IT’S possibly one of the most touching scenes you’ll see in a TV documentary this year.

It takes place in a Glasgow hospital. John Monaghan has just been given one of his wife Caroline’s kidneys. The operation has gone very well.

“I think I’ve just been given the best Christmas and anniversary present ever,” says John, shortly afterwards. “I can’t wait to see her, just to give her a big hug.”

We then see John being wheeled in his bed to his wife’s room. Like her, she is wearing a hospital gown. Not surprisingly, she looks exhausted by her ordeal.

“I feel terrible,” she says. John apologises for having put her through all of this, but tells her that his new kidney started working immediately.

“That’s a good thing, John,” says Caroline. “I think I would have battered you if it hadn’t have worked.”

His words edged with emotion, he expresses his gratitude to her, and reaches out to clasp her hand.

The scene can be watched next Monday night in the second and final part of BBC Scotland’s Transplant Tales.

The documentary makers were given full access to Scotland’s Transplant Service at a time when there is a massive shortage of kidneys, livers, lungs and hearts for transplant.

More than 20 years ago, John, who works as a taxi driver, was diagnosed with Henoch-Schönlein purpura (HSP), which can cause chronic kidney disorder in adults.

Two years ago, he was told by doctors that if he did not get a new kidney, he would need dialysis three times a week to survive.

For the last five weeks before his transplant, John actually underwent regular dialysis, but the documentary says it has side-effects that could have killed him.

Dr Marc Clancy, transplant surgeon, says: "We have lots of patients who are having terrible problems maintaining safe dialysis, and they are really quite often in danger of dying. We desperately need to give those patients a kidney."

A transplant became so important for John.

Caroline, 51, a mum of two who works as a primary-school teaching assistant, had volunteered to donate one of her own kidneys, but she was at first told by the doctors that her blood type was incompatible with John’s.

It meant that John’s antibodies - his body’s natural defence system - would attack and destroy it.

This was a substantial problem, but the medical world got round it by a method known as ABO Incompatible Kidney Transplantation.

“We have a protocol by which we give drugs to reduce the level of antibodies in John’s bloodstream, such that on the day of the transplant, those are at really low, minimised levels, and the transplant can proceed without any harm from the antibodies,” Dr Clancy says. It was this “window of opportunity” that allowed the operation to go ahead, at Glasgow’s Western Infirmary, late last year.

An indication of how new the method is comes from Mr John Asher, consultant transplant surgeon, who says in the documentary: “Literally, only a few years ago, we would have said this wasn’t possible.”

John has recently been recovering from a bout of pneumonia unrelated to his transplant.

“He had PCP, which is a pneumonia that can kill you - you either end up in intensive care, or you don’t make it at all,” said Caroline.

“For some reason, even though John doesn’t have an immune system anymore, because of the drugs he takes to stop his kidney from rejection, he has actually come through it. He’s back to normal.”

Caroline herself was off work for five months after her operation. “They had told me I might be off for anything up to 16 weeks, but John was back to work after six weeks.”

She laughs. “I think I’m still recovering and everything is hunky-dory with John.

“Sometimes when they do a kidney transplant, you can get what they call a ‘sleepy’ kidney - it’s sleeping, which means that it hasn’t started working yet.

“But John’s new kidney started working as soon as it was hooked up to his bladder and everything. They hadn’t even stitched him up, apparently, when it was working a treat.

“He’s got a better kidney function now than I do! He’s even got the best function of anyone in the clinic, apparently, and he’s on less medication, as well.

“But they’re just amazed, because it’s an incompatible transplant - they haven’t been doing these for very long. Only for a couple of years, it seems. That just makes it even more special, I suppose.”

Last year, before his operation, John took Caroline to New York for her 50th birthday. “He saved up for it,” she says. “We’ve never done anything like that before. His kidney function had deteriorated badly.

“It was fantastic, an absolutely amazing place,” Caroline says of New York. “We normally go for beach holidays where we can chill, but, oh my goodness - we were up at six o’clock and didn’t come back to the hotel until seven at night! We never stopped.”

John, meanwhile, has been returning to the golf course to indulge one of his favourite hobbies.

“He just wants things to be normal and I have to understand that,” says Caroline. “I want to wrap him up in cotton wool, saying you can’t do this, you can’t do that, but he knows his own body.”

In the documentary, John, 52, acknowledges his very personal debt to Caroline.

“It’s a great thing she’s doing,” he says with feeling, some time before the operation. “I’ll be paying it back for the rest of my life.”

* Transplant Tales, BBC One Scotland, Monday July 6, 9pm

• The Organ Donation Scotland campaign is urging people who have made the positive decision to be an organ donor to talk it through with their family.

• Sharing organ donation wishes remains fundamental to relatives honouring a loved one’s choices in the event of their death.

• Since 2010/11, the family authorisation rate for organ donation – when a family member agrees that donation can proceed - has increased from 57.1 per cent to 61.6 per cent. If the rate was to further increase to 80 per cent, around 90 more lives could be saved each year.

• Even if someone has joined the NHS Organ Donor Register, it’s important they tell those close to them that they’ve made the decision to be an organ donor.

• Scotland has made huge progress in organ donation and transplantation, with a 62 per cent increase in transplants since 2007/8 and 41 per cent of Scots now on the NHS Organ Donor Register.

• Saying the seven words ‘I’d like to be an organ donor’ can save up to seven lives.

• Organs that can be transplanted are; kidneys, heart, lungs, liver, pancreas, small bowel.

•In Scotland, around 550 people are currently waiting for a transplant that will give them a second chance at life.

• Three people in the UK die every day waiting on a transplant.

• To find out more about organ donation and to join the NHS Organ Donor Register, visit organdonationscotland.org