A 12-year-old boy who received a kidney from a stranger has met the man who transformed his life.
Tom Higgs is the first person at Great Ormond Street Hospital in London to receive a kidney from an altruistic living donor.
Most living donors are family members but, on occasion, strangers will offer up their kidneys to help save other people's lives.
Tom met his donor, Roger Sutton, a 53-year-old GP from Portsmouth, after the pair exchanged letters through their transplant co-ordinators.
Tom has suffered from a rare type of kidney disease, atypical haemolytic uraemic syndrome (HUS), since the age of five. It causes kidney failure together high blood pressure.
The schoolboy, from Ruislip in Greater London, needed dialysis every single night for five years. He was put on the waiting list for a donor following somebody's death when he was eight.
A family donor was not possible and Tom knew that a kidney from an altruistic living donor was his best option.
Tom's mum Vicky said: "Those years on dialysis were very stressful and restrictive on our lives.
"We knew that he was really poorly and would eventually need a transplant. I had to set up the dialysis machine and get Tom on it by 7pm each evening so he would be off it in time to get ready for school the next morning.
"I needed to change his dressings before attaching him to the machine and also had to give him weekly injections. It was heartbreaking knowing how much Tom disliked all of this, but we had no choice as his kidneys weren't working and we had to filter his blood."
Donors and recipients normally remain anonymous but Tom and Mr Sutton decided to waive that right to highlight the benefits of organ donation.
Tom underwent the surgery in 2011 and met Mr Sutton this year.
His mum said: "Our lives have changed so much, it's hard to believe.
"Before the transplant, we had to wait for Tom to come off the machine so we could get together and open our presents around the Christmas tree.
"On his birthdays, we usually brought his presents up to his room. Christmas is so different now, and Tom is definitely looking forward to the celebrations this year.
"When we heard about the match, we were told that the organ was from a living donor who had decided to donate a kidney to a stranger. We were really surprised that someone would be so selfless."
Mr Sutton underwent the operation at Queen Alexandra Hospital, Portsmouth during a planned sabbatical from his GP work.
He said: "I can't pinpoint the exact moment when the idea to donate a kidney first came to me. I suppose what started out as a thought grew into a quiet conviction that it was the right thing to do - a chance to say thank you for all the great things that have happened in my life.
"Looking back, I can see there's been a bit of a 'renal thread' running through my life.
"My grandmother lived for 35 years after having one of her kidneys removed. I watched a kidney transplant operation when I was a medical student. Twenty years ago a friend of mine had a transplant after developing renal failure.
"My wife Debbie, who is a dietician, was for many years part of a renal dietetics team. As a GP, I have seen just how important organ donation is and how many lives have been saved through transplants."
Mr Sutton underwent a rigorous assessment before the operation, both mentally and physically. He was also tested to ensure his remaining kidney would function well.
Dr Stephen Marks, a consultant kidney specialist who leads the kidney transplant programme at Great Ormond Street, said: "We are delighted with Tom's progress since his transplant. Each year up to 36 of our patients undergo kidney transplants but Tom was the first one in our hospital to receive a kidney from a healthy member of the public who was also a complete stranger.
"The numbers of children, young people and adults on the transplant waiting list far outweigh the number of organs that are available for transplant.
"It can sometimes be difficult to find a suitable donor among living relatives and there simply are not enough people on the organ donor register willing to donate after their deaths.
"Altruistic non-directed kidney donation from individuals who are prepared to selflessly undergo a major operation opens up another vital source of organs."
Mr Sutton's consultant surgeon, Sam Dutta, said: "The number of altruistic kidney donations has been on the increase here in Portsmouth over the last few years. Since the start of this type of donation in 2007, we have seen 31 altruistic donations. This is one of the most selfless acts a person can do and we know that a healthy person can live a perfectly normal life with one good kidney.
"In 2012, Portsmouth contributed the largest number of altruistic kidneys in the country."
Figures released in May showed that the number of living people giving one of their organs to a stranger almost tripled in one year in the UK.
The Human Tissue Authority approved 104 altruistic organ donations in 2012-13 compared with 38 the previous year.