The ethics of killing human/great-ape chimeras for their organs: a reply to Shaw et al.

Medicine, Health Care and Philosophy June 2016, Volume 19, Issue 2, pp 215–225 | Cite as The ethics of killing human/great-ape chimeras for their organs: a reply to Shaw et al. AuthorsAuthors and affiliations César Palacios-González Open Access Scientific Contribution First Online: 21 August 2015 19 Shares 1.7k Downloads 2 Citations Abstract The aim of this paper is to critically examine David Shaw, Wybo Dondorp, and Guido de Wert’s arguments in favour of the procurement of human organs from human/nonhuman-primate chimeras, specifically from great-ape/human chimeras. My main claim is that their arguments fail and are in need of substantial revision. To prove this I first introduce the topic, and then reconstruct Shaw et al.’s position and arguments. Next, I show that Shaw et al.: (1) failed to properly apply the subsidiarity and proportionality principles; (2) neglected species overlapping cases in their ethical assessment; (3) ignored the ethics literature on borderline persons; and (4) misunderstood McMahan’s two-tiered moral theory. These mistakes render an important part of their conclusions either false or problematic to the point that they would no longer endorse them. Finally I will briefly mention a possible multipolar solution to the human organ shortage problem that would reduce the need for chimeras’ organs. KeywordsChimeras Human-nonhuman chimeras Organ donation Great ape Nonhuman animals Part-human  Introduction A chimera, in biological sciences, is an organism which at cellular level is composed from at least two different sets of cells, which originated in genetically diverse organisms. Chimeras can be divided in two broad groups: primary chimeras and secondary chimeras. “Primary chimæras are formed by mixing together two early embryos, or an early embryo with isolated embryonic cell types obtained from a different embryo or cultured stem cell line. The resulting chimæra has cells of different origins, in many tissues. Secondary chimæras are formed experimentally by transplanting (or grafting) cells or tissues into animals at later stages of development, including late fetal stages, post-natal or even adult animals. The donor cells are only present in a few tissues” (The Academy of Medical Sciences 2011, 18–19). It should be emphasised that the number, origin of the cells, and the timing of the mixing could produce very different outcomes in respect of the kinds of capacities a chimera could possess. There are interspecific chimeras and intraspecific chimeras. Intraspecific chimeras are those where the sets of cells that make up the organism belong to the same biological species. For example, a human chimera can be created when two non-monozygotic early embryos fuse completely and grow into one body. The resulting entity is an organism that at cellular level is a ‘patchwork’ of both sets of human cells (Tippett 1983). Interspecific chimeras are those where the sets of cells that make up the organism belong to different biological species. For example, a goat/sheep chimera can be created by combining blastomeres from four-cell goat embryos with blastomeres from four-cell sheep embryos, the resulting entity is an organism that at cellular level is a ‘patchwork’ of goat cells and sheep cells (Fehilly et al. 1984). Intraspecific nonhuman/nonhuman chimeras and interspecific human/nonhuman chimeras (henceforth, HNH-chimeras) are used both in biological research that aims at improving, or maintaining, human health and in research that aims at advancing our understanding of various biological mechanisms and processes. For example, mouse-human chimeras have been used in the research of human haematopoiesis; development and function of the immune system; infectious diseases; autoimmunity; cancer; human cell development, maturation and migration; and regenerative medicine (Shultz et al. 2007; Rashid et al. 2014; Sun et al. 2007; Tam and Rossant 2003; Lapidot 2001). HNH-chimeras have also been proposed as possible tools for creating vaccines against deadly diseases such as malaria, dengue, Hepatitis B, HIV and Hepatitis C (Davis and Stanley 2003; Sacci Jr. et al. 2006; Legrand et al. 2009; Bhan et al. 2010). In recent work David Shaw, Wybo Dondorp, Niels Geijsen, and Guido de Wert have examined, from an ethical and legal position, the procurement, for human transplantation purposes, of human organs created within HNH-chimeras. In one paper Shaw examined the legal status of creating HNH-chimeras for obtaining human organs under Swiss legislation; in another, Shaw, Dondorp, Geijsen, and de Wert assessed the ethical issues surrounding the procurement of human organs from human/pig chimeras; and in a final paper Shaw, Dondorp, and de Wert assessed the ethical issues surrounding the procurement of human organs obtained from human/nonhuman-primate chimeras (Shaw 2014; Shaw et al. 2014a, b). This philosophical research stems, in part, from recent advances in induced pluripotent stem cell (iPSC) research, and the ad hoc creation of solid organs within intraspecific and interspecific chimeras (Kobayashi et al. 2010; Isotani et al. 2011; Usui et al. 2012; Matsunari et al. 2013; Kobayashi et al. 2014; Rashid et al. 2014). The aim of this paper is to critically examine the arguments that have been advanced by David Shaw, Wybo Dondorp, and Guido de Wert in favour of the procurement of human organs obtained from human/nonhuman-primate chimeras, specifically from great-ape/human chimeras. There are two important reasons for examining such arguments. First, for those that hold that there are degrees of moral status, based upon cognitive capacities,1 the ethics of using great apes for medical research that aims at benefiting humans is a topic that merits special attention. Second, the ethics of using chimeras for their human organs is a topic that warrants notice in the medical ethics literature at this point given recent developments in biological sciences. For example, in a recent paper Madhusudana Girija Sanal has sketched a road map for how to create a transplantable human liver within a chimpanzee/human chimera (Sanal 2011). My claim is that the arguments that these authors have advanced fail to support their conclusions, and thus they are in need of substantial revision. In order to prove this first I present a detailed reconstruction of Shaw et al.’s arguments. Secondly, and relying on a cognitive capacities account of moral status, I show that Shaw et al. committed major errors: (1) not properly applying the subsidiarity and proportionality principles; (2) not including species overlapping cases in their ethical assessment; (3) ignoring the ethics literature on borderline persons; and (4) misunderstanding McMahan’s two-tiered moral theory. Finally I will mention a possible multipolar solution to the human organ shortage problem that would reduce the need for HNH-chimeras’ organs. Human organs, nonhuman animal research, and moral st (...truncated)