‘Seeing’ Protein Density in Blood May Help in Early MS Diagnosis by Subtype, Work Suggests
A way of detecting the density of proteins in the blood, called “magnetic levitation” or MagLev, may aid in more quickly diagnosing chronic diseases, including the particular type of multiple sclerosis suspected in a person, the scientists who developed this method report.
Plasma, the liquid component of blood, is composed of various proteins with important roles in the body. Fluctuations in the levels of these proteins are associated with different diseases.
For this reason, being able to precisely quantify the density of blood proteins can have important ramifications, but reliable methods have eluded scientists.
A team with the Precision Health Program at Michigan State University (MSU) now report developing, and having successfully tested what they call the MagLev method, and publishing two studies show how MagLev can be used on plasma.
“When we put something in liquid, it separates into sediment by weight,” Morteza Mahmoudi, PhD, an assistant professor at MSU, said in a press release. “But another force — the magnetic force — can cancel out weight and levitate the proteins. This permits us to much more precisely define the density of proteins in solution.”
MagLev can separate various types of proteins in solution according to their relative densities, instead of weight.
In the first study, titled “Magnetically Levitated Plasma Proteins” and published in the journal Analytical Chemistry, Mahmoudi’s team applied MagLev to a small tube containing magnetic nanoparticles and plasma proteins. Over the course of three hours, researchers noticed the appearance of several distinct bands representing different types of proteins.
“The proteins created specific shapes when they were levitated,” Mahmoudi said. “It looks like a ‘smiley face’ of layers.”
This study showed that no relationship existed between protein density and protein molecular weight, and that the average protein density was lower than previously thought.
Exactly how (the mechanism through which) protein separation occurs based on density is not clear. Researchers speculate it might be linked to structural differences and/or protein-to-protein interactions.
“The findings are of crucial importance, as protein density is being used to define proteins’ physical properties, including their 3D structures,” Mahmoudi said. “In addition, the accurate density of proteins enables us to design safer and more efficient therapeutic agents, such as nanomedicine.”
MagLev may be useful both to researchers and doctors in the clinic, the team suggested, as the characteristics of a patient’s plasma proteins can inform a physician about that person’s health.
The second published study, “Evolving Magnetically Levitated Plasma Proteins Detects Opioid Use Disorder as a Model Disease” that appeared in the journal Advanced Healthcare Materials, supports this idea.
Here, researchers evaluated MagLev in a clinical setting by comparing plasma from two groups: healthy individuals and people with opioid use disorder.
They identified distinct alterations in the range of plasma proteins between these groups. For example, people with opioid disorder had higher expression of specific variants of hemoglobin (a protein in red blood cells that carries oxygen).
“The observed differences within each subject group might be related due to the known interactions of opioid drugs with plasma proteins, which in turn could affect their levitation characteristics,” the researchers wrote.
Based on this and other results, the team believes that MagLev is a promising new method for diagnostics.
Mahmoudi’s team is testing MagLev’s ability to identify chronic diseases like MS and cancer, where a correct diagnosis is essential to an early start of proper treatment.
“There are four subtypes of MS, but diagnosis is currently based on the patient’s behavior, symptoms, and his or her response to treatment,” Mahmoudi said. “There is no biomarker or MRI [magnetic resonance imaging] test to diagnose the different subtypes at the early stages.
“Correctly diagnosing the type of MS is critical, since it dictates which type of treatment is appropriate,” he added. “We hope this MagLev method will give clinicians a technique to define the subtypes.”