The more time, the better the kidney
There are never enough donor organs. And the organs that there are have to be transplanted at lightning speed. Medical science is therefore working hard to keep organs viable for longer. Marlon de Haan (24) is researching how to keep kidneys alive outside the body.
Organ transplantation is a race against the clock. An organ has to be transplanted within 24 hours. It has to be removed from the donor, transplanted, checked and placed in the recipient. Marlon de Haan is researching how to extend this period for kidneys. ‘An organ is like an organism, with individual cells that all have their own energy needs,’ he explains. ‘Thus far we have reduced these energy needs by keeping donor organs on ice. Cooling slows down their metabolism.’
‘We’ve already managed to extend the life of a pig kidney as well as of a human kidney’
For his PhD De Haan is researching an alternative way of storing kidneys. Instead of cooling the kidney, it is kept in a perfusion system. ‘That is a kind of pump that can provide the organ with nutrients. By supplying the kidney with oxygen, sugar and proteins, we are trying to keep it alive longer – and ultimately to win more time for transplantation. We have already managed to extend the life of a pig kidney as well as of a human kidney that had been rejected for transplantation. This was for as many as four days. The first step has therefore been taken.’
More time is not the only advantage. ‘If there is any doubt about the quality of a donor organ, it is not used,’ De Haan explains. ‘But in a perfusion system, you have a longer period to assess organ function. If the initial doubt has been overcome and the organ proves to function well, it can be transplanted after all. And it is possible to condition an organ in the perfusion system. By making small adjustments, you can make the organ more suited to a specific recipient. This reduces the chances of rejection.’
It is already possible to preserve and condition some organs, such as the liver. But this is still a long way off for kidneys. ‘The kidney is one of the most complex organs in the body,’ De Haan explains. ‘That is because kidneys are made up of almost 30 types of cell. In comparison, a heart has around ten. Not only do all these cells have their own specific energy needs, but how they work together is also important. We are trying to find this out by experimenting with pig kidneys.’
Pig kidneys are often used for medical research because they are very similar to human ones in terms of their format, structure and appearance – also at a cellular level. De Haan and his colleagues collect the kidneys from the abattoir. ‘The situation has to be like a real-life transplantation,’ he says. ‘The organs are therefore quickly removed after slaughter and transported on ice. We go straight to the lab and start working with them immediately.’
De Haan finds it difficult to say where his fascination for organs comes from. ‘I think that a biology teacher at secondary school inspired me. She arranged for me to do a day of work experience at the cardiology department at Erasmus MC. And later on, my final project at school was about the heart. My bachelor’s research was also about the heart, about the idea of making a contractile heart tube.’
De Haan will receive his PhD before his master’s because internships were cancelled because of the pandemic. This did mean he had time to take part in this research project. ‘When you start this, you know that you can’t stay until the end,’ he says. ‘The research is only deemed a success when the application can be used in patients. You’ll never manage that within a four-year PhD. I do hope to remain indirectly involved in this research alongside my internships. And maybe I’ll return after I graduate; that depends on how much I like clinical medicine.’
What is regenerative medicine?
Regenerative medicine focuses on restoring the function of cells, tissues and organs after disease or damage. If one kidney no longer works, the only treatment alongside dialysis is transplantation. Research is being carried out into how to repair damaged kidneys or ‘grow’ kidneys from existing cells. In the future a personalised donor kidney could be grown from stem cells. But researchers are first looking at how to keep a kidney alive at all outside the body.
This article previously appeared on page 40 of Leidraad alumni magazine (in Dutch).
Text: Wilke Martens
Photo: Taco van der Eb