Type-one diabetes is a severe disease that currently affects around 34. 7million people worldwide. It is an auto-immune disease where the body’s immune system attacks the beta cells in the pancreas, these cells are the ones who produce the hormone; insulin. Insulin controls the special carrier proteins on a cells membrane and controls the amount of glucose that passes into the cell; this is responsible for your blood sugar level. Type-one diabetes is “characterized by deficient insulin production and requires daily administration of insulin” by the World Health Organization (WHO).
Because of the absence of these cells in type-one diabetic patients hyperglycaemia or high blood sugar levels are caused. Hyperglycaemia and “yo-yoing” blood sugar levels cause problems with eye-sight, kidney disease, and damage to the nervous system and heart problems. There is currently no cure or treatment for diabetes, only management of insulin and blood sugar levels through healthy diet and daily insulin injections. What Is Xenotransplantation?
Xenotransplantation is defined as “the transplantation, implantation or infusion into a human recipient of either (a) live cells, tissues, or organs from a non-human animal source or (b) human body fluids, cells, tissues, or organs that have had ex vivo contacts with live non-human animal cells, tissues, or organs” for instance the transfer of pig islet cells into a human patient. Xenotransplantation was first tried in the early 1900’s but for due to rejection was discarded. It then re-emerged in the 1960’s when advances in immunology enlightened scientists to why the original transplants were rejected.
Xenotransplantation has become considered as a better and more sustainable option for the treatment of organ failure and life-threatening diseases as the critical shortage of donated organs for allotransplantation continues to plague the medical sector. Last year only one third of people on the waiting list received organ transplantations. This year there are currently nearly 120,000 people awaiting organ transplants in the United States Of America alone, including 1,760 pediatric patients. Xenotransplantation carries many biological risks; because the transplantation is foreign matter to the body the immune system will reject the transplant.
There are two types of rejection associated with xenotransplantation; hyperacute rejection and acute rejection. Hyperacute rejection occurs within hours of the transplantation taking place and occurs mostly in transplants with animals that are incongruent to humans/ human DNA, for example pigs. This is caused by a sugary enzyme which is present on the surface of the animal’s organs; this causes clotting and occurs within 20 minutes of the operation. Recently genetic engineering has allowed scientists to “knock out” the gene that causes the enzyme and prevent hyperacute rejection.
Acute rejection of transplants occurs with transplants from animals that are congruent with humans, for example; monkeys. Acute rejection can be managed with immunosuppressant drugs. Though the use of pigs’ heart valves has become common practice in the medical world xenotransplantation is still in its early stages and has yet to become commercialised. Most transplants between animals and humans are still in the research and clinical trial stages, but xenotransplantation seems to be a promising and sustainable alternative to allotransplantation, and promising cure for organ failure and fatal diseases.
Pig Islet Cell Xenotransplantation Procedure Developed By The LCT Company? The New Zealand based Living Cell Technologies (LCT) Company has developed a porcine tissue procedure, which removes islet cells from pigs, encapsulates them in an algae based coating and implants them into patients suffering from Type-One Diabetes. This treatment is in the clinical trial stage and has already completed phase one of human trials of the diabetes treatment called DIABECELL.
Diabecell is a porcine tissue procedure it starts by extracting the islet cells from a neo-natal pigs pancreas, this is usually is the demise of the pig. These islet cells are then isolated and put inside an alginate micro-capsule (see figure 1). The encapsulated coating and cell are about the size of a grain of sand. These encapsulated cells are then injected into the patient’s abdomen. The pig islet cells are able to function well within the abdomen cavity; they produce insulin and control the patients’ blood sugar levels.
The alginate micro-capsule lets nutrients to enter the capsule to keep the cell healthy, and lets the produced insulin out of the cell but does not let the immune systems antibodies to reach the cell, to attack it. Isolating high quality islet cells from neonatal pigs is the first step in the Diabecell treatment. The LCT Company is lucky in this case as they have exclusive rights to a herd of Auckland Island pigs. The Auckland Island pigs were originally placed on the Auckland islands between New Zealand and Antarctica, in the 1800’s by sailors who released them as a food source for shipwreck survivors.
Due to their isolation over the past 200years the pigs are disease free, they are considered the only herd of pigs that have not contracted the PERV virus, a retrovirus endogenous to pigs. Because the pigs are disease and virus free they are considered acceptable donors for xenotransplantation procedures. This is because one of the major biological concerns with xenotransplantation is the possibility a porcine endogenous virus be contracted by the patient, and pass it on to other humans cause an endemic.
Because the Auckland island pigs are disease and virus free there is no chance of a cross species contamination. The herd of Auckland Island pigs are kept in a high class facility that is virus and pathogen free. The pigs are kept under a basic quarantine and measures have been taken to keep them disease free. These measures include: * No pigs allowed within 10km of the facility. * No pigs previously kept on property. * HEPA filtered air supply. * Water filtered and UV treated. * Goods to enter are sterilised. * All staff fully trained in biosecurity measures. No staff allowed to enter if had contact with any other pigs or rodents. * No visitors. The second step in the Diabecell procedure is the encapsulation of the islet cell. The alginate micro capsule is about the size of a grain of sand and protects the living islet cell from the patient’s immune system. The coating is a semi-permeable membrane that allows nutrients such as glucose into the cell; this is to keep the cell healthy and to turn the nutrients into insulin. Once insulin is produced is allowed to exit the cell, and enter the blood stream.
The anti-bodies in the patient’s immune system cannot pass through the coating. This is so the immune system does not recognise the cell as foreign and begin to attack and destroy the cell, the same way they deal with viruses. Because of the encapsulation immunosuppressant drugs are not necessary after the procedure. The encapsulated islets cells are then injected into the patient’s abdomen, the dosage depend on the weight of the patient. It is unclear at this stage of the clinical trials how long the cells will continue to produce insulin.
The trial has demonstrated so far that Diabecell is a safe and effective treatment for type-one diabetes. Biological Issues Concerning The Procedure? The main biological concern with the xenotransplantation of porcine islet cells into diabetic patients is the rejection of the cells and the use of immunosuppressant drugs. As the cells are coated in an alginate micro-capsule the immune system will not be able to recognise or attack the cell. The use of immunosuppressant drugs is not necessary as the cell is encapsulated.
Ethical Issues Concerning The Procedure? There are some ethical and cultural implications to the procedure that need to be overcome before the treatment is commercialised. Ethical: There are groups of people who believe that the raising of pigs for xenotransplantation is inhumane “others have strong moral convictions against using animals for any purpose, no matter how humans might benefit”, though “many people believe it would be okay to use animals if the benefits to humans are important and if the animals are properly cared for”.
It is now commonly accepted within society and the wider scientific community that because the pigs would have great value in medical and economic terms, they would likely receive a high level of care, with their health and welfare being of the upmost importance. Some people believe that one benefit to use pigs for xenotransplantation would be the continuous medical care they would receive and the improved conditions they would be kept in. The pigs would be kept in small herd sizes and contained in high quality facilities that must follow a high standard of welfare.
Spiritual: There is a group of people who think xenotransplantation is a lack in morality for religious reasons. Though many religious groups have accepted that the benefits of xenotransplantation outweigh the moral convictions of the process, some religious groups are against xenotransplantation. Judaism clearly states that pork and any human use of pigs is outlawed. Buddhism and Hinduism believe that one of the most important teachings is to protect animals and so are against the use of animals to benefit xenotransplantation.
Social: Many patients may not be able to cope with the psychological implications of xenotransplantation. Some patients are not able to cope with the idea of not being complete as a person, and after transplantation seem to lose their identity. Also with the possible complications of xenotransplantation the patient may be required to comply with lifelong check-ups. Personal Opinion On The Procedure And Proposed Courses Of Action? Personally I am for the Diabecell treatment for type-one diabetes.
In my perspective the LCT Company has developed a life-changing treatment for a previously incurable disease, and this should be available for all patients suffering from diabetes. I think that the treatment is an ethical procedure and that the guidelines in place from the governing authorities ensure that the treatment of the parties involved continues to be ethical. The herd of Auckland Island pigs who donate the cells are treated to high welfare standards, well above those of pigs farmed for pork and other meat products.
I believe the value of a pigs life does not measure to the benefits of the treatment for the patients involved. Though I am not from a religious background I understand that some religions have spiritual issues with the use of pig cells for the treatment of diabetes, as the patient will have to give full and informed consent for the procedure to take place I believe that those with religious issues with the treatment can opt out. The islet cell xenotransplantation improves the quality of life for patients for at least 10. 9 years. My proposed course of action is to raise public awareness using the available media outlets.
This will hopefully make the public informed and engaged in the ethical process of the treatment. Hopefully this will raise public discussion on how society feels about the treatment and the ethical implications of the procedure. I would advise a public relations committee to be formed to answer the public’s queries and concerns. Validity Of Resources? I have used resources from many sources with many different viewpoints. I used many internet resources because they are up to date and show varying perceptions I processed websites which showed differing ideas about xenotransplantation.
I only used websites that could not be changed or altered by any user as people could change information to support their ideas, this information could be false or heavily biased. This excluded sites such as Wikipedia. I mostly used sites that were original sources of information, for example the LCT Company’s press releases, surgical encyclopaedia, media releases and ethical committee reports. I heavily relied on information from review committees and media release as this information is not biased and shows an overview of the treatment in a broader context.