Doctors can more accurately predict which liver patients have the greatest chance of their organ regenerating naturally after the development of a technique looking for tiny molecules in blood, according to research.
The work, by a team from King’s College Hospital in London, looked at levels of certain tiny molecules in the blood of patients with acute liver failure. It will allow organ transplants to be freed up for those most in need.
The researchers found that high levels of the molecules were a better predictor of recovery from liver failure than the tools used in the NHS at present. The molecules are a type of microRNA, present in all cells. They play a role in regulating gene expression, or how much of its protein a particular gene makes at a particular time.
Dr Varuna Aluvihare, consultant hepatologist at King’s College Hospital and author of the study, said: “We have identified that a novel microRNA-based prognostic model outperforms standard prognostic models in paracetamol-induced acute liver failure. These findings take us a step forward in rapidly identifying the most appropriate course of treatment.”
He said that for some patients, acute failure could result in critical illness and the need for life-saving liver transplantation. But he added: “Other patients, with similar levels of liver damage, recover without the need for surgical interventions. This is all down to the regenerative powers of the liver.”
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The benefits of better identifying which patients fall into which category were twofold, he said. “We don’t want to transplant people who don’t need a transplant because this is one of the biggest operations in any setting. You're then tied to taking anti-rejection pills and regular follow-up and all kinds of bumps along the road, albeit that we have very good outcomes from transplantation. So number one, for the patient, if they don’t need a transplant that will be a better outcome.
“And the second thing is, of course, [that] organs remain scarce. We still have people who desperately need a transplant on our waiting list who die every year because they don’t get an organ. So, if you can save any of these organs from being utilised unnecessarily that would be a very good thing.”
According to NHS Blood and Transplant, the average wait for a liver transplant from a deceased donor in the UK is between three and four months. Patients in acute liver failure have only days to find a match.
The Institute of Liver Studies at the hospital published a list of early indications of poor prognosis in patients with acute liver failure in 1989. Known as the King’s College Criteria, it is widely used internationally and looks at the level of damage to the liver using markers such as levels of bilirubin in the blood, clotting, and altered mental status. The new technique is different because rather than looking at how damaged the liver is, it considers how well it may be able to regenerate and recover.
Although the study was based on samples from 196 living and dead patients in North America who had liver failure after a paracetamol overdose, the findings were likely to apply to other causes of liver failure, the researchers said.
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Aluvihare said they would seek to validate their findings in other patient populations, and work with an industrial partner to make the test something easily used in any hospital. He hopes it could be ready for use in about two years. The research was published yesterday in the Journal of Hepatology.
There were 942 liver transplants carried out in the UK in the financial year 2019-20. Most were from deceased donors, with 19 from living donors.
