High BMI stem-cell donors 'safe'
People with a high Body Mass Index can make equally good stem-cell donors as those who are a healthy weight, according to new research.
In the past it was thought very obese people were more likely to experience side-effects after donating, such as bone pain.
But a study of 19 people showed no evidence of side-effects.
The British Bone Marrow Registry and charity Anthony Nolan now say people with a BMI of up to 40 may donate.
Two-thirds of patients cannot find a matching donor in their family, so they rely on finding an unrelated donor through the UK bone marrow register, now called the '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 used in most stem cell donations.
The study found that the donors experienced no more side effects than people donating with a BMI of under 35.
They concluded that donating stem cell 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'.
Anthony Nolan and the British Bone Marrow Registry changed their policies around 18 months ago to allow people with a BMI of up to 40 to donate via PBSC.
Previously, both registries had not accepted donors with a BMI of 35 or above.
Dr Rachel Pawson who is presenting the research at the International Donor Registry Conference in London this weekend, 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 Annelies Billen, from Anthony Nolan said it was "encouraging" to see evidence that the method was safe for donors 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.
"We would welcome further research to improve this evidence base and will continue to monitor this group of donors in the future."
Registries in USA, Canada and Germany have relaxed their policies to allow donors with BMIs of up to 40 in recent years, and have not reported any significant problems.