Gay and bisexual men in the UK are being urged to sign up to donate blood stem cells.

Anthony Nolan, which holds one of the largest databases of potential donors in the world, is critically short of young male donors and is keen to correct the misconception that gay men are barred from donating.

Unlike blood donation, there are no legal barriers on gay men donating blood stem cells and bone marrow. While people with HIV and other immune system problems cannot join the register, all other potential donors are screened on the basis of health and behavioural risk factors, rather than sexuality.

At any one time, around 1,600 people in the UK are in need of a transplant to treat diseases such as leukaemia and lymphoma. However, only 937 matches were found last year. Only half of those who need a transplant will ever get one.

Blood stem cell and bone marrow transplants are used as a last resort after other treatments, such as chemotherapy, have failed. Around 30 per cent of patients can find a matched donor within their family, but for the other 70 per cent, the only option is a donor from the register.

The treatment involves transplanting the stem cells found in bone marrow into a patient to help repair a damaged immune system.

Victoria Moffett, communications manager for Anthony Nolan, says there are a number of other misconceptions around donation.

One, she says, is that people assume that like with blood types, there are only a handful of different tissue types in blood stem cell transplants. In fact, there are millions of tissue types, with new ones being discovered all the time, meaning that a wide selection of donors means the best chances for ill patients.

Anthony Nolan is looking for men aged between 18 and 40 to register as donors and hopes that gay men who want to donate blood but can’t will join the register.

Victoria explains: “We’ve found that many gay men don’t know they can join our register. We want to correct that misconception.”

She says that the charity is searching for young male donors in particular because they are most likely to be selected by the consultants of sick patients. This is because they tend to be physically larger than the rest of the population, and so can give a larger donation, and are the most likely to be in good health.

The charity is keen to counter the perception that the donation process is lengthy and painful, although it is not as simple as blood donation.

In around 80 per cent of cases, PBSC (peripheral blood stem cell collection) is used. Donors are given a series of injections in the days leading up to donation – which they can receive wherever is convenient – to stimulate the production of stem cells.

On the day, donors spend around four or five hours hooked up to a blood filtering machine. A line from one arm removes blood and puts it through the machine, which extracts the parts of the blood needed for donation. The blood then returns to the body through a line in the other arm.

Victoria says patients tend to complain that the process is “boring”, rather than painful.

She says: “People say the worst is mild flu-like symptoms from the injections. But generally, they can go back to work the next day.”

The other option, which may be chosen by the patient’s consultation depending on their needs, involves a general anaesthetic, a 30-minute operation and an overnight stay in hospital.

In this case, a needle is used to extract bone marrow directly from the pelvis. Those donating through this method may need up to a week and a half off work, although most people return to work sooner.

The charity emphasises that it will reimburse donors for any time taken off work if the cost is not covered by their company. “We don’t want there to be any barriers,” Victoria says.

While the donation process is undeniably more complex than blood donation, the charity says the potential commitment is worth it.

Victoria says: “The important thing about joining the register is that you could save someone’s life. A transplant is usually the last hope of survival for someone with blood cancer for whom chemotherapy hasn’t worked.

“Young men are more likely to be asked, so we’re particularly urging them to join because they’re the group who could help us to save even more lives. Just half the people who need a transplant actually get one, so the impact that you could have on someone’s life is huge – you can’t really do more for someone than save their life.”

To find out more and join the register, visit anthonynolan.org

Olly Rofix, 25, Woodbridge, Suffolk

Olly was diagnosed with cancer (acute lymphoblastic leukaemia) in September 2005. This developed into acute myeloid leukaemia in November 2005 followed by a form of leukaemia so rare, it didn’t have a name. He had a stem cell transplant in March 2006.

He says: “The consultants weren’t sure how to treat this rare form of leukaemia, but by Christmas 2005 they decided a stem cell transplant was probably the best option. Because they weren’t 100 per cent certain they left the final decision to me. My parents were obviously very worried and concerned, but I had a rather blasé attitude towards the whole thing – I thought a stem cell transplant could only be a good thing.

“My brother was tested but he wasn’t a match for me. Then the first search on the register didn’t find a donor so there was a lot of worry about whether they’d find one at all. But I was lucky, in the end they found two possible matches. I had the transplant in March 2006, two days after my 21st birthday. It wasn’t nice but what a brilliant present.

“I was in hospital for seven weeks after the transplant and then, with the exception of an infection, recovered really well. Four years on and I can’t believe how well I’m going – since coming out of hospital, every day has been fantastically good, I feel like I’m sailing through it now.

“My donor and I had exchanged letters and Christmas cards and we met earlier this year. I was really keen to meet him. I’d absolutely no idea what to say to him though. What do you say? ‘Thank you’ sounds a little bit lame. He saved my life, I’ll never be able to repay that.

“I’d encourage everyone to join the register. To put yourself forward for the stem cell register is an absolutely incredible thing to do. Without people like my donor, people like me would be long gone.”