Lymphoproliferative response to membrane extracts of nasopharyngeal carcinoma

The tumor-associated antigen (TAA) was extracted from cultured cells obtained from nasopharyngeal carcinoma (NPC), and the specific immune reaction was studied by utilizing the proliferation reaction of lymphocytes from NPC patients. The following results were obtained. (1) The stimulation of lymphocytes by membrane soluble antigen (MS-Ag) was significantly different in the group of patients with NPC and the control groups (patients with malignant tumors of the head and neck and healthy individuals). Lymphocytes from the NPC patients gave a significantly higher stimulation index (SI) value with NPC MS-Ag, but a lower value with PHA, as compared with those of normal controls. (2) No definite correlation was observed in anti-Epstein-Barr virus (EBV) antibody titers. (3) As for the correlation with various histological types, apparently enhanced reaction was noted irrespective of the histological type of the cancer. (4) In connection with stage classification, the reaction was always negative in patients in stage IV. A particularly close correlation was noted between the degree of the response and the N classification. Some inhibitory factor affecting the LP reaction might appear with the progress of N and M.