Question: Hi! My dad had a kidney transplant in 2015 and I have always been interested in finding out more about how the surgery worked and the after process, im am aware that some people have to go through Therapeutic Cloning after surgery because the stem cells can sometimes recognise them an organism isn't theirs and has come from somewhere different. When reading about what you study I was intrigued about the 'invisible cloak' maybe if you could expand of what that will do and how it will help the future patients undergo surgery so there's a higher chance of success?

Katrina Wesencraft answered on 28 Apr 2020: last edited 28 Apr 2020 7:38 pm

Hi, thanks for your message – this is a really interesting question!

First of all, I research one type of transplant called a pancreatic islet transplant. It’s an experimental treatment for people with severe type 1 diabetes. In this transplant, you only want to replace the cells that stop working in diabetes (which are only about 1% of the pancreas!). To get these cells out, the donor pancreas gets mashed up with enzymes. The useful cells, or islets, that make insulin are transplanted through a tube into the patient’s liver – so quite different to a kidney transplant!
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One thing that’s similar in both pancreatic islet transplant and kidney transplants is that the faulty organs aren’t usually removed. There’s space in the bottom of the abdomen (the space below your stomach) for an extra kidney. Because the kidney filters blood and produces urine, the surgeon needs to sew the new donor kidney’s blood vessels up to the blood vessels of the patient. They’ll also join the donor kidney’s ureter to the patient’s to carry the urine to the bladder.
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A kidney from an organ donor will be matched up by size, blood type and tissue type to someone who is on the transplant waiting list. But you’ll never get a perfect match – there are a lot of different tissue types.
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For tissue matching, they do a DNA test of the patient and donor to find out the type of molecules (called antigens) that are present on their cells. One reason it’s so difficult to match is that this part of our DNA varies more between people than any other part of our genome!
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After surgery, the person will need to take anti-rejection drugs called immunosuppressants. There are lots of different immunosuppressants and they work in different ways, but they all dampen your immune system to make it less likely to recognise that the organ has come from somewhere different. Usually, these drugs reduce the number of white blood cells because these are the ones that recognise antigens that don’t belong to your own body. Treatment with these drugs is the main therapy that people go through after transplant surgery.
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I don’t know that much about therapeutic cloning but, as far as I know, it’s a type of tissue engineering that researchers hope could replace transplants from donors in the future. So instead of waiting for a donor organ, scientists hope that one day we’d be able to take our own stem cells and use them replace the faulty tissue in our bodies. I think this is still in experiments – if any people were able to get this therapy, it would only be in very small clinical trials. We’re not at the stage yet where we can produce much tissue, so it’s definitely not a replacement for a donor transplant.
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The ‘invisibility cloak’ I’m working with hides donor cells and their antigens so they’re less likely to be attacked by the immune system of the patient. It’s a tiny bubble made of a chemical called alginate that’s ‘bioinvisible’. It lets nutrients into the cells and allows them to secrete insulin, but it blocks large immune cells and antibodies. This ‘invisibility cloak’ could be used for other transplants where a patient is missing a hormone or other chemical that can be secreted by cells. It’s important because, if there’s no chance of the patient’s immune system finding and attacking the donor cells, then there would be no risk of rejection and no need for the drugs.
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This matters in pancreatic islet transplants because the anti-rejection drugs can have side-effects that mean young people can’t get a tranplant. Creating an ‘invisibility cloak’ is way more complicated for organs like the kidney – their function depends on their blood supply, so I don’t know if it would ever be possible.

I’m sorry I’ve written such a long answer but I hope this answers all your questions!