Potential to improve treatment for juvenile dermatomyositis thanks to new research

7 Feb 2023, 11:33 a.m.

Image showing mitochondria from a patient with JDM

Research, supported in part by GOSH Charity, has looked at how the DNA of those with juvenile dermatomyositis (JDM) differs to those without it.

The teams behind the research have uncovered key inflammation pathways involved in JDM, and used an existing drugN-acetyl cysteine (NAC)to reverse the inflammation in cells.

The findings from this new research will allow researchers to look for "new and very specific drugs" to improve the treatment of the condition and improve care. 

JDM is a rare autoimmune condition in children. It's where the body’s immune system attacks muscles and skin, leading to muscle weakness and skin rashes.

Treatments used in JDM suppress this overactive defence system. However, they do not work for all patients and can cause unwanted side effects, further worsening a severe condition.

If the exact part of the body’s defence system causing these problems was known, researchers could better target the condition with more effective medications.

New research, led by Dr Merry Wilkinson at University College London Great Ormond Street Institute of Child Health (UCL GOS ICH) and published in Annals of Rheumatic diseases, has studied the DNA of children with JDM (patients from GOSH and 16 centres across the UK). It set out to see which genes are switched on and off in immune cells called monocytes.

The key findings from Dr Merry Wilkinson’s research

Dr Merry Wilkinson and her team found that the genes responsible for mitochondria (the ‘powerhouse’ energy producers of the cell) were less active in children and young people with JDM – even those already on strong treatment – when compared to children without JDM.

Mitochondria contain their own DNA, called mitochondrial DNA, which is different to the DNA found in the nucleus (control centre of the cell). By comparing patient samples, Dr Merry Wilkinson and her team also found that mitochondria from patients with JDM were more varied in size and there was more mitochondrial DNA leaked out of the mitochondria into the main part of the cell compared to mitochondria from children without.

The mitochondrial DNA from children and young people with JDM was also found to be ‘oxidised’ and this can switch on genes that lead to inflammation. However, the team found that these genes could be switched off in immune cells, by blocking the oxidation pathways and by using an existing anti-oxidant drug called N-acetyl cysteine (NAC).

Image of Dr Merry Wilkinson next to quote  “We believe these discoveries will allow us to look for new and very specific drugs to improve the treatment of Juvenile Dermatomyositis … "

A “great need” for more targeted treatments

Dr Wilkinson said: “Juvenile Dermatomyositis is thankfully a very rare childhood autoimmune disease but there is a great need for more targeted treatments as it’s poorly understood.

“We believe these discoveries will allow us to look for new and very specific drugs to improve the treatment of Juvenile Dermatomyositis and provide better care for those living with the condition.

“We are extremely privileged to work on the Juvenile Dermatomyositis Cohort and Biobank study, one of the largest databases of both clinical and biological JDM samples in the world, and very grateful to all the patients and families who donate samples to research like ours.

“This study is a great example of clinical and research teams coming together as we couldn’t develop our findings and help patients without clinical teams supporting recruitment, sample and clinical data collection.”

Find out more by visiting the GOSH website.

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