After an organ transplant, patients need regular hospital visits for check-ups and blood tests. Especially during the first year, these visits can be frequent. Depending on the transplanted organ and the patient’s recovery, the number of visits can rise to around forty per year.

Within the Convergence Health & Technology Flagship Organ Transplantation Erasmus MC, TU Delft and Erasmus School of Health Policy and Management are exploring how transplant care can better fit into patients’ daily lives. They combine at-home blood sampling, software for personalised medication dosing and digital home monitoring. 

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Why the right dose matters

After a kidney, heart, lung or liver transplant, patients take medication to prevent rejection of the donor organ. Tacrolimus is one of the key medicines used for this purpose. Getting the dose right is crucial. Too low a concentration increases the risk of rejection, while too high a concentration can cause serious side effects and organ damage.

The right dose differs from one person to another and can also change over time. Factors such as age, genetic characteristics, other medication and a patient’s health status all play a role. This is why patients need regular blood tests to monitor the amount of tacrolimus in their blood.

Blood tests usually take place in hospital or at a blood collection centre, which may be far from home. The timing of the sample is also important to reliably assess tacrolimus levels. Delays while travelling or waiting at the blood collection centre can therefore make this more difficult.

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A few drops of blood by post

With dried blood spot monitoring (DBS), patients can collect a few drops of blood themselves at home using a finger prick. They apply the blood to a special card and, once it has dried, send it to the laboratory by post. There, researchers can measure, among other things, tacrolimus levels and certain indicators of kidney function.

DBS is already used at Erasmus MC for kidney and heart transplant patients, while parts of liver transplant care are also beginning to make use of the method. It can replace some regular blood draws. DBS also makes it easier to collect blood at the right time and to take samples at several different time points. This can provide a more complete picture of how the body absorbs and breaks down tacrolimus.

Software for personalised dosing advice

Alongside DBS, the team is developing software to help clinicians determine the most appropriate dose of tacrolimus. The programme combines patient characteristics and previous blood measurements with pharmacological models. It can then predict which dose is likely to be needed to reach the desired concentration. As new blood test results become available, the advice can be updated. This means treatment does not only respond afterwards to levels that are too high or too low, but can also become more predictive.

An earlier study illustrates why this is promising. With model-informed dosing, 58 percent of kidney transplant patients reached the target blood concentration at the first steady-state measurement. In a separate study group, where the starting dose was based only on body weight, this figure was 37.4 percent.

Whether this approach also leads to fewer rejection episodes, fewer side effects or less organ damage still needs to be investigated. The software is therefore still being tested and must be validated and certified before it can be introduced into routine care.

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Fewer trips to Rotterdam

Alongside blood testing and medication dosing, digital home monitoring is another important development. Patients can measure values such as blood pressure, temperature, oxygen saturation and weight at home. Healthcare professionals can monitor these data remotely and conduct some follow-up appointments by video.

For heart transplant patients, after the intensive first year, two of the four annual check-ups now typically take place remotely. For patients and their families, this means less travel and less time spent on hospital visits. This can make a major difference, particularly for people who live far from the transplant centre.

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Technology only works if people can work with it

The success of home monitoring and personalised dosing depends on more than technology alone. Patients must also be able and willing to use it. According to Dennis Hesselink, an estimated 30 to 40 percent of transplant patients do not always take their medication exactly as prescribed over time. In a living lab, researchers are therefore working with patients and a psychologist to explore what types of support may help. For one patient, a digital reminder may be enough, while another may benefit from more personal guidance.

Patients and healthcare professionals have also been interviewed about their experiences with and expectations of home monitoring and self-management. What benefits do they see? Where do they perceive risks? And how much responsibility are patients willing and able to take on themselves? These insights help the team design the technology in a way that fits everyday practice

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The economic perspective

The economic impact is also being studied. An earlier Dutch study estimated a potential saving of €399 per patient during the first six months after kidney transplantation. This estimate assumed that DBS would replace regular blood draws and that one hospital visit could be avoided.

If DBS is added on top of existing care, however, cost savings are not automatic. Researchers from ESHPM are therefore also looking at the broader impact on patients and their families, including travel time, absence from work and the involvement of informal caregivers.

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The next step: care that better fits patients’ lives

The ultimate goal is transplant care that fits more naturally into patients’ daily lives. By combining blood sampling, home monitoring and personalised dosing software, patients can gain more control over their treatment. They do not need to travel to hospital for every blood test or check-up, while healthcare professionals can still monitor their health closely and tailor treatment more precisely.

Some of these technologies are already in use, but further steps are needed before they can be safely connected into one integrated approach. DBS cannot yet replace every blood draw. Sending and analyzing samples takes time, and not all required blood values can be measured using DBS. Especially shortly after transplantation, when medication doses may need to be adjusted quickly, conventional blood testing therefore remains important.

The personalized dosing software is also still being tested and must be validated and certified. For home monitoring, one of the main challenges is organising care around the technology. Clear agreements are needed, for example, about who reviews the measurements and when action should be taken.

By further developing both the technology and the surrounding care processes, the researchers aim to safely bring these elements together in everyday transplant care. The work initially focuses on kidney transplantation. If the approach proves safe and effective, it may also be applied to other organ transplants and transplant centers in the future.

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