Lymphocyte cytotoxicity testing in patients and families with retinoblastoma

This study tested lymphocyte cytotoxicity from patients with retinoblastoma. Lymphocytes were tested against two permanent cell lines, WERI and Y-79. Normal volunteers served as controls. The lymphocyte reactivity of both patients with retinoblastoma and their mothers showed significant elevation compared with the controls. This strongly suggests that transplacental sensitization had occurred in utero and that the tumor was present prior to birth. Two children suspected of having retinoblastoma was tested and found to have elevated cytotoxicity titers but were later shown to have nematode inflammatory reaction. Both of their mothers' lymphocytes were not reactive to the tumor cell line. These results indicate that retinoblastoma can be present in utero with sensitization of the mother to the tumor. This test, with further refinement, may be applicable as a screening test in the differential diagnosis of retinoblastoma.