43. The quest for better tests
New approaches to Lyme diagnostics with Victoria Sanderson.
In today’s podcast, Sarah speaks with Victoria Sanderson about her exciting new research into Lyme disease testing at the University of Guelph. Sanderson is a current medical student and previously completed her Master’s degree at the University of Guelph and became interested in Lyme disease after seeing how much the disease impacted her mother’s life and the lives of so many others. Having an acute interest in biology, she started to study Lyme disease and quickly became fascinated with its complex microbiology and pathology. She connected with the G. Magnotta Lab at the University of Guelph where she works with a team of world class researchers. You can find out more about the G. Magnotta Lab in this episode of the Looking at Lyme podcast.
Starting the process
Sanderson and her colleagues are looking at better ways of detecting Lyme bacteria, otherwise known as Borrelia burgdorferi. She explains the difference between whole blood, plasma and serum, and different methods of separating components of blood, including centrifugation and clotting. She points out that serum becomes separated when other components of the blood form a clot. Plasma is processed in a centrifuge, and clotting factors remain within the plasma. Samples were also processed to separate out various other components of the blood such as red blood cells or platelets.
“I saw firsthand how much (Lyme) can affect somebody, and their family, and I think that’s really motivated me in this work as well, and I see it affecting so many other people.”
Victoria Sanderson
Inside the lab
The current processes for directly measuring microbes in the lab are not optimal with Borrelia, the corkscrew shaped organisms called spirochetes. Sanderson describes the meticulous process of counting these spirochetes (sometimes thousands at one sitting) on a slide in order to estimate how many are present in each sample. Their research led to the important discovery that Borrelia was more easily detected when the platelet portion of the blood was used. This finding was true for direct detection,demonstrated using microscopy, PCR and protein-based techniques.
“We learned some really interesting things…we found that the platelet fraction that we separated out, was enriched with Borrelia after that mock infection. We were able to see it better under the microscope, we were able to detect the proteins that it produces better using a Western blot technique, and we were also able to detect it better in that fraction using PCR, which detects DNA.”
Victoria Sanderson
Direct and indirect testing
How does this process differ from the current testing? Sanderson explains that the current Lyme disease testing in Canada is designed to look (indirectly) at a patient’s antibody reaction to the bacteria rather than looking for direct evidence of the bacteria. In the past, it has been challenging to detect Lyme bacteria directly from blood samples. Sanderson points out that the ability to more easily detect Borrelia in different parts of the blood could have far reaching implications for researchers and ultimately for patients.
“The ingredients of an ideal diagnostic test are that it would be sensitive, which would help us avoid false negatives, it would be specific, to help us avoid false positives, and it would be incredibly helpful to have an indication of active infection and the disease stage. Is this an acute infection, is this post treatment, is this chronic? This would allow us to monitor disease progression as well as response to treatment.”
Victoria Sanderson
The role of anticoagulants
Another area of inquiry during their research was to examine the effects of anticoagulants used during blood collection on the bacteria. A search of the literature showed that there wasn’t a consensus as to which type of anticoagulant worked best (or none at all) for Lyme disease testing. In order to help answer this question Sanderson and her colleagues compared the growth of Borrelia in vacutainers coated with citrate, EDTA or no anticoagulant. The significant finding from this research was that EDTA significantly impeded Borrelia growth, making citrate the better option for laboratory testing. Sanderson refers us back to their literature search, which revealed that citrate has only been used in 11% of previous research!
“I think having a background in research and having those critical analysis skills and developing research questions will allow me to think really deeply about what I’m learning [in medical school] and how the research impacts patients directly.”
Victoria Sanderson
Next steps
Sanderson is very excited about future research pertaining to Lyme disease testing. She explains that their research involves “lab infected” blood samples, a process which involves growing Borrelia in culture in their lab, and adding it to blood from healthy patients. The advantage of using these samples is that researchers can control the amount of bacteria in each sample. She would like to start looking at blood samples from Lyme disease patients because these “natural” samples reflect what is seen in the population.
The value of better tests
So what makes a good diagnostic test? Sanderson explains that the best tests are sensitive (to help avoid false negative results), specific (to help avoid false positives), and ideally would be able to discern what stage of the disease a patient is in. Sanderson explains that this last aspect would help determine things such as disease progression and treatment response.
“I’m also just very inspired by the Lyme community. Everyone is so incredibly resilient and passionate, and I think seeing individuals and groups of people fight so hard against their illness and to ensure they’re properly cared for really inspires me in an advocacy role. Seeing all of this first hand, I think will help me in my future practice to be a really caring listener and to really look at the overall picture of a patient’s state of health, while also ensuring every patient feels heard and cared for as well.”
Victoria Sanderson
Critical thinking in research and clinical practice
Above and beyond the direct impact of these research findings, Sanderson points out that doing research and using her critical thinking skills enables her to better understand what she is learning and will have a direct impact on patients’ lives. Taking the time to learn about the challenges that Lyme patients are faced with has taught her the importance of listening to patients not only to obtain a better understanding of their overall health but also to make sure they feel heard and cared for. Thank you Victoria for sharing your ground breaking research with us. We look forward to hearing more from you in the future!
