A monoclonal antibody (FMG25) that can differentiate neuroblastoma from other small round-cell tumours of childhood.

The monoclonal antibody (MAb), FMG25, raised following immunization of mice with the human T cell line HUT 78, binds to human neuroblastoma but not to other small round-cell tumours of childhood (rhabdomyosarcoma and Ewing's sarcoma). The specificity of the reagent is paralleled on normal tissues binding to brain but not frozen sections of thymus, tonsil, lymph node and spleen. Of the 15 T-cell malignancies examined, only 3, belonging to the large T-cell type, were positive. This represents only 50% of this type examined. Only one early case of pre-B ALL was found to be positive for FMG25 binding out of 27 non-T-cell malignancies. The pattern of reactivity of FMG25 makes the MAb useful as a diagnostic reagent in paediatric pathology. In addition, the antibody may be useful as one of a panel of reagents applied to detect and remove tumour cells from bone marrow harvested for autologous transplantation.