I mentioned in my previous post that I had been asked to take part in a small study investigating how it may be possible to induce tolerance in liver transplant patients. I thought it might be interesting to share my experience of participating in this clinical trial.
It was explained to me that our immune system comprises cells called lymphocytes. There are different types of lymphocytes, and immunosuppression medication weakens all of them equally to prevent rejection.
Researchers have found that as well as making cells that damage the transplanted organ, our immune system also makes cells that suppress rejection. It is a particular type of lymphocyte called a ‘Regulatory T Cell’, that actually has a positive effect in inducing tolerance of the transplanted liver. I am told this has been shown to be effective in mice.
It is believed that these regulatory cells may be able to suppress rejection in liver transplant patients, and if so induce tolerance and allow patients to wean down their immunosuppression medication.
Clearly, for me, there is no guarantee of anything here because this is just a study, but if it is found to be effective the benefits for future transplant patients could be very significant.
The process involves detailed tests. I have already given over 20 tubes of blood, urine sample, and will have to undergo a liver biopsy to ensure there is no sub-clinical rejection before the trial process goes ahead. My Tacrolimus immunosuppression has been reduced and supplemented with Sirolimus.
Assuming the biopsy is fine (fingers crossed, as I really hate having them done), I will go through a process called leukapheresis. This involves lines being inserted and my blood being filtered through a machine to harvest a quantity of white blood cells, with the remaining blood being returned to my blood stream from the machine. I believe about four litres go through the machine.
From these white blood cells, the regulatory cells are isolated, purified, and expanded in a laboratory to increase the number by several orders of magnitude. At a later time these expanded cells will be re-introduced to my system using a regular infusion device.
A few days after the treatment, I will need to give blood samples six or seven times to analyse how well my immune system and the regulatory cells are working.
This study takes about a year to complete. Now I have typed all this out I really do feel like a guinea pig, or one of those poor laboratory mice.
It is early days, and I have to get past the biopsy next, but I will update with progress and let you know how this goes, if people are interested to hear.