In the News
Research Focus: The "DeFat" study
A recent BBC news story caught my attention: Man given months to live becomes liver transplant pioneer
The article describes how a 58-year-old man with liver cirrhosis and non-alcoholic fatty liver disease expected he would not live more than a few months, when he was given the opportunity of a liver transplant. However, this was not 'just' a liver transplant, but part of a clinical trial.
What is the DeFat trial?
We would like to assess whether a new technique for removing fat from a liver can improve the safe and successful use of livers that are ordinarily offered for transplant but are retrieved from donors at risk of having a fatty liver. The objective of this study is to make fatty livers safe for transplantation and thereby increase the number of transplants that can be safely conducted.
There is a strict criteria for selection of both donor livers and patients to this trial. In patients, this includes things like age, type of liver disease and so on. As this a randomised clinical trial, what this means is that those taking part will receive a donor liver from either the control group (fat not removed from the liver) or the test group (fat removed from the liver). In fact, this is a double blind trial, which means that neither the surgeon performing the transplant, or the patient receiving the transplant, knows whether the donor liver is from the control or the test group.
Randomisation and blinding are important in studies that want to explore the effectiveness of treatments. They are methods that reduce bias and improve the reliability of research.
- The selection criteria means that everyone taking part in the trial has a similar type of disease, so the effects of the treatment are being tested on a similar group (reducing the variables)
- Every trial participant has an equal chance of being randomised to either the control group or the test group, so the test group genuinely represents the population under study
- Having a control group and a test group means you can be more sure that any difference in the treatment group is not happening by chance but because of the intervention
- Double blinding means that the researchers will not introduce any bias when setting up the trial and the doctors and patients will be more objective when assessing and reporting outcomes
- For example, researchers could unintentionally choose to put the healthier patients in the treatment group to improve results
- For example, doctors might unintentionally overstate the improvements in patients in the treatment group
- For example, the patients might also overstate how well they feel if they know they have received the test treatment
It is important to remember that in this trial, all participants are receiving a treatment. Liver transplant is the only treatment for end-stage liver disease. What is being tested, is whether donor livers that are pre-treated prior to transplant result in better outcomes. It is not known whether the 'defatting' of donor livers will offer any benefit - this is one of the things being tested.
What outcomes will the study measure?
The main purpose of the study is to see if using this defatting technique can increase the number of donor livers available to transplant. Therefore, the researchers will be tracking the success and safety of the transplant itself, as well as the ongoing health of the transplanted liver and the patient receiving the transplant. This will be done through blood testing, imaging (scans) and patient assessments.
Participants will be followed up for 6 months after their transplant. One-year post-transplant follow-up data will be obtained from the NHSBT (NHS Blood and Transplant) registry.
Why is this research important?
Liver transplantation is the only successful treatment for end-stage liver disease but is limited by a shortage of suitable donor organs. Unfortunately, a third of donated livers cannot be used for transplants, often due to the presence of fat within the liver cells.
Here are two excellent videos to help you understand:
- Randomised control trials
- Non-alcohol related fatty liver disease