Children who need bone marrow transplants, such as those with genetic immune system disorders, could benefit from a new technique that reduces the need for chemotherapy. The new technique uses antibodies rather than chemotherapy to clear a patient's own bone marrow prior to transplant of donor marrow. Doctors from Great Ormond Street Hospital and UCL's Institute of Child Health reported their findings in The Lancet last week.

Chemotherapy used to clear a patient's bone marrow prior to transplant can have toxic side effects, for example it can damage the lungs and liver. Some babies and children are too sick to receive the high doses of chemotherapy needed to wipe out bone marrow.

The new antibody therapy was given to children with primary immune deficiencies (PID) who were too ill to receive chemotherapy. PID are a group of genetic disorders where children are vulnerable to infection and frequently have chronic illness. A bone marrow transplant is often the only option for treating PID.

The antibody specifically recognises and destroys cells of the blood and bone marrow, without damaging surrounding tissue. Thirteen of the 16 children at Great Ormond Street Hospital who received the treatment survived and are now cured of their conditions. There were some complications, but the patients recovered in half the time taken by those given the standard treatment.

The team hope that the technique can be developed to help other children who need a bone marrow transplant, but much more research is needed.

Dr Persis Amrolia, who led the study, said 'Because this approach was experimental, we only used it on the sickest children, who we felt could not tolerate standard transplant chemotherapy.

'Given how sick these children were before transplant, the results are remarkable.

'What's really encouraging is that pretty much all the children who survived now have a really good quality of life.

'There's still a lot to do and the challenge now is to develop similar targeted approaches for children with other genetic diseases and leukaemia'.