Effect of local radiotherapy on the level of EBV-associated membrane-reactive antibodies in the sera of patients with certain malignant tumors

The effect of radiotherapy on antibodies to EBV-induced membrane antigens (MA) was studied in 6 patients with Burkitt's lymphoma (BL), 16 with nasopharyngeal carcinoma (NPC), and 18 controls receiving radiotherapy for other malignant tumors. The tests were performed on sera taken shortly before radiotherapy, about 2 months after radiotherapy, and, in some cases of nasopharyngeal carcinoma and Burkitt's lymphoma, 4–20 months after radiotherapy as well. About 2 months after radiotherapy, there was an increase in anti-MA antibody levels in the BL group and in the NPC group as well. This increase persisted in the group of NPC patients followed during a longer time after radiotherapy. With one exception, a maxillary carcinoma, there was no increase in the control group. Possible implications of these findings are discussed.