Non-invasive Biomarker for the Diagnosis of Progressive Multifocal Leukoencephalopathy

Life Sciences : Diagnostics

Available for licensing


  • Christopher Sullivan , University of Texas at Austin
  • Chun Jung Chen , University of Texas at Austin

Background/unmet need

Monoclonal antibodies (MAbs) have exploded into the market as a major new drug technology, which is expected to grow rapidly in upcoming years. Some of these MAbs are associated with an increased risk of Progressive Multifocal Leukoencephalopathy (PML), a highly lethal encephalitis caused by the John Cunningham Virus (JCV) crossing the blood-brain barrier. A non-invasive biomarker for PML is greatly needed in order for these monoclonal antibodies to continue to be administered safely.

Finding a biomarker has been difficult in the past, as JCV is non-symptomatic unless it crosses the blood-brain barrier. The presence of viral particles or antibodies is not sufficient to diagnose PML, as 50 to 80 percent of all people have been exposed to the virus. Testing for the presence of virus in the brain is the gold standard for diagnosis. But such testing requires the invasive procedure of collecting cerebral spinal fluid and is therefore not suitable for routine detection and monitoring.

Invention Description

This technology provides an easy and non-invasive method for monitoring and detecting PML, potentially allowing this ailment to be caught in early stages before brain damage can take place. This new procedure is simple, cheap, and non-invasive. Testing can be performed on serum, blood, and potentially even urine.

This invention describes a completely new approach for the detection of PML. Exosomes (small vesicles) are collected from bodily fluids such as serum. Neurally-derived exosomes are enriched using positive selection for neuronal markers. PCR can then be carried out on this specific group of exosomes to detect the presence of JCV microRNAs in the brain. This procedure is much safer than currently established systems for detecting PML, and has the potential for earlier and more accurate detection of the disorder.


  • Safe and convenient procedure
  • Earlier detection of PML


     Detection from blood, serum, or urine

Market potential/applications

Pharmaceutical companies selling monoclonal antibody therapies 

Development Stage

Proof of concept