NEW STUDY. Researchers at Sahlgrenska Academy, University of Gothenburg, have devised a method for detecting injury to the central nervous system by examining blood plasma. The approach, which has been tested thus far on individuals with HIV-associated brain injury, opens the door to diagnosis of a wide range of neurodegenerative disorders without taking invasive samples of the cerebrospinal fluid.
While the level of the neurofilament light protein (NFL) in the cerebrospinal fluid represents a sensitive marker of neuronal injury, its clinical potential is limited by the need to perform lumbar puncture.
The method developed by the Sahlgrenska researchers is based on measuring NFL plasma concentration instead.
“We found that the method provides a highly sensitive biomarker of serious central nervous system injury in connection with HIV-associated dementia,” Professor Magnus Gisslén says. “We were also able to detect neuronal injury in HIV-positive individuals even when the symptoms were very discrete or as yet nonexistent.”
NFL leaks out of injured neurons and is measurable in the cerebrospinal fluid. The levels increase as the result of stroke, certain types of dementia and other neurodegenerative disorders.
“What we were able to determine is that NFL concentration in the plasma accurately reflects its presence in the cerebrospinal fluid,” Professor Gisslén says.
Previous research has established that NFL levels in the fluid are a highly reliable biomarker of neuronal injury. Published in EBioMedicine, the new study is based on examining plasma concentration to detect central nervous system injury in HIV-positive individuals.
A powerful tool
The biomarker is particularly sensitive because it can be quantified in everyone, whether or not they are HIV-positive or have a central nervous system condition. All human beings have a detectable, if normally low, concentration of NFL.
“Doctors will now have access to a powerful tool – the ability to diagnose neuronal injury in HIV-positive individuals without performing lumbar puncture,” Professor Gisslén says.
Additional studies are under way to explore the method’s potential for identifying and monitoring other neurodegenerative disorders.
“Plasma Concentration of the Neurofilament Light Protein (NFL) is a Biomarker of CNS Injury in HIV Infection: A Cross-Sectional Study” appeared in EBioMedicine online on November 22.