T lymphocyte-directed gene therapy for ADA- SCID: initial trial results after 4 years.

Publication Type:

Journal Article


Science (New York, N.Y.), Volume 270, Issue 5235, p.475-80 (1995)


1995, Adenosine Deaminase, Antibody Formation, Base Sequence, Child, Child, Preschool, Female, Follow-Up Studies, gene expression, Gene Therapy, Gene Transfer Techniques, Genetic Vectors, Humans, Immunity, Cellular, Lymphocyte Count, Lymphocyte Transfusion, LYMPHOCYTES, Molecular Sequence Data, Severe Combined Immunodeficiency, T-Lymphocytes


In 1990, a clinical trial was started using retroviral-mediated transfer of the adenosine deaminase (ADA) gene into the T cells of two children with severe combined immunodeficiency (ADA- SCID). The number of blood T cells normalized as did many cellular and humoral immune responses. Gene treatment ended after 2 years, but integrated vector and ADA gene expression in T cells persisted. Although many components remain to be perfected, it is concluded here that gene therapy can be a safe and effective addition to treatment for some patients with this severe immunodeficiency disease.