A great-grandfather is looking forward to spending his first Father's Day with his son since receiving a life-saving kidney from him after pioneering treatment.
Jerry Sherriff, 75, from Broadstairs in Kent, had an incompatible blood group to his son Matt, 48, but surgeons at Guy's Hospital in London ensured the transplant was a success by minimising the chance of the organ being rejected.
Incompatibility affects 30% of people on the NHS Organ Donor Register, making it harder for them to have transplants.
Mr Sherriff, who also has a daughter, five grandchildren and two great-grandchildren, started to experience problems with his kidneys in 2009.
Doctors discovered they were only functioning at 30% and by 2016 this declined to 9%, but the reason was not known.
He said: "Around five years ago I was told I would eventually need to have dialysis or a transplant.
"Matt came forward and insisted on being my donor. I was reluctant to put him through the process but he insisted and I gratefully accepted his offer.
"Without him it would have taken years to get one on the waiting list and I would have needed to have dialysis. Because of my age there was also a risk that I may not have been fit enough to have a transplant in a few years' time."
After tests doctors decided the pair were a good tissue match despite Mr Sherriff being blood group O and his son being B.
In the weeks before the transplant in March 2017, Mr Sherriff had a number of plasma exchanges to lower the amount of antibodies in his blood, reducing the risk of his son's organ being rejected.
He went on: "Immediately afterwards my new kidney was functioning at 80%.
"My family were amazed to see how much better I looked. Since then I've been less tired and I'm able to play golf and do gardening again. I am so grateful to Matt and proud of what he has done for me."
Mr Sherriff Jr, a father-of-two from Malmesbury in Wiltshire, said: "When dad said he needed a transplant I knew I wanted to donate.
"I saw how his kidney problems were affecting his health and energy levels so it felt very natural to help give him back his quality of life.
"It meant I had a chance to pay him back for the things he had done for me as a kid. I had a really nice childhood and had opportunities growing up, such as memorable family holidays, which my peers didn't have."
The bank worker said he could see the difference in his father as soon as he came back to the ward after theatre.
He said: "Dad had been grey and pallid before and now he had a pink flush to his face. It felt amazing to know that was down to me. He looked 10 years younger instantly. It was also great to know I'd stopped him from needing dialysis.
"The experience has brought us and the whole family even closer as it's been a major thing for everybody. We are spending Father's Day together this year, which will feel really special considering this is the first one we have spent together since the transplant.
"I would encourage other people to donate. I think there is a misunderstanding that you have to be a perfect match. Now there are ways to overcome things that stop people donating and people aren't aware of that.
"There are also misconceptions about the donor's quality of life with one kidney. Some people think I need dialysis and others think I can't drink alcohol, but that's not the case, and you'd never know I only had one kidney by looking at me. Now I'm fitter than I've ever been and living a completely normal life."
Geoff Koffman, renal transplant surgeon at Guy's and St Thomas' NHS Foundation Trust who carried out the transplant, said: "Incompatibility affects 30% of people on the waiting list, making it harder for them to have transplants.
"At Guy's and St Thomas' we are looking at a number of techniques to overcome the problem of incompatibility so that more people can receive life-saving kidney transplants.
"In the UK around 5,000 people wait for kidney transplants every year. We have one of the biggest living donor programmes in the country, helping more people to get the transplants they desperately need."