Mr Sherwin, 53, of Hugh Street, Castleford, was visited this week by Emily Luckhaupt, 50, from Germany, who received his bone marrow 15 years ago to successfully battle against leukaemia.
The operation was the mum-of-one's last chance to live and has resulted in a special bond between the donor and recipient.


Emily, or Emi as she is known, her husband Gerhard and son Lutz, 18, travelled to Castleford this week for the pair's fourth meeting.
Mr Sherwin said: "This is the first time Emi has been to Castleford since I moved here from my previous home in Aylesbury.


"The first time we met, when I went to Germany in 2004, was nerve-wracking and quite emotional. Emi couldn't stop crying and was at my side almost all the time.
"All the people I met over there had given a blood test to be a donor for Emi, but none were a match.
"Because of that, I now have the most wonderful extension to my family and the constant feeling that I helped a husband love his wife for longer and a son grow with the love of his mother."


Mr Sherwin signed up to the bone marrow register during the 1980s and in 1993 was told he was a match for a 33-year-old German mum.
Mr Sherwin said: "In Germany, you aren't allowed any contact with your donor for ten years and in 2003 I was told that Emi wanted to get in touch. We wrote to each other for a while before we met the following year."


He urged people to sign up and help save lives of people waiting for bone marrow.
He said: "I see it as an extension to giving blood. Yes, there's a risk with the anaesthetic just like every operation but for me I just went to sleep and had an aching back, like I had been gardening.


"That was the only discomfort, and that was all it was – discomfort.
"I would urge anyone to get registered. The chance of becoming a match is slim but the more people who are registered, the better chance the people who need a transplant have of getting one.


"I don't think there's anything better than helping a stranger. It's usual to help your family, or someone you know, but to help a stranger is fantastic.
"I would do it again in a flash if someone needed my bone marrow."