Researchers say they have found a link in the pathology between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
The work is being carried out by professor Sonya Marshall-Gradisnik and the team at Griffith University's National Centre for Neuroimmunology and Emerging Diseases (NCNED).
"It is the first of its kind in the world to actually biologically identify the overlap in the dysfunction with long COVID and ME/CFS patients," she said.
Dr Marshall-Gradisnik said damaged receptors, like a dysfunctional lock and key, do not allow enough calcium in.
"The receptors are located on every cell in the body," she said.
"These ion channels, or the lock and the key that tries to open the door — when we look at ME/CFS patients, that's been significantly impaired.
"When we looked at the same receptor [in long COVID patients], we're now reporting the same change."
The findings will be published in the Journal of Molecular Medicine.
Fast-tracking research and treatments
Dr Marshall-Gradisnik and the team at NCNED have studied chronic fatigue for the past decade, but pivoted to long COVID after they noticed similarities between the two illnesses.
Australia has recorded more than 9.5 million cases of COVID-19 since the start of the pandemic.
Dr Marshall-Gradisnik said about five per cent of those had long COVID.
"It may be a public health priority and it has significant implications for the healthcare system long-term," she said.
She said the focus was now on developing a high throughput test, which she hoped to see widely available.
"We've identified these receptors and we've introduced into the laboratory certain drugs that are well known, have incredible safety data and they target these receptors," Dr Marshall-Gradisnik said.
"We understand the pathology of ME/CFS and, given this overlap with long COVID, where this positions us is now to fast-track our research and implement further treatments over a period of time."
'Sent me way back'
Kathy Dallest was first diagnosed with ME/CFS more than 20 years ago and said she had experienced a relapse in conditions since she had COVID-19 in April.
"That has sent me way back — I'm still suffering from that," she said.
She said the symptoms felt the same.
"I'm really quite debilitated again, exhausted with any movement," Ms Dallest said.
"I'm breathless walking not very far away and it's the exhaustion, pain and sleep issues."
Ms Dallest, an active member of ME/CFS support groups, said she had noticed people with long COVID starting to reach out for support.
She said the findings and the possibility of treatment for long COVID offered hope to sufferers.
"Especially to younger people, who know that their future, in a sense, has been lost," she said.
Research must continue: AMA
Australian Medical Association (AMA) Queensland president Maria Boulton, a GP who treats people with long COVID and ME/CFS, said the research could make a real difference to people's lives, but that the findings would have to be independently verified.
"We know that both illnesses affect patients to the point where some of them have daily symptoms and some of them can't go to work," she said.
"It's really important that research such as this continues to be done.
"Normally what happens with research is there is a process where the data will be looked at and it will be independently verified, of course, to ensure that it's all what it's meant to be.
"It's important to allow that process to continue."
Dr Boulton said Australia's medical and health research was not as well funded as it was in the US and the UK.
"We are lobbying for more funding to go into research because it is essential that we stay ahead of the curve," she said.
She said AMA Queensland had been calling on the state government for more research into long COVID.
"We knew that it was going to be an issue that affected Queenslanders when the borders opened last year," she said.
"At the moment there's no real guidelines for us GPs to follow when we're helping our patients with long COVID."
