There are different types of rejection, and one of the types that happens, acute rejection, is generally what we call T-cell response. We have different types of white blood cells or lymphocytes that respond, so this is the recipient’s immune system responding to the foreign tissue that is being transplanted into them. And we use strong immunosuppressive drugs, anti-rejection drugs the patient is on from the time of the transplant, and that dampens down their body’s reaction to the foreign tissue. But in the early phase, in about a quarter of all transplants you get some sort of T-cell response from the recipient responding to the foreign cells in the transplanted kidney. And we can diagnose that: we take a small biopsy of the kidney and have a look at it under the microscope. You can see these T-cells invading the kidney and we can treat that patient initially with steroid treatment and that usually reverses the rejection episode. That’s one type.

Another type is what we call an antibody response and that’s something which we’re working on really defining much more clearly than we have done in the past. That’s where the recipient produces antibodies against proteins expressed, and that requires a slightly different treatment. But the common type of acute rejection is T-cells from the recipient reacting to the foreign tissue that is the transplant.

In terms of patients coming off immunosuppressants, that is not something which we would ever recommend to our patients, but there are a small number of patients across the UK that stop themselves, stop the medication themselves. And I know that there is a team, I think in London primarily, that is looking at trying to define what it is about these patients that makes them in some way spontaneously tolerant, that they’ve stopped their drugs and they don’t reject that kidney. It is very rare, it’s a small number of patients, but trying to understand what it is about those patients would be really interesting. Very, very few of them would have donors that are identical twins, and we have undertaken one or two transplants between identical twins and we would still leave them on a very small dose of immunosuppression but I would imagine if they stopped that they would probably tolerate their transplant. But these are patients that are often recipients of deceased donor kidneys who just don’t take their tablets, in whom the vast majority would lose the kidney rapidly.

What part the mind plays in rejection: the scientist in me would say that it doesn’t, that rejection is an immunological response to an immunological injury, that you’re putting foreign tissue into somebody else and the body’s response to foreign tissue, whatever it is, is to reject it. And we try our very best, with the drugs that we treat patients with, to reduce that or dampen that down. I think the mind comes into play in terms of how individuals respond to what is dealt them. You see patients who are in really difficult circumstances who remain incredibly positive, and you’re touched and humbled by how they can be so positive, despite having kidney failure as one of a list of things that are wrong with them – but they manage to maintain a very positive outlook. My experience is that people recover quickly from a major operation like a kidney transplant if they adopt that sort of positive attitude, but in terms of rejection the scientist would have to speak out and say that I suspect that is an immunological response.