But they share a unique bond and Margaret Jackson would not be living the life she is today if Maureen Jack hadn’t donated one of her kidneys.
Ten years ago, the 72-year-old from St Andrews in Fife became one of the first people in Scotland to part with an organ to save the life of a complete stranger.
She made an altruistic, non-directed donation and later formed a real life bond with her ‘kidney twin’ which is highly unusual under the circumstances because most donors and recipients have little or no contact.
Mrs Jack described the operation as a “minor inconvenience” but it was an act that made a “huge difference” to Mrs Jackson.
The women decided to share their story to celebrate World Kidney Day which is being marked at the Scottish Parliament tomorrow.
Mrs Jackson, 67, said: “I would be dead now if I hadn’t had a kidney transplant because I was in desperate need.
“What Maureen did was amazing and she has given me my life back.
“I was in hospital for three months and I was lucky enough to be the best match for her kidney out of a waiting list of 8,000 people.
“She has done me a very good deed and I’ll be forever grateful.”
Most people have two kidneys and only need one to live a normal, healthy life.
Mrs Jack, an elder at St Leonard’s Parish Church in St Andrews, is a supporter of the Give a Kidney Scotland charity and said she hopes more people would become altruistic organ donors.
In Scotland there are currently around 500 people on the kidney transplant waiting list and in the last 10 years 264 people have died waiting for an operation.
Mrs Jack was 62 when she donated in 2009 and said that she has never regretted her decision to do so.
But she admitted that the reaction among her friends was mixed.
Mrs Jack, a member of the Church of Scotland’s World Mission Council, said she had a very personal reason for donating one of her kidneys.
World Kidney Day falls on the anniversary of the death of her husband George 20 years ago.
Mrs Jack said: “He died from a non-kidney related problem and I would have done anything to give him his life back.
“So being able to do that for someone else has been important to me.
“I first became aware of the possibility of donating a kidney to a stranger after hearing about it on the radio.
“I visited someone in hospital who, along with very serious lasting consequences of an infection, was on dialysis.
“I remember her joy that her kidneys had regenerated and so she was able to come off dialysis.
“I remember thinking that I would have been happy to give her a kidney and then realising that I would also be happy to donate a kidney to someone I didn’t know.”
Mrs Jack said the Church and Society Council of the Church of Scotland has supported the campaign for people to register as organ donors.
“However, relatively few of us will die in such a way that it is possible for our organs to be used after our death,” she added.
“After we had spoken about my experience, a retired GP, a Quaker, joined me in becoming an altruistic kidney donor.
“It would be terrific if some folk in the Church would also consider this kind of giving.”
Mrs Jack underwent a nephrectomy at the Royal Infirmary of Edinburgh and said the post-operation pain was minimal and within a week she was walking up to a mile.
“It was no more than a minor inconvenience for me, but it has made a huge difference to Margaret,” she added.
“It’s good to know that ‘our’ kidney is still going strong.”
Mrs Jackson, who lives in Cumbria, and Mrs Jack met for the first time in Edinburgh four years ago.
They met at Mrs Jackson’s request after some years of contact, initially anonymously through their hospitals and then exchanging Christmas cards.
Give a Kidney Scotland said it costs around £25,000 for a donor operation on the NHS and an average of £30,000 a year to keep someone on dialysis.
The average period on dialysis before a transplant is four years which means there are very significant cost savings to the NHS.
Altruistic kidney donation is one of two routes to being a donor, with directed donations also being made to a person’s friend, relative or partner rather than a stranger.
Chris Jones, chairman of Give a Kidney Scotland, said the charity’s mission is to raise awareness of altruistic kidney donation to try and save lives.
The Edinburgh man, who is a kidney donor himself, said: “The 78 people who have so far donated a kidney to a stranger in Scotland over the last 10 years have undoubtedly helped to save the lives of their recipients.
“Around 8 out of 10 of the population are unaware that they can donate one of their kidneys to a stranger and many of the population are unaware that while most of us have two healthy kidneys, we only need one to live a healthy life.
“Our ambitious aim is to make Scotland the first country where no-one need die for the want of a kidney.”
Mr Jones said that while it is a major operation, the recovery time is quite quick and the aftercare is thorough and superb.
“This kind of kidney transplant also provides one of the best ways to give recipients a chance of securing the best match to their needs,” he added.
“And in many cases it opens the door to allow further transplants to take place by creating a ‘chain’ of donors.”