High BMI stem-cell donors 'have no side effects'

People with a high body mass index (BMI) are just as suitable for stem-cell donation as those who are at a healthy weight, according to new research.

Previously, it was thought that obese people were more likely to get side effects after donating, but a small study of 19 people has shown there were none experienced.

Stem cells are a vital part of research and the development of treatment options but transplants can be used for patients with blood cancers, such as leukaemia. The British Bone Marrow Registry and charity Anthony Nolan relaxed their policies around 18 months ago to allow people with a BMI over 40 to donate, after not enough evidence was found to support that they should not.

Around two-thirds of patients are unable to find a suitable donor within their family, so they rely on finding an unrelated donor through the UK's 'Anthony Nolan and NHS Stem Cell Registry'.

The small study, carried out by Dr Annelies Billen, medical officer at Anthony Nolan and Dr Rachel Pawson, consultant haematologist at the British Bone Marrow Registry, monitored 19 people with a BMI of over 35 for a year after they donated their stem cells.

Their stem cells were donated using a procedure called peripheral blood stem cell collection or PBSC, which is most commonly used for donation. The results show that the donors experienced no more side effects than people donating with a BMI of under 35.

They concluded that donating stem cells using this method, which is similar to giving blood, can be undertaken safely and successfully by people with a BMI of between 35 and 40 - who are classified as 'very obese'.

Presenting the research, Dr Rachel Pawson said: "This new research adds further backing for our recent policy change and indicates that it could have a positive impact on the lives of people with blood cancer in the future."

Dr Billen said it was "encouraging" to see that donation was safe for people with higher BMIs.

"This knowledge will help us save more lives as it will help us widen the pool of potential donors on our registry."