Researchers are reporting "extraordinary" results using our body's T-cells to combat leukaemia. The therapy works by engineering the body's own immune cells to attack cancerous cells. Not only are the cancerous cells destroyed, they are also - according to early clinical trials - stopped from returning. The new therapy has had unprecedented results in early trials on several patients who typically would have only months to live. Some of these patients showed complete remission after 18 months of follow-up checks. In one study of 35 patients with acute lymphoblastic leukaemia, 94% went into remission, although there was a possibility that symptoms could reappear. Details of the clinical trials were discussed at the American Association for the Advancement of Science at their annual meeting in Washington DC. Chiara Bonini is one of the researchers particularly hopeful about the new results, having never seen the same rates of remission in the last 15 years of trials. She said: "this is really a revolution." T-cells are vital to the body's immune defences, helping defend against viruses and bacteria. They can also keep a "memory" of previous infections, this allows the body to rapidly defend against repeat infections. However, T-cell therapy is still regarded as a last resort for most patients due to the possibility of severe side effects. Of the patients who took part in the clinical trials, twenty suffered from Cytokine release syndrome, a common complication with the use of T-cell infusions. These patients suffered from fever, neurotoxicity and hypotension. Two patients also died during the course of the trials. Researchers noted, however, that chemotherapy had failed all of these patients. A paper containing the full research is currently under review and will be published later this year.