抄録
Based upon the knowledges of experimental studies on leukemic mice, the specific immunotherapy was applied in children with acute lymphoblastic leukemia.
The analytical studies of leukemic cells indicated that the tumor associated specific antigen was present and it was suggested to be common to leukemic cells of different patients.
Since 1975, 67 children have been registered and treated under three different protocols, and 47 children treated under protocol 7501 (23 children), and protocol 7611 (24 children) were evaluable.
As active specific immunotherapy, 1-4×108 irradiated leukemic cells were monthly injected intracutaneosly, and BCG (Product of Japan BCG Company) was given at the site of immunization by multiple puncture method, as children were induced to complete remission.
The maintenance chemotherapy was continued for 3 years, and immunotherapy for 5 years.
By October 1979, 15 of 23 children (65.2%) under protocol 7501 were in the 1st continued remission with mean duration of 32.2 months, and 16 of 24 children (66.7%) under protocol 7611, with mean duration of 23.8 months.
Although it was too early to induce any conclusions, the late relapse, especially in bone marrow, seemed less frequent.
When yearly relapse was observed, 12 of 47 children (25.5%) had relapsed during the 1st 2 years, 4 of 29 children (13.8%) after 2 years, and 1 of 11 children (9.1%) after 3 years.
Among 6 relapsers, after 2 years of the 1st continued remission, only one developed bone marrow relapse, and others in CNS or testis.
For the immunologic parameters, delayed type of skin reaction, in vitro blastogenic response assay, lymphocyte cytotoxicity assay, and humoral antibodies were carried out along with the course of chemoimmunotherapy, and it was found that these parameters correlated with the clinical status of children to some extents. The skin test was thought most practical. The ultimate clinical evalution of these therapeutic studies should be awaited for another few years, but rational basis for applying immunotherapy is abundant for childhood ALL.
The prevention from the occurrence of late relapse will be the matter of calling attention.
