World-first xenotransplant

Surgeons in the U.S. have transplanted the heart of a genetically modified pig into a human, marking a step in the decades-long quest in using animal organs for life-saving transplants


1. GalSafe pigs: Sugar group called alpha-gal occurs on pigs’ cell surfaces. Alpha-gal enzyme triggers rejection by human immune system

Alpha-gal 
Nucleus
Pig DNA 
Pig cell

DNA
Porcine chromosome
Gene
Pig egg

2. Alpha-gal: Gene blocked. Growth gene inactivated to prevent heart from continuing to grow after implantation

3. Human genes: Inserted into pig DNA to prevent blood coagulating in heart and make organ more tolerable to immune system. DNA used to breed herd of GalSafe donor pigs


1954: First successful human to human transplant – kidney

1960: First immunosuppressive drugs identified

1963: Baboon and chimpanzee to human kidney transplants.
One patient survives nine months

1964-74: Failed attempts at chimpanzee heart, liver transplants

1978: Pig skin successfully used to treat burns patients

1984: Baboon heart transplant in baby. Infant survives 20 days

1992-93: Baboon-human liver transplants

1995: Transgenic pigs prevent transplant rejection

2007-17: Pig cell transplants to treat Type 1 diabetes and Parkinson’s disease

Lung
Heart
Liver
Kidney


Sources: Smithsonian, U.S. Food and Drug Administration, UPI
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