[Gene therapy for adenosine deaminase deficiency].

Severe combined immunodeficiency (SCID) due to adenosine deaminase (ADA) deficiency is a fatal recessive disorder caused by mutations in the gene encoding ADA. Based on the first clinical trial of two young girls with ADA-deficient SCID by recombinant retrovirus-mediated gene transfer at the National Institute of Health of USA, we prepared to treat a four-year-old boy with ADA-deficient SCID who had been treated with PEG-ADA for 3 years. Approval to perform the clinical trial of gene therapy by using his peripheral blood T lymphocytes as the target and recombinant retroviral vector (LASN) as the vector for ADA gene transfer was obtained from both of the Ministry of Health and Welfare and the Ministry of Education, Science, Sports and Culture on 13 February, 1995. The first clinical trial of gene therapy for the patient was initiated on 1 August 1995. He received 8 x 10(8) LASN-transduced lymphocytes in an injection administered intravenously on 8 August and 2.5 x 10(9) transduced lymphocytes on 4 September without any side reactions. The procedure, safety and efficacy of clinical trial of gene therapy were discussed.