Thanks to stem cell donors like Jesper, Eefje is still alive

Eefje Franssen (24) was already planning to study at TU Delft in 2020. She was then living at home in Zeeland, studying architecture at the university of applied sciences in Vlissingen, and was to start a minor in architecture at TU Delft in September. She thought that the horrible headache that she suffered would be gone by then.

But things went differently. After a blood test, it turned out that Eefje’s blood levels were so bad that she was hospitalised immediately. A bone marrow puncture showed that her body was virtually prevented from producing new blood cells. The diagnosis was aplastic anaemia, a serious type of anaemia. It is only diagnosed 45 times a year in the Netherlands. The cause was unknown, it was simply very bad luck.

In the period thereafter, Eefje was given blood transfusions through an intravenous drip to keep her blood levels acceptable. “But they quickly said that this was untenable and that they wanted to arrange a stem cell transplant.” She let it all wash over her. “I was in survival mode and thought that they should just do whatever was needed. Just make sure that I get better, I thought.”

Looking for a match

According to Matchis, in 2025 there were more than 600 searches for a match for a Dutch patient who needed a stem cell transplant. Matchis is the organisation that recruits, registers and helps stem cell donors in the Netherlands. The patients are people like Eefje in 2020 whose own stem cells do not function properly.

They usually manage to find a suitable donor, says Matchis’ spokesperson Bert Elberse. That said, Matchis raised the alarm. The reason is that the people on the donor register are aging, leading to a drop in the number of potential suitable donors. Matchis is running various action campaigns to try to recruit new donors.

Once you reach the age of 56, you are automatically removed from the register. The younger the better, and this is certainly the case for stem cell donors. The risk of complications increases the older the donor is. Registering at Matchis is thus only free of charge if you are below the age of 35. Potential donors above this age pay a contribution of EUR 35.

Small chance of being called up

There are currently 425,000 registered stem cell donors in the Netherlands. In 2025, up till now, only 213 of them have donated stem cells. The chance that you are invited to donate stem cells is thus very small. As the donor banks across the world are connected, the stem cells do not automatically go to a patient in the Netherlands. Worldwide, there are 42 million donors, most of whom live in the West.

To be able to supply a few hundred patients with donated stem cells, the register has to be enormous, says the Matchis spokesperson Elberse. In the best case, the patient and the donor share the same tissue type. This alone is rare. Add other factors, such as the age of the donor, and the number of suitable donors drops.

Best match

Jesper van der Marel (25, Mechanical Engineering master’s student) is one of the 425,000 Dutch people on the stem cell donor register. He registered in 2018. “I’d already forgotten I did so.” Then, five years later, Matchis phoned him. Jesper is one of four potential matches for a patient. “My immediate thought was that I do it. How amazing it is that you can save someone’s life.”

‘How amazing it is that you can save someone’s life’

After a blood test and three months of waiting, the telephone rang again. Standing in the Hydro Motion workshop, the TU Delft student team which Jesper is part of that year, a Matchis employee told him that he is the best match for a certain patient. Jesper did not hesitate for a minute.

After a lengthy conversation with Matchis which covered all the ins and outs of the process and a medical examination, a few weeks later it was time. At the Leiden University Medical Centre Jesper was anaesthetised and underwent a minor operation in which the doctors removed some stem cells from his bone marrow. Anaesthetic is used in 15% of the donations. In the remaining 85% it is not needed as only blood is taken.

Looking back, he says that the procedure was not that bad. “I was out of the running for one day, and tired for another couple of days,” he says. “And one-and-a-half weeks later I went to Monaco with the Hydro Motion Team. It was a tense time!”

Donor found

The search for a stem cell donor started with Eefje’s older sister. Statistically, the immediate family is the highest chance of a match. When it turned out that she was not a match, the search continued in the stem cell donor register. In the summer of 2020, a couple of months after she had heard that she had a medical condition, Eefje heard that a donor had been found.

The transplant was done in September. It was a relatively simple procedure whereby Eefje received the donor stem cells through an intravenous drip. But the preparation was heavy. The donor cells will only be accepted by the body if the entire immune system is shut down. This meant two weeks of intensive chemotherapy followed by radiation therapy which damaged her bone marrow to such an extent that space was created for the new stem cells.

‘Anyone who came in had to wear a special suit’

A dysfunctional immune system makes you vulnerable to any virus and bacteria. Eefje thus lay in an isolation room in the hospital for four weeks. “Anyone who came in had to wear a special suit,” she remembers.

One week after the transplant, Eefje’s blood values were improving and two weeks after that she could go home. As her immune system was still weak, she had to be careful for months, and certainly with the Covid virus that was doing the rounds then.

Architecture master’s

Now, in 2025, things are going well with Eefje. She did not do the planned minor, instead, she is doing a master’s in Architecture at TU Delft. She does not need to take the medicines anymore that she took in the first few months to prevent her body from rejecting the new stem cells. A check-up is done only once every six months.

She is fascinated by the thought that her blood group has changed. “That that happens in your own body!” Given her medical history, she cannot donate stem cells or blood. But she hopes that her story encourages other people to become donors.

‘Stem cell donation is a selfless act’

Elberse, the Matchis spokesperson, hopes so too. He says that students are an important target group. “They are young, healthy and often socially engaged.” Matchis is targeting students through activities like student campaigns in collaboration with student associations.

Letter to donors

You give or receive a stem cell donation anonymously. But both the patient and the donor can write a letter to each other. Jesper did so a year after his donation. “It was a little scary as you do not want to invade someone else’s private life.” But curiosity got the upper hand. And when he received a reply, it affected him more than he thought. “He wrote that he was grateful that he could see his child grow up. It’s amazing that I could give him that opportunity.”

Eefje too wrote a letter to her donor. She says that it was hard to put down her feelings in words. “You write to an unknown person that acted out of the kindness of their heart. Stem cell donation is a selfless act. It is such a powerful thought that I am still walking around thanks to that person.”