Specific antigen stimulated lymphocyte proliferation in osteosarcoma.

A lymphocyte proliferation assay (LPA) for cellular immune responses to osteosarcoma antigens is described and applied to an examination of peripheral blood lymphocytes (PBL) taken from osteosarcoma patients. The antigen preparations were derived from 3 M KC1 solubilized osteosarcoma, taken from a limited number of patients. Lymphocytes from most tumor-bearing patients were stimulated to significant proliferation when cultured in normal human serum. Such stimulation was observed whether or not the lymphoid cells were preincubated 24 hours at 37 degrees C prior to addition of antigen. Patients whose lesion had been resected and who were without evidence of disease for 5-70 months had diminished proliferative responses. Lymphocytes from normal subjects, from patients having other types of sarcoma, and patients having carcinomas rarely responded to the soluble osteosarcoma antigens. When responsive PBL taken from tumor-bearing patients were cultured in autologous serum, the proliferative responses were abrogated or blocked. Serial assays made in the course of bearing this tumor under a variety of therapeutic regimens, including an immunotherapy protocol, suggest that the LPA may be useful in monitoring clinical progress of the disease and possibly in other immunotherapy protocols for osteosarcoma.