PET Scanning to Measure Beta Cell Mass
An Interview with Paul Harris, PhD.

He is well known for his experimental work with Positron Emission Tomography (PET) technology - originally developed to follow pathways in the brain - as a way of imaging insulin-producing beta cells in the pancreas. “Imaging is a means to an end,” said Paul Harris, PhD, a scientist at Columbia University’s Naomi Berrie Diabetes Center. “It’s a tool, really – an innovative way of tracking beta cell mass and function. There are many ways to do this -  imaging of this type happens to be one of the most precise ways.” 

Recently, Dr. Harris - who has an undergraduate degree from UC Berkeley in biophysics, a graduate degree from Cornell in Cell Biology and postdoctoral training in peptide chemistry from Rockefeller University - talked about the growing field of beta cell imaging and the role it might one day play in the treatment of both T1D and T2D.  He started by setting the record straight:

“Everything I do, I do with my wife,” said Dr. Harris of his partner and colleague, Antonella Maffei, PhD, with whom he has worked since 1995. “So it’s never just me, it’s us. And when we’re not arguing about results, we’re actually enjoying doing this.”

Where did the idea of trying to image pancreatic beta cells come from?

We were working with a friend, a surgeon at Columbia, who was doing islet transplant studies. Doctors were unhappy then (and still are) with the current tools available to measure the status of beta cells in the pancreas. Current insulin measurements alone aren’t very reliable.  We thought, wouldn’t it be nice if we could actually, quantitatively measure the islets in vivo - that is, from within a living organism - by imaging the pancreas. So far, imaging is much more precise than any other known method.

Doesn’t most of medicine use imaging as a tool? Did this help you get started?

Actually, all of our PET imaging work directly relies on techniques developed by people who have already, quite successfully, imaged the brain.  We’ve used their molecules and their targets. We’re pretending that the pancreas is a brain. And so far, it’s proving to be a very precise measurement tool.

What is the benefit or promise of imaging?

With some measurements of insulin, by the time a person shows signs of insulin dependence, they’re already in deep trouble. With imaging, we have a proactive way of following the progression of beta cells, which allows for earlier intervention and better outcomes.

Do you imagine a day when doctors send their patients for PET scans to proactively diagnose diabetes?

We are currently studying whether our probes are sensitive enough to detect small changes in a single patient.  We’ve already demonstrated that, by using the power of multiple individuals in a single study, this PET technology is probably sensitive enough to allow detection of clinically relevant changes in beta cell mass, making this technology ideal for diabetes drug development.  Preparing more sensitive probes is a future research direction.

Click here to read more about Dr. Harris’s research.