Leukocyte Migration Inhibition in Patients With Ewing's Sarcoma by 3-m Potassium Chloride Extracts of Fresh and Tissue-Cultured Ewing's Sarcomas

Leukocyte migration inhibition (LMI) assays were performed to detect cell-mediated immune reactions against tumor-associated antigens (TAA) of Ewing's sarcoma. With the use of crude antigen preparations obtained by 3 m KCI extractions of fresh Ewing's sarcoma or of tissue culture cells derived from a pleural effusion of a Ewing's sarcoma patient, assays were performed with leukocytes from these patients, patients with other cancers, and normal donors. The results demonstrated approximately 60% or greater positive LMI reactivity in Ewing's sarcoma patients, as compared to less than 10% reactivity of normal donors, with the use of extracts of either fresh or tissue-cultured Ewing's sarcoma cells. A lower proportion of positive reactivity was observed in patients with breast and lung cancer. Further specificity tests indicated that a smaller proportion of patients with Ewing's sarcoma had LMI reactivity with KCI extracts of tissue-cultured cells derived from breast cancer or fresh lung cancer celts than did patients with the homologous disease. The results indicate that many patients with Ewing's sarcoma have cell-mediated immunity toward TAA on Ewing's sarcomas. Inasmuch as all the LMI assays were performed with allogeneic extracts, the data also suggested that different Ewing's sarcomas possess common antigens and that some breast and lung cancers may share some TAA with Ewing's sarcoma.