Gene therapy progress

Genetic therapy is becoming a realistic treatment for a number of disorders. At the meeting of the American Society for Haematology in New Orleans, advances in gene therapy for two disorders were reported. These were X-linked severe combined immunodeficiency (SCID) and haemophilia B. In SCID, affected individuals have virtually no T lymphocytes or natural killer (NK) cells and the only treatment is bone-marrow transplantation. Marina Cavazzana-Calvo (Hopital Necker, Paris) reported that in the two patients with the longest follow-up, T lymphocytes and NK cells were increased to normal numbers and normal T-lymphocyte function achieved. Although the results are preliminary, this may represent the first cure of a genetic disease by gene therapy. Researchers also reported in last week's issue of Circulation the successful use of gene therapy to revive failing heart cells. So far, the therapy has worked only in hearts that have been removed from the patients. The researchers report that getting the gene to take in a living body still needs more work. The team, which includes Dr Sian Harding of Imperial College London, based the trials on the gene SERCA2a which instructs cells to produce a protein that is involved in controlling heart muscle contraction. In this particular trial, the cells from the failing hearts began beating and contracting at almost normal levels.