ES cell therapies must be safe, say scientists

Appropriate safety systems must be in place before embryo stem cell therapies are used to treat patients, according to an editorial published in the British Medical Journal (BMJ) last week. The article says that although many more human embryonic stem cell (ES) lines are now available, much more work needs to be done to ensure the safety and effectiveness of such cells before they can be used therapeutically. The authors also flagged up a forthcoming debate to be held in London next week, entitled 'Stem Cell Research: Hope or Hype?' (See Recommends).

The article, written by stem cell scientist Stephen Minger, IVF expert Peter Braude and haematologist Ruth Warwick, coincided with the news that a Korean team has created 11 new cell-lines derived from cloned human embryos. But, say the authors, no stem cells have yet been grown in the conditions that would be expected for any pharmaceutical product to be used clinically. They cite the 'premature' application of gene therapy, the devastation caused by HIV (human immunodeficiency virus) transmission to people with haemophilia, hepatitis C infection through blood transfusions and the transmission of bovine spongiform encephalopathy from cows to humans as 'learning opportunities' for stem cell researchers.

Many scientists hope that research on human ES cells will eventually lead to new therapies for a range of diseases. However, the BMJ article points out that a single stem cell line could potentially be used for hundreds or even thousands of patients, which would amplify the potential risk of disease transmission from a single donor. It goes on to say that the forthcoming European Union (EU) directive on tissues and cells will go some way to addressing these concerns. The directive, which comes into effect in April 2006, will set stringent quality standards covering all labs carrying out IVF or therapeutic stem cell research.

The authors conclude that 'stem cell research needs to be nurtured safely and methodically to provide real benefit to patients in the future. Cambridge stem cell expert Roger Pederson told the BBC News website he was confident that stem cell research in the UK was safe, although he was concerned about some research taking place elsewhere. 'The rule of thumb here is that if anyone is asked to pay to take part in a trial, then they probably should not do it', he said, adding 'any legitimate trials will be paid for by governmental sources'.