The dangers of xenotransplantation by Ally Leaver from Surbiton High

Most animal organs in human transplants come from pigs for a number of reasons including: their organs are a similar size to ours, their organs are anatomically similar to those of humans, and they would be readily available when we need them. But why don’t we use other animals that are closer to humans such as chimpanzees? Imagine we used chimpanzee organs instead. Think about how that would make you feel. You feel a bit more uncomfortable using these organs rather than pigs, right? We feel this instinctively because chimpanzees are closely related to us but what we maybe don’t realise is that we are now placing more importance on one species over another purely because we see ourselves in these animals. If we apply the slippery slope argument to this situation, where does the line cross of an animal being too close to human? What does this even mean? And how do we measure an animal’s level of humanity? Only using pigs’ organs reveals hypocrisy and also human’s desire to avoid facing the serious ethical and biological concerns as it creates a divide between humans and the animal we are exploiting. 

As well as raising lots of ethical concerns, there are also biological and medical factors that need to be considered. A big danger of using another animal, such as pigs, for a human transplant is the risk of the patient’s immune system rejecting the organ because it is recognised as a foreign tissue. This rejection occurs because of proteins on the surface of cells called antigens which are recognised by the body’s immune system as foreign and then attacked, leading to a transplant rejection. In xenotransplantation hyperactive rejection can occur where the immune system sets out to destroy the transplanted organ in a matter of minutes. To avoid this, the pig’s embryo is injected with human genetic material and the patient also uses immune-system-suppressing drugs. This sounds perfect right? But these immunosuppressant drugs also come with their own serious risks such as infection because the drugs weaken your immune system which means your body is less resistant to infection and any infection you do get will be harder to treat. In addition, due to genetic engineering needing to take place it can take over 2 years from cell work to pregnancy with the modified embryo. Not only is this a lengthy process, but an expensive one too which we have no idea if the NHS can afford, especially in regards to the strain the NHS has been under for the last 2 years. Also, according to NCBI, only 50% of patients with a xenotransplant survive for 3 months and these months are spent in hospital, in pain, and in suffering. You’ve all heard of the man who received the first pig heart transplant in the US. This was an amazing breakthrough in science. But tragically, on the 8th of March he died after surviving only 2 months.  This poses the question, is this really that beneficial to society when we take into consideration all of the disadvantages and concerns?

As well as this there is also the fear of transferring potentially fatal viruses such as porcine endogenous retroviruses and viral zoonosis which can be transferred from pigs to people through transplanted organs. But surely if the pigs are genetically modified it will decrease the risk of these infections, right? Wrong. The risk of viral zoonosis remains and is actually increased in pigs that are genetically engineered. This could introduce new infections to the human community that were not previously endemic in human populations and I think we can all agree that the last thing we need is another pandemic. We’ve all heard of HIV and we all know how dangerous it is. Well, what if I told you that porcine endogenous retroviruses are actually in the same class as HIV. These retroviruses can break out of the pig’s DNA to become independent infectious pathogens which your body does not know how to react to.