Taking blood samples at home after an organ transplant

Frequent hospital check-ups will soon be a thing of the past for patients who have undergone an organ transplant, as they will be able to take samples of their own blood at home and send them off for analysis. This is the conclusion of Remco Koster, researcher-analyst in the UMCG, in a thesis for which he will be awarded a PhD by the University of Groningen on 25 September 2015. ‘My research revealed the limitations of various methods of analysis,’ he explains. ‘But the Dried Blood Spot (DBS) method appears to be highly suitable for home monitoring by patients.’

Patients who have undergone an organ transplant have to take drugs to suppress the body’s immune system for the rest of their lives. The drugs are intended to prevent the body from rejecting the new organ. ‘The dosage is very specific’, continues Koster. ‘Too much or too little can be dangerous, so patients have to go to hospital regularly to monitor the level of the drug in their blood.’

Blood on a card

The Dried Blood Spot (DBS) method seems to have solved this problem. ‘Patients can prick their finger at home and squeeze a drop of blood onto a special card. Once the blood has dried, they send the card to the hospital. The sample is then analysed in the laboratory, where a pharmacist and doctor decide whether the dose needs to be altered.’ It saves patients time, travelling expenses and a lot of bother.

Limitations

DBS is not a new method. ‘As far as we know, no solid research into the limitations of the method has ever been carried out.’ So this is what Koster did. ‘Every analysis method has advantages and disadvantages, whether you are analysing blood, sweat or hair. My PhD research project involved trying to map these advantages and disadvantages. Identifying the factors that limit a method and affect the results allows you to improve the quality of the analyses.’ Koster also studied various factors influencing the DBS method, such as the type of DBS card used , the effect of the viscosity of the blood and the type of drugs in the blood. ‘Having identified the limitations of the DBS method, we are now confident about putting it into practice.’

Start in 2016

The method will be used from 2016 onwards. The first group of patients to take their own blood samples will be patients taking Tacrolimus, a drug commonly prescribed after an organ transplant. The instruction films and texts have already been compiled. ‘We will start with double measurements, so that we can compare DBS readings with the readings we would normally derive from blood-in-blood tubes.’ But patients will still have to come to hospital. ‘Patients who have undergone a transplant will still have to come to hospital to be checked for other matters, but not as often.’ Koster wants transplant patients who take other drugs to start taking their own blood samples in the course of 2016.

Tuberculosis

DBS may also play a major role for another category of patients. ‘In countries where tuberculosis is prevalent, such as Vietnam or Eastern Europe, patients are barely monitored at all. Using DBS, doctors can monitor their patients from a distance and ensure that they are taking the right dose of their medication.’ Researchers are already using the method. ‘Researchers working with another country can arrange for blood samples to be taken in that country and analysed here in the Netherlands.’

Curriculum Vitae

Remco Koster will be awarded a PhD by the University of Groningen for a thesis entitled The influence of the sample matrix on LC-MS/MS method development and analytical performance . Koster studied Analytical Chemistry at Saxion University of Applied Sciences in Enschede. He has worked as a Research Analyst in the Clinical Pharmaceutical and Toxicological Laboratory in the Department of Clinical Pharmacy and Pharmacology of the UMCG (University Medical Center Groningen) since 2005. In addition, since 2012 he has been carrying out PhD research in the University of Groningen ’ s Institute for Drug Exploration GUIDE, as part of a Biopharmaceuticals research programme entitled: Discovery, Design and Delivery. His supervisors are Prof. D.R.A. Uges and Prof. J.W.G. Kosterink.