Immunity to antigens associated with a cell line derived from nasopharyngeal cancer (NPC) in non-Chinese NPC patients.

Delayed hypersensibility to antigens derived from four lymphoid cell lines was measured in 27 non-Chinese patients with nasopharyngeal cancer (NPC) and 63 non-NPC cancer patients. Of the NPC patients, 17/27 (63%) had a positive skin test response to antigens derived from HKLY-28, a lymphoid cell line which was developed from an NPC biopsy. Only 10/51 (20%) and 1/13 (8%) patients with solid tumors and hematopoietic malignancies, respectively, had positive skin test responses to HKLY-28. Positive skin tests were found less frequently when extracts from cell lines derived from normal individuals or lymphoma patients were utilized, although NPC patients were more reactive to two of the non-NPC derived cell lines than the controls. The NPC patients in this study also had significantly elevated antibody titers to the Epstein-Barr virus (EBV), capsid antigen (VCA) and early antigen (EA). Titers were highest in the patients with more anaplastic nasopharyngeal carcinomas. The skin test and serologic data are consistent with studies in Chinese patients, indicating that NPC in non-Chinese and Chinese patients is biologically similar.