Patients with potentially fatal "superbug" forms of tuberculosis (TB) could be treated using stem cells taken from their own bone marrow, according to the results of an early-stage trial of the technique. The finding, made by British and Swedish scientists, could pave the way for the development of a new treatment for the estimated 450,000 people worldwide who have multi drug-resistant (MDR) or extensively drug-resistant (XDR) TB. In a study published in The Lancet medical journal yesterday, researchers said more than half of 30 drug-resistant TB patients treated with a transfusion of their own bone marrow stem cells were cured of the disease after six months. In recent years drug-resistant strains of the disease have spread around the world and proven resistant to standard antibiotic drug treatments. The World Health Organisation (WHO) estimates that in eastern Europe, Asia and South Africa 450,000 people have MDR-TB, and half of these will fail to respond to existing treatments. TB bacteria trigger an inflammatory response in immune cells and surrounding lung tissue that can cause immune dysfunction and tissue damage. In an early trial, 30 patients with either MDR or XDR TB aged between 21 and 65 who were receiving standard TB antibiotic treatment were also given an infusion of about 10 million of their own stem cells. During six months of follow-up, the researchers found the infusion treatment was generally safe and well tolerated, with no serious side effects. Although a phase-1 trial is primarily designed only to test a treatment's safety, the scientists said further analyses of the results showed that 16 of the 30 patients treated with stem cells were deemed cured at 18 months compared with only five of 30 TB patients not treated with stem cells. Maeurer stressed that further trials with more patients and longer follow-up were needed but if future tests were successful, he said, it could become a viable extra treatment for patients with MDR-TB.