A promising study has found some molecules in the blood which may help diagnose MS. This work could be used to develop a simple blood test to diagnose MS, as well as detect which type (relapsing remitting or progressive) of MS one has.

Currently, there are no definitive tests for MS, nor its progression. Diagnosis and disease monitoring relies on several parameters, including clinical examination and MRI. These tests are costly and have a limited ability to discriminate between relapsing remitting and progressive MS.

In this study, published in the highly prestigious Nature Scientific Reports, Associate Professor Buckland and his team from the University of Sydney and the Royal Prince Alfred Hospital have discovered some specific molecules called microRNAs. These microRNAs are present at different levels in exosomes in the blood of people with MS compared to those without. Additionally, they were able to use these exosomal microRNAs to distinguish between the different types of MS.

Exosomes are small particles which are shed by all cells in the body. Cells excrete them as a method of communication, often trafficking contents of cells such as microRNAs and cellular proteins.

MicroRNAs (miRNAs) are short bits of RNA, a DNA-like material which can regulate how cells use their genes. They can act as gene switches, telling cells to use or not to use various genes in the human body. So far over 1800 of these switches have been identified in humans.

MicroRNAs in exosomes are thought to be a normal part of the way cells communicate, however in inflammatory diseases, such as MS, there is an increase in the number of these exosomes shed into the blood.

During this study, the levels of miRNAs in blood exosomes of 25 people with MS (14 with relapsing remitting, 7 with secondary progressive and 4 with primary progressive) and 11 people without MS were compared. Using techniques called Next Generation Sequencing and integrative bioinformatics, the researchers sequenced the miRNAs found in the exosomes, and compared it between the different groups of people.
They found combinations of miRNAs or miRNA profiles, that could differentiate those with MS and those without, but they also could differentiate between people with progressive MS and those with relapsing remitting MS. Importantly, the scientists were able to replicate their findings in a separate group of 11 people with progressive MS, validating their results.

In a press release issued by the University of Sydney, Professor Michael Buckland is quoted as saying, “This is the first demonstration that micro-RNAs in the blood are informative biomarkers not only for the diagnosis of MS, but in predicting disease subtypes.”

These miRNAs may be able to give us great insight into the mechanism of MS, as these molecules can cross the blood brain barrier (a membrane which normally separates the circulating blood from the brain), so may have originated from the very brain cells that are under attack in MS.

But, more immediately, this work could soon be turned into a simple blood test that will allow the diagnosis of MS to be made in a more timely manner when combined with other test or clinical observations.

This may allow a more rapid diagnosis, meaning people with MS may be able to begin treatment earlier. This in turn may lead to fewer relapses and a slower loss of brain volume, resulting in better outcomes for the individual with MS.

With thanks to MS Research Australia – the lead provider of research summaries on our website.