before the 9 months necessary to bring a child to term in PGD/HLA testing type 1. PGD/HLA
testing type 2 may prove to be a better alternative.
        The use of embryos as a means to an end is prohibited in many countries. However, the
usage of IVF or IVF/PGD extra embryos is accepted. The difference between these two
situations lies within the intentions during fertilization. In the case of IVF, although each embryo
is created as a goal in itself, it is foreseen that some embryos will go to waste (In PGD/HLA
testing type 1, the amount of abandoned embryos is at best 25% less compared to IVF and testing
type 2). The fate of the discarded embryos is up to the parents. A possible solution to avoiding
creating embryos for instrumental use is the creation of a cell bank with the aforementioned
discarded embryos; however, not all patients can presently anticipate finding an exact match.
        The child-related ethical concerns are close to negligible with PGD/HLA testing type 2,
as a child would not be subjected to potential harm with stem cell collection methods as a donor.
Future implications of health complications due to HLA types would no longer be an issue as the
child would not be coming to term. PGD/HLA testing Type 2 also avoids the possibility of
psychological effects on the donor: there would no longer be a concern as to whether or not the
child was loved the same as other children and treated in the same manner, or if the child were to
take responsibility for the health or passing of his sibling.
        Although the fetalist viewpoint is normally focused on in ethical debates, the feminist
perspective should not be overlooked. The female oocyte donor has medical concerns regarding
the hormonal therapy for increased ovulation; however, PGD/HLA testing type 2 can be an
appealing alternative for women who opt not to have another pregnancy or child.
        The authors suggest that further research with respect to the safety and viability of
PGD/HLA testing type 2 is called for, as well as determining procedures with which to expand
cells ex vivo before transplantation. With regards to this review, PGD/HLA testing type 2 is seen
to be a suitable alternative to PGD/HLA testing type 1 for families that believe their families to
be complete or are unable to afford the costs of an addition to their family. i

To top