[Analysis of tumor antigens and clinical applications of monoclonal antibody (A 2 B 5) for neuroblastoma].

Monoclonal antibody (A 2 B 5) was raised against chick neural retina cells by Eisenbarth et al. We have studied, exclusively, A 2 B 5 for the immunological approach, and the following results were obtained. A 2 B 5 was shown to be IgG 2a subclass and reacted with all human neuroblastoma cell lines, NBGOTO, NB 1, TN-1 and C-NB1, in vitro by the 51Cr release cytotoxicity assay, but did not have cytotoxic activity for other tumor cell lines, C-1300 (A/J mouse neuroblastoma cell line), S1509a (A/J mouse induced sarcoma by methylcholanthrene) and P 39 (human malignant melanoma cell line). A 2 B 5 was titrated against constant numbers of human neuroblastoma cell lines. In the next experiment, detection of metastatic neuroblastoma cells in bone marrow, specimen and human neuroblastoma cell lines was undertaken by indirect immunofluorescence using A 2 B 5. All were visualized with binding A 2 B 5, and immunofluorescence could be seen on a clump of tumor cells binding A 2 B 5. Thus, A 2 B 5 may be particularly useful reagent for the diagnosis of bone metastasis of human neuroblastoma.