Context:
Richard Slayman, the first human recipient of a genetically modified pig kidney transplant, passed away around two months after the surgery.
About Xeno transplantation
It is a medical procedure that involves transplanting living organs, tissues, or cells from one species to another. In simpler terms, it’s the process of using animal organs for human transplants.
Xeno transplantation Process:
- Surgical procedure similar to regular organ transplants.
- Genetic modifications of animal organs to prevent rejection by the human body.
- CRISPR-Cas9 employed for genomic edits, removing pig genes producing antibodies and adding human genes for compatibility.
- Constant monitoring required post-operation to assess the body’s response to the transplanted organ.
Why Xenotransplantation?
- Organ Shortage: The demand for organs for transplants far exceeds the availability of human donors. Xenotransplantation offers a potential solution to this critical shortage.
- A 2024 article in Nature notes: “In the United States alone, there are nearly 90,000 people waiting for a kidney transplant, and more than 3,000 people die every year while still waiting.” Similar anatomical and physiological parameters to humans.
- Universal Donors: Animal organs, especially from pigs, could potentially act as universal donors, overcoming issues like blood type incompatibility that can limit human-to-human transplants.
- Significant potential for treating various medical conditions, including neurodegenerative disorders, diabetes, and organ failure.
Why Pigs?
- Similarities: Pig heart valves have been used for replacing damaged valves in humans for over 50 years now. Pig organs have a similar size and anatomy to human organs, making them potentially compatible for transplantation.
- Rapid Growth: Pigs can be bred relatively quickly, allowing for a faster and more reliable source of organs compared to other animals. Pigs bred in farms are cost-effective.
- Genetic Engineering: Scientists are working on genetically modifying pigs to further reduce the risk of organ rejection by the human body. This involves removing genes that trigger immune response and adding human genes to promote organ acceptance.
Challenges of Xenotransplantation:
- Immune Rejection: The human body’s immune system may recognize the animal organ as foreign and reject it. This is a major hurdle that researchers are trying to overcome through genetic modification and immunosuppressive drugs.
- Retrovirus Transmission: Risk of cross-species infection by latent retroviruses, potentially leading to disease years after transplantation.
- Ethical Concerns: The use of animals for organ transplants raises ethical questions about animal welfare and the potential for unintended consequences.
Recent Cases:
- January 2022, First xenotransplantation of a genetically modified pig heart, resulting in the patient’s death after two months due to a range of factors, including being tainted with a latent virus in the pig heart, which may have contributed to the dysfunction of the transplant.
- Slayman’s case: No indication that his death was directly related to the transplant.