An interview with Professor Bernhard Boehm conducted by April Cashin-Garbutt, MA (Cantab)
Up until now, how was inflammation traditionally detected in diabetic patients and how long did this typically take?
As well as presenting with high blood glucose, diabetic patients have chronic low-grade inflammation, which can be measured by a range of inflammatory markers such as so-called high-sensitive CRP, TNFa and IL-6 as well as a full blood cell count.
These measurements use up to 5-10ml of blood and typically take about half a day to process, providing clinicians with information on the number of white blood cells and circulating biomarker concentration in the blood. But they shed no light on neutrophils, the immune system’s foot soldiers, and more critically whether these cells are functioning properly.
Neutrophil abnormalities have previously been reported in diabetic subjects, but are not routinely measured in clinical settings due to the laborious sample preparation required.
In our research, we found that patients with different neutrophil function responded differently to drug treatment. So making this additional information readily available will help to improve treatment for patients.
Can you please give an overview of the new kit that has been developed to allow doctors to find out in minutes whether a diabetic patient is suffering from inflammation?
Capitalising on the different sizes of blood cells (which range from 8microns to 10microns), this new lab-on-a-chip device, which was developed by Dr Hou Hanwei, a senior research fellow at LKCMedicine, with inputs from our colleagues at NTU’s School of Mechanical & Aerospace Engineering, effectively and accurately sorts blood cells purely by size, enabling us to isolate neutrophils within minutes.
After this very gentle isolation procedure, we can study their rolling functions in a microfluidics format at a single cell level. Only a drop of blood is needed and total separation and assay time requires approximately 20 minutes.
Not only does this device reduce the processing time, it is also a “no touch” method which does not require antibody binding or centrifugation and thus ensures minimal interference with these highly sensitive neutrophils.
Conventional methods to isolate neutrophils require density-gradient centrifugation and multiple washing steps, all of which can alter the state of the cells. This means that the body’s first line of defense has so far been a very little studied mechanism.
With our new device, we have overcome this challenge and have started to study neutrophil function in diabetes in greater detail and what effect that may have. Using a label-free isolation approach means we can do away with adding expensive antibodies, making his lab-on-a-chip cheap as chips.
In our study, as mentioned, we have shown that patients with similar cell counts, but different neutrophil function, respond differently to the use of standard anti-diabetic drug treatment. With this additional information, patients can be stratified more accurately and receive a better tailored treatment earlier, which is vital in avoiding long-term adverse health outcomes, such as myocardial infarctions and stroke.
A short soundbite and demonstration of the device, is available via the below link. Please credit The LKCMedicine, Lee Kong Chian School of Medicine, NTU:
The LKCMedicine, Lee Kong Chian School of Medicine, NTU
Why is it important to be able to detect inflammation quickly?
First of all, it is important to recognize that diabetes is not just a disease of high blood glucose.
It is a multifaceted syndrome that is about high blood glucose, high lipids, high blood pressure, unhealthy diets leading to increased levels of glycotoxins, lack of excise and oxidative stress, all of which trigger danger signals in the body, which in turn activate the immune system including neutrophils.
This chronic low-grade inflammation has been clearly linked to a higher risk of cardiovascular events, such as stroke and myocardial infarction.
In diabetes, early and appropriate treatment to effectively manage the condition has been shown to have a positive legacy effect, reducing the risk of complications such as cardiovascular events in the long term.
But at the moment, we effectively use very costly and time consuming evidence-based trial and error approaches to find the optimal treatment for patients.
How does the test work?
Using a finger prick of blood (50-100μl), the red blood cells are lysed before the remaining cells are pumped into a spiral microchip.
Relying on the naturally occurring hydrodynamic and centrifugal forces within the channel, cells are sorted by size, migrating to distinct positions within the channel.
The sorted cells are then extracted via different outlets – two for waste, remnants of lysed red blood cells and platelets, another for lymphocytes and one for neutrophils.
Dr Hou Han Wei, Lee Kong Chian School of Medicine, NTU
Dr Hou Han Wei, Lee Kong Chian School of Medicine, NTU
What stage of development is the test currently at?
We went through a series of prototypes before arriving at the final design of this device, which has been validated, and is now being patented.
We are now working on incorporating the isolation and analysis into a single bench-top device that can be deployed in healthcare institutions and clinics.
At the same time, we tested our hypothesis that neutrophil function is affected in diabetes with an initial sample size of 32 and showed that neutrophils in people with diabetes roll at speeds 20% faster than in healthy subjects. With this novel test system we can directly monitor neutrophils’ competence in integrating signals received from their environment.
We are now looking to validate those findings in a large-scale clinical trial. Hopefully, this will enable us to use these rolling speed measurements to identity diabetic patients at high risk of inflammation quickly, leading to earlier start of the right treatment.
What were the main challenges in developing the test?
Neutrophils are the most abundant white cells in our body and perform a variety of functions during inflammation. Right now, we focused on the first step in neutrophil response, which is the cell rolling in blood vessels. This determines the number of cells which eventually get recruited to “fight” the source of inflammation.
It is well known that there is a lot of cell heterogeneity even among the same cell type. Hence it is important to measure cell rolling for every cell which is not trivial.
We have developed an automated algorithm to track the cell movement which enables us to have hundreds of speed measurement quickly. This is key to defining and further charactering how neutrophils are integrating signals from their environment, in particular in a disease state such as diabetes, and how their behavior can be modified by drugs.
What impact do you think the test will have on diabetes management?
Our device has been designed for point of care testing. With our rapid testing method, patients can get their inflammation status, which covers a spectrum from low- to high-grade inflammation, checked and their treatment adjusted in the same visit, rather than have to come back for a repeat visit when the results are available.
Prompt adjustment of medication or dosage will in attaining better management faster and will thus have long-term health benefits. This is particularly crucial at a time when especially in Asia, we see complications from diabetes continuing to rise.
With this additional information, clinicians can better decide what drugs (or dosage) are most effective for an individual based on functional responses. Clinically, this will lead to saving time and cost for better health management of diabetic patients.
What are the next stages for the development of the test?
Next, we are planning a larger clinical validation study that we expect to complete in the next three to four years. We hope to study neutrophil functional states in diabetic patients and follow their changes with patient follow up to see if they can be correlated to clinical outcome. We will also explore other neutrophil functionalities such as migration and adhesion to see if they are affected in diabetes.
At the same time we will work on integrating the neutrophils isolation and assay modules into one single diagnostic machine.
What do you think the future holds for detecting inflammation in diabetic patients?
Just as self-monitoring of blood glucose has transformed our understanding of what a well-controlled blood sugar profile should look like, we hope that self-monitoring of one’s inflammatory status will be possible one day. We have developed a tool that allows better analysis of patient’s inflammatory status and we hope that one day, this point-of-care device can be translated into a self-monitoring device that empowers patients to control their condition even better.
Unlike blood cell count, immune cell function can change within minutes when exposed to drugs, chemicals or other challenges such as diet or exercise. Hence, we hypothesize that this new idea of profiling inflammation using cell function is more sensitive and even suitable for real-time monitoring.
Of course, it can be argued that other pathological states (e.g. infections) can also cause inflammation which will in turn affect immune cell function. Hence, we will include more functional parameters to better distinguish diabetes, as well as characterizing other immune cell type (monocytes) which are implicated in diabetes.
With the ability to detect inflammation, we hope to stratify high-risk patients, so that downstream or more specific tests can be performed on this subgroup. This will improve healthcare management of diabetic patients in terms of cost and efficiency.
Where can readers find more information?
https://www.ncbi.nlm.nih.gov/pubmed/27381673
About Professor Bernhard Boehm
Professor of Metabolic Medicine and Scientific Director of Metabolic Disease Research Program, Lee Kong Chian School of Medicine, Nanyang Technological University
Professor Bernhard Boehm graduated in Medicine from the Johann Wolfgang Goethe-University in Frankfurt am Main, Germany in 1985.
He then joined the Department of Internal Medicine at the Johann Wolfgang Goethe-University Medical Centre in 1985.
He received the Board Certificate in Internal Medicine and the Board Certificate in Endocrinology and Diabetology given by the Chamber of Physicians State Hesse, Germany, in 1992 and 1993 respectively.
Professor Boehm was appointed as Full Professor of Internal Medicine and the Head of the Division of Diabetes, Endocrinology and Metabolism as well as the Director College for Nutritionists, Ulm University Medical Centre in 1993. Professor Boehm was nominated to act as the Dean (Graduate Medical Studies) of Ulm University from 2006 to 2009.
Besides his main duty as the Dean of Graduate Medical Studies, Prof Boehm holds several concurrent positions, these include:
- Vice-President of the International Graduate School in Molecular Medicine of Ulm University (2004- 2013)
- President of the DFG funded Graduate School of Molecular Diabetology and Endocrinology (2005-2013)
- Vice-President of the DFG funded Initiative Program on “Pancreatic diseases” (1999-2011)
Award and Grants:
Professor Boehm was the recipient of several professional awards including the prestigious Ernst-Friedrich Pfeiffer Award by the German Diabetes Association in the year 1995.
Professor Boehm was the recipient of several professional awards including the prestigious Ernst-Friedrich Pfeiffer Award by the German Diabetes Association in the year 1995.
In the field of Translational Medicine, Prof Boehm has made seminal contributions to the field of diabetes and metabolic medicine. His research work has received generous funding from the German research Council (DFG), the Ministry of Sciences of Germany (BMBF), the European Commission, the Juvenile Diabetes Research Foundation International, U.S.A., and the National Institutes of Health, U.S.A.
Prof Boehm has initiated several cohort studies specifically define the genetic and epigenetic basis of islet cell autoimmunity; and describe several key environmental factors that drive the autoimmune destruction of the insulin-producing cells of the pancreas. He defined a panel of novel disease-associated biomarkers including glycotoxins linked to the low-grade inflammation in vascular complications, the development of fatty liver disease and beta cell decompensation.
The cohorts were financially supported by European Commission as well as industry partners such as Sanofi-Aventis, Boehringer Ingelheim, Novo-Nordisk and Fresenius Kabi.
In the field of Genetic Epidemiology, Professor Boehm has significantly contributed to elucidate the genetic basis of micro- and macrovascular complications in various patient populations.
Scientific Publications:
Prof Boehm has published more than 400 papers in the internationally peer-reviewed journals. His work is extensively cited in the scientific literatures in the field of diabetes, endocrinology and metabolism, especially in the emerging field of immune-metabolism. He is the editor of several textbooks in Diabetes mellitus and Clinical Chemistry and has acted as the co-editor of several international journals.
Upon joining the LKCMedicine, Professor Boehm has initiated several interesting studies to apply novel animal models of experimental autoimmune diabetes to pinpoint the cross-talk between immune cells and insulin-producing ß-cells.
Dietary inflammation linked to higher mortality risk in coronary heart disease patients