Preimplantation HLA typing: having children to save our loved ones

Conception of Saviour Siblings: Ethical Perceptions of Selected Stakeholders in Malaysia

The conception of saviour siblings using preimplantation genetic diagnosis coupled with human leukocyte antigen (HLA) typing or HLA typing alone is controversial and receives a wide divergence of legal responses among countries around the world. The resulting child conceived through this procedure is dubbed a 'saviour sibling' as the child can potentially act as a compatible donor for an elder ailing sibling who needs a haematopoietic stem cell transplantation. At present, the acceptability of this procedure in Malaysia is ambiguous as there is no specific statute governing assisted reproductive technology, and the guideline issued by the Malaysian Medical Council does not expressly address this issue. The ethical arguments relating to the conception of saviour siblings in the current literature are mainly thought to reflect a liberal viewpoint which is predominantly Western in nature. This paper seeks to explore the perception of selected key stakeholders on the acceptability of and ethical concerns related to this procedure in the Malaysian context. The findings indicate that stakeholders generally support the conception of saviour siblings and some of their concerns echo the Western viewpoint. Interestingly, many were highly anxious about its economic implication, which is rarely discussed in the current literature on saviour siblings.

HLA Matching in Pediatric Stem Cell Transplantation

For several malignant and nonmalignant disorders such as leukemias, lymphomas, or inborn errors of hematopoiesis, stem cell transplantation is the only curative option. Depending on the underlying cause of the disease, the conditioning regimens, source of the stem cells, and graft composition may vary. Possible stem cell donors are selected from databases considering existing major histocompatibility genes of the donor and the recipient. This is currently performed by matching human leukocyte antigen (HLA)-A, -B, and -C for class I, as well as HLA-DRB1 and -DQB1 for class II. Stem cell transplantation for nonmalignant disorders is a specialty of pediatrics. While algorithms for donor selection in these cases are generally similar, the objective of optimizing a possible graft-versus-leukemia effect is less important. In this article, we aim to provide an overview on the current methods for HLA typing and the algorithms for HLA matching. We also address ethical aspects regarding children and minors as stem cell donors.

The clinical utility of PGD with HLA matching: a collaborative multi-centre ESHRE study

STUDY QUESTION

Has PGD-HLA been successful relative to diagnostic and clinical efficacy?

SUMMARY ANSWER

The diagnostic efficacy of PGD-HLA protocols was found lower in this study in comparison to published PGD-HLA protocols and to that reported for general PGD by ESHRE (78.5 vs 94.1% and vs 92.6%, respectively), while the clinical efficacy has proven very difficult to assess due to inadequate follow-up of both the ART/PGD and HSCT procedure outcomes.

WHAT IS KNOWN ALREADY

The first clinical cases for PGD-HLA were reported in 2001. It is now a well-established procedure, with an increasing number of cycles performed every year. However, PGD-HLA is still offered by relatively few PGD centres, the currently available data is fragmented and most reports on PGD-HLA applications are limited in number and scope. Published systematic details on methodology, diagnostic results, overall ART success and haematopoietic stem cell transplantation (HSCT) outcomes are limited, precluding an evaluation of the true clinical utility of PGD-HLA cycles.

STUDY DESIGN, SIZE, DURATION

This retrospective multi-centre cohort study aimed to investigate the diagnostic and clinical efficacy of the PGD-HLA procedure and the aspects of PGD-HLA cycles influencing positive outcomes: birth of genetically suitable donor-baby (or babies) and HSCT. In April 2014, 32 PGD centres (Consortium members and non-members) with published/known PGD-HLA activity were invited to participate. Between February and September 2015, 14 centres submitted their data, through a custom-designed secure database, with unique login access for each centre. Data parameters covered all aspects of PGD-HLA cycles (ART, embryology and genetic diagnosis), donor-babies born and HSCT.

PARTICIPANTS/MATERIALS, SETTING, METHODS

From 716 cycles submitted by 14 centres (performed between August 2001 and September 2015), the quality evaluation excluded 12 cycles, leaving 704, from 364 couples. The online database, based on REDCap, a free, secure, web-based data-capture application, was customized by Centre for Clinical Epidemiology and Outcomes Research (CLEO), Athens. Continuous variables are presented using mean, standard deviation, median and interquartile range, and categorical variables are presented as absolute and relative frequencies.

MAIN RESULTS AND THE ROLE OF CHANCE

The data included 704 HLA-PGD cycles. Mean maternal age was 33.5 years. Most couples (81.3%) requested HLA-typing with concurrent exclusion of a single monogenic disease (58.6% for beta-thalassaemia). In 92.5% couples, both partners were fertile, with an average 1.93 HLA-PGD cycles/couple. Overall, 9751 oocytes were retrieved (13.9/cycle) and 5532 embryos were analysed (7.9/cycle). Most cycles involved fresh oocytes (94.9%) and Day 3 embryo biopsy (85.3%). In 97.5% of cycles, the genotyping method involved PCR only. Of 4343 embryos diagnosed (78.5% of analysed embryos), 677 were genetically suitable (15.4% of those analysed for HLA alone, 11.6% of those analysed for HLA with exclusion of monogenic disease). Of the 364 couples, 56.6% achieved an embryo transfer (ET) and 598 embryos were transferred in 382 cycles, leading to 164 HCG-positive pregnancies (pregnancy rate/ET 41.3%, pregnancy rate/initiated cycle 23.3%) and 136 babies born (live birth rate/ET 34.3%, live birth rate/initiated cycle 19.3%) to 113 couples. Data analysis identified the following limitations to the overall success of the HLA-PGD procedure: the age of the mother undergoing the treatment cycle, the number of oocytes collected per cycle and genetic chance. HSCT was reported for 57 cases, of which 64.9% involved combined umbilical cord-blood and bone marrow transplantation from the HLA-identical sibling donor; 77.3% of transplants reported no complications.

LIMITATIONS REASONS FOR CAUTION

The findings of the study may be limited as not all PGD centres with PGD-HLA experience participated. Reporting bias on completion of the online database may be another potential limitation. Furthermore, the study is based on retrospective data collection from centres with variable practices and strategies for ART, embryology and genetic diagnosis.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first multi-centre study evaluating the clinical utility of PGD-HLA, indicating variations in practice and outcomes throughout 15 years and between centres. The study highlights parameters important for positive outcomes and provides important information for both scientists and couples interested in initiating a cycle. Above all, the study underlines the need for better collaboration between all specialists involved in the ART-PGD/HLA procedure, as well as the need for comprehensive and prospective long-term data collection, and encourages all specialists to aim to properly evaluate and follow-up all procedures, with the ultimate aim to promote best practice and encourage patient informed decision making.

STUDY FUNDING/COMPETING INTEREST(S)

The study wishes to acknowledge ESHRE for funding the customization of the REDCap database. There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Born to donate: proposals for "savior sibling" regulation in Latin America

A Savior Sibling is a child who is born to provide an organ, bone marrow or cell transplant, to a sibling that is affected with a fatal disease. There are created with the in vitro fertilization and pre-implantation genetic diagnosis and, in the process, the ethical standards for organ donation of children become less demanding. Therefore, we propose that the authorization of the technique considers, unavoidably, the opinion of an impartial third party that can guarantee the welfare of the child. We develop a critical analysis of the laws that regulate the creation of babies to serve as organ donors. We evaluate under what circumstances the organizations that play a part in the decisions, fulfill the ethical standards to allow the organ donation of children.

Comparing Non-Medical Sex Selection and Saviour Sibling Selection in the Case of JS and LS v Patient Review Panel: Beyond the Welfare of the Child?

The national ethical guidelines relevant to assisted reproductive technology (ART) have recently been reviewed by the National Health and Medical Research Council (NHMRC). The review process paid particular attention to the issue of non-medical sex selection, although ultimately, the updated ethical guidelines maintain the pre-consultation position of a prohibition on non-medical sex selection. Whilst this recent review process provided a public forum for debate and discussion of this ethically contentious issue, the Victorian case of JS and LS v Patient Review Panel (Health and Privacy) [2011] VCAT 856 provides a rare instance where the prohibition on non-medical sex selection has been explored by a court or tribunal in Australia. This paper analyses the reasoning in that decision, focusing specifically on how the Victorian Civil and Administrative Tribunal applied the statutory framework relevant to ART and its comparison to other uses of embryo selection technologies. The Tribunal relied heavily upon the welfare-of-the-child principle under the Assisted Reproductive Treatment Act 2008 (Vic). The Tribunal also compared non-medical sex selection with saviour sibling selection (that is, where a child is purposely conceived as a matched tissue donor for an existing child of the family). Our analysis leads us to conclude that the Tribunal's reasoning fails to adequately justify the denial of the applicants' request to utilize ART services to select the sex of their prospective child.

First experience of hematopoietic stem cell transplantation treatment of Shwachman-Diamond syndrome using unaffected HLA-matched sibling donor produced through preimplantation HLA typing

The only proven cure for Shwachman-Diamond syndrome (SDS) bone marrow failure is allogeneic hematopoietic stem cell transplantation (HSCT). However HSCT with donors other than HLA-identical siblings is associated with high mortality and unfavorable prognosis. This paper presents the first experience of HSCT treatment of SDS using an unaffected HLA-identical sibling produced through preimplantation genetic diagnosis (PGD). The patient was a 6-year-old blood transfusion-dependent SDS baby girl with secondary myelodysplastic syndrome, for whom no HLA-identical donor was available. As a result of PGD, two unaffected HLA matched embryos were identified; one of them was randomly selected for transfer, resulting in a clinical pregnancy and birth of an apparently healthy child. The patient underwent allogeneic transplantation of cord blood hematopoietic stem cells, together with bone marrow from this sibling, resulting in complete hemopoietic recovery. The patient was no longer transfusion-dependent and had normal blood values 160 days after transplantation.

Preimplantation genetic diagnosis for monogenic diseases: overview and emerging issues

Preimplantation genetic diagnosis (PGD) is an established reproductive option for couples at risk of conceiving a pregnancy affected with a known genetic disease, who wish to avoid an (additional) affected child, termination of pregnancy or recurrent miscarriages. Early technologies concentrated on different approaches to direct mutation testing for monogenic diseases using single cell PCR protocols, or sex selection by fluorescent in situ hybridization for X-linked monogenic disease. Development of multiplex fluorescent PCR allowed simultaneously testing of linked markers alongside the mutation test, increasing the accuracy by controlling for contamination and identifying allele drop-out. The advent of highly effective whole genome amplification methods has opened the way for new technologies such as preimplantation genetic haplotyping and microarrays, thus increasing the number of genetic defects that can be detected in preimplantation embryos; the number of cases carried out and the new indications tested increases each year. Different countries have taken very different approaches to legislating and regulating PGD, giving rise to the phenomenon of reproductive tourism. PGD is now being performed for scenarios previously not undertaken using prenatal diagnosis, some of which raise significant ethical concerns. While PGD has benefited many couples aiming to have healthy children, ethical concerns remain over inappropriate use of this technology.

Singling out genetic disorders and disease

Preimplantation genetic diagnosis (PGD) involves testing of single cells biopsied from oocytes and/or embryos generated in vitro. As only embryos unaffected for a given genetic condition are transferred to the uterus, it avoids prenatal diagnosis and termination of pregnancy. Follow-up data from PGD pregnancies, deliveries and children show an acceptable live birth rate and, so far, no detrimental effects of the procedure have been observed. Of course, the long-term health outcome is currently unknown. PGD was first performed in 1990 and remained an experimental procedure for a number of years. Now, two decades later, it is regarded as an established alternative to prenatal diagnosis: its use has expanded, the range of applications has broadened, and continuous technical progress in single-cell testing has led to high levels of efficiency and accuracy. The current gold standard methods (single-cell multiplex-PCR for monogenic diseases and interphase fluorescence in situ hybridization for chromosomal aberrations) are being replaced by single-cell whole genome amplification and array technology. These generalized methods substantially reduce the pre-PGD workload and allow more automated genome-wide analysis. The implementation of laboratory accreditation schemes brings the field at the same level of routine diagnostics. This article reviews the state of the art and considers indications, accuracy and current technical changes in the field of PGD.

Saviour embryos? Preimplantation genetic diagnosis as a therapeutic technology

The creation of 'saviour siblings' is one of the most controversial uses of preimplantation genetic diagnosis (PGD). This paper outlines and invites ethical discussion of an extension of this technology, namely, the creation of 'saviour embryos' to serve as a source of stem cells to be used in potentially life-saving therapy for an existing child. A number of analogies between this hypothetical use of PGD and existing uses of IVF are offered and, in addition, between saviour embryos and proposed therapeutic applications of stem cell technology. The ethical significance of a number of disanalogies between these cases are explored and investigated. While the creation of saviour embryos would involve a significant shift in the rationale for IVF and PGD, it is suggested here that the urgent need of an existing individual should be prioritised over any obligations that might exist in relation to the creation or destruction of human embryos.

American Academy of Pediatrics. Committee on Bioethics. Children as hematopoietic stem cell donors

In the past half-century, hematopoietic stem cell transplantation has become standard treatment for a variety of diseases in children and adults, including selected hematologic malignancies, immunodeficiencies, hemoglobinopathies, bone marrow failure syndromes, and congenital metabolic disorders. There are 3 sources of allogeneic hematopoietic stem cells: bone marrow, peripheral blood, and umbilical cord blood; each has its own benefits and risks. Children often serve as hematopoietic stem cell donors, most commonly for their siblings. HLA-matched biological siblings are generally preferred as donors because of reduced risks of transplant-related complications as compared with unrelated donors. This statement includes a discussion of the ethical considerations regarding minors serving as stem cell donors, using the traditional benefit/burden calculation from the perspectives of both the donor and the recipient. The statement also includes an examination of the circumstances under which a minor may ethically participate as a hematopoietic stem cell donor, how the risks can be minimized, what the informed-consent process should entail, the role for a donor advocate (or some similar mechanism), and other ethical concerns. The American Academy of Pediatrics holds that minors can ethically serve as stem cell donors when specific criteria are fulfilled.

Three Bioethical Debates in Sweden

Three of the bioethical issues recently discussed in Sweden appear to be particularly interesting also to an international audience. A new law allowing restrictive use of preimplantation genetic diagnosis (PGD)/human leukocyte antigen (HLA) (“savior siblings”) has been implemented, a new recommendation for the cessation of life-sustaining treatment has been issued, and the scope of individual responsibility for medical mistakes has been rather thoroughly discussed.

Preimplantation genetic diagnosis: an overview of socio-ethical and legal considerations

Preimplantation genetic diagnosis (PGD) permits the selection of embryos of a particular genotype prior to implantation. As a reproductive technology involving embryo selection, PGD has become associated with considerable controversy. This review examines some of the ethical, legal, and social issues raised by PGD. Relevant ethical considerations include the status of the embryo and the interests and duties of the parents. On a social policy level, considerations of access as well as the impact of this technology on families, women, and physician's duties also warrant consideration. An analysis of these issues in the context of using PGD for selecting embryos unaffected by a serious disorder and for sex selection is presented. We also present a brief survey of PGD-related regulatory schemes in several countries, including the United Kingdom and the United States.

PGD-derived human embryonic stem cell lines as a powerful tool for the study of human genetic disorders

Human embryonic stem (ES) cells are derived from the inner cell mass (ICM) of blastocyst embryos. They are established from spare embryos that have been obtained by in vitro fertilization (IVF) and donated for research purposes. The ICM-derived cell lines have two unique properties, they can be propagated indefinitely in culture and have the potential to develop into practically any cell type in vitro and in vivo. Human embryonic stem (hES) cells carrying specific mutations can be used as a valuable tool for studying genetic disorders in human. One favorable approach to obtain such mutant ES cell lines is their derivation from affected preimplantation genetic diagnosed (PGD) embryos. This review focuses on the importance of deriving human ES cell lines from genetically abnormal embryos, especially in cases where no good cellular and/or animal models exist.

Complexities in reproductive choice: medical professionals' attitudes to and experiences of pre-implantation genetic diagnosis

Studies have been made on attitudes to and experiences of women and men who have undergone pre-implantation genetic diagnosis (PGD), or who are regarded as potential users of this diagnostic method. Few studies have been conducted regarding the attitudes to and experiences of medical professionals as regards PGD. This paper reports on findings from such a qualitative study in which 18 semi-structured interviews were performed with geneticists and gynaecologists in Italy, Sweden and the UK. Interviewees emphasized, among other things, the importance of choice provision. Interviewees also told stories that indicated the many ways through which choice was feared to be hampered - or was hampered. A similar emphasis on the importance of PGD as one more alternative to choose between, for 'high-risk' couples, is not found in studies on the experiences, attitudes and views of potential, or actual, users of PGD.

On new reproductive technologies and family ethics: pre-implantation genetic diagnosis for sibling donor in Israel and Germany

This paper discusses the policy debate and ethical discussion surrounding pre-implantation genetic diagnosis (PGD) for sibling donor (SD) in Germany and Israel. Based on an analysis of the regulations and ethical discourse concerning a unique form of new reproductive technology (NRT)--PGD for SD--we complement the scholarly discussion of NRTs in these countries, by pointing to an explanatory factor that has been so far neglected, namely the hegemonic notions regarding the ideal relationship between the generations, and the mutual obligations between different family members in Germany and Israel. We argue the fact that PGD (in general) and PGD for SD (in particular) have been banned in Germany, but were endorsed without hesitation in Israel, has to do with different perceptions of family ethics within the two societies. Furthermore, we argue that this factor contributes significantly to the more general understanding of German and Israeli policies regarding NRTs.