‘We still do not know it and therefore we need to study it’

Nederland, Leiden 25-6-2010, . Jean-Louis Kerkhoffs foto; Ineke Oostveen

Jean-Louis Kerkhoffs

Jean-Louis Kerkhoffs is a hematologist in The HagaZiekenhuis in The Hague and a senior researcher at the Department of Clinical Transfusion Research at Sanquin as from 2004. In May 2012 he finished his PhD ‘Efficacy of platelet transfusions’. He is a specialist in the areas of platelet research, sickle cell disease and therapeutic aphaeresis.

Can you tell us something about your current research here at Sanquin?
Currently I am working on two studies within Sanquin. My main project is a large international clinical study on the clinical effects of Mirasol-treated platelets, which is used to inactivate pathogens in platelets. The study is being done in four hospitals in the Netherlands and now also in four Canadian and one Norwegian hospital. It’s a very large project because we need to enroll at least 600 people to have high-quality and significant results. This means a lot of work on a communicative, contractual and legal base, nevertheless the clinical work is very intensive too. At present we have included 220 patients. The aim is to be ready at the end of 2014 / the beginning of 2015; and after that it becomes exciting to see what the results will signify.
Furthermore, I am involved in setting up a post-marketing study in which we want to examine the safety and efficacy of platelet transfusions in the Netherlands. This is basically a large nationwide study by two PhD students. We need involvement of the Department of Transfusion Medicine of Sanquin because a large network must be developed to include all the hospitals, which is quite a challenge.

Why are platelets important for our health?
People with a disease of the bone marrow which do not make platelets have problems with clotting. This is due to weakening of the vessel wall. There is not an absolute threshold of platelets, but the lower the number the more a patient will bleed, especially when there is damage made by chemotherapy. When you do not treat these patients, there is a possibility of severe bleeding. In order to increase coagulation and reduce the risk of a severe bleeding such as a stroke or other live-threatening bleeding, we treat the patients with a platelet transfusion.
I personally like this field a lot because it shows the link between the patients and Sanquin. Actually, this is somewhat the reason why I got into research in the first place. I consider the studies that we do not only as a product but I also link a lot of patient-related questions to it. For me it is really an integration of my hobby with patient care, and that is nice.

Besides coagulation problems, are there any other problems that can occur?
An issue that occurs is that we don’t know if platelets function after a transfusion; we only know that the concentration of platelets rises. The main question is how to measure the function of these transfused platelets; however we have no tools to do this. In the past we measured the bleeding time by making small wounds on the arm of a patient and timed the bleeding with a stopwatch. We now know that this has absolutely no predictive value whatsoever and moreover, patients did not really like the test as you can imagine. We have since invented all kinds of tests to measure the functionality and there are a lot of devices on the market, but to my knowledge there is no device that can generate a good predictive value to reflect the actual bleeding tendency of a patient.

What are the most important lines of research/approaches that have developed in your field over the past 5 or 10 years?
In the past five to ten years not much has changed. The field of platelets really developed in the sixties and seventies when it all started with the removal of white blood cells from the blood products to prevent development HLA antibodies.
A more recent important development is it increasingly replacing plasma with an additive solution, which has all sorts of advantages. For the blood bank there is an economic advantage because you can use the plasma for other products. For patients it has the advantage that they are less likely to develop a transfusion reaction because all kinds of material like proteins that cause these reactions are extracted. However, platelets survive best in plasma; therefore it is a challenge to find the right storage solution.
Another development, regarding a safety issue, is whether you want to apply pathogen reduction to the product besides all the virus tests we already do. In the Netherlands we are studying this but in some countries like Switzerland, Belgium, France and Spain this is already implemented, at least in part.

What is, according to you, the biggest challenge in current research in your field?
To actually predict which patient will be helped with a platelet transfusion and for which patient you may have to choose a different strategy to reduce severe bleeding I think is the biggest challenge. You must realize that despite the fact that we transfuse platelets to many patients, we still see a lot of bleeding. This might be because we started too late with the treatment or we need to give higher concentrations to patients; but we do not know that therefore we need to study this.

Why does your line of research matter? Why should people put money into it?
Supportive care is essential for people with malignant diseases such as leukemia and a quite poor prognosis. These patients depend on the amount of chemotherapy they receive and that all stands or falls with excellent support of care. In my opinion, if you get better in supportive care, which also includes transfusions, you can maybe improve in a sense the survival of cancer, and a better quality of the survival. So therefore it is important to invest money in this research.

Who or what will benefit from your research?
The patient care will benefit for the most part. However, in my opinion the blood bank and the government will eventually also benefit from my research. If you handle your sources more focused and efficiently, you create both an economic as well as a safety benefit. So I think a lot of parties will benefit from my research but I hope initially the patients do.

How does your research suits Sanquin?
Sanquin is the organization in the Netherlands responsible for safety and efficacy of blood transfusion. There is no other organization in the Netherlands that is more involved with blood transfusions; from donor to patient. Sanquin is the organization of choice to monitor the entire chain very well and improve where possible. So I think Sanquin is essential for that part.
What could be improved is the connection with the departments in hospitals. We want to be closer to the patient by gaining insights in all the data concerning blood and blood transfusion. However, because each hospital has its own way of collecting patient information this is very difficult. So it is a challenge to improve data registration and make it more efficient, and I hope that this improves in the future because I think we have a lot to gain in that area.

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