抄録
Analysis of peripheral blood lymphocytes (PBL) populations using the OK or Leu series of monoclonal antibodies is commonly conducted to investigate the immunological status of patients such as autoimmune disease, immunodeficiency syndrome, or malignant tumor. We have recently encountered two eases of osteosarcoma with deficiency of T4 epitope on helper/inducer T lymphocytes.
In case 1 with osteosarcoma of the maxilla, absence of T4 epitope in PBL was observed not only in the patient, but also in this patient's father and brother.
However, lack of T4 epitope in PBL in case 2, who harbored osteosarcoma of the mandible, was limited to the patient. Another epitope present on the helper/inducer T cells, as defined by Leu 3a antigen, was identified in 2 osteosarcoma patients and their families. Therefore, it can be considered that the lack of T4 epitope in case 1 is due to a genetic aberration with the autosomal dominant trait, and that this is due to the loss of the epitope recognized by T4 antibody and not to a lack of the helper/inducer T lymphocytes. It is known that the genes coding for helper/inducer T cell antigen and K-ras oncogene are located on chromosome 12 pter-p 12 and 12 p12. 1, respectively.
Thus, we examined the expression of ras oncogene product p 21 in PBL of osteosarcomas by immunofluorescent staining. Consequently, PBL reactive with anti-ras p 21 antibodies (Y 13-238 and Y 13-259) were clearly observed in case 2, whereas no staining was detected in case 1. These findings may imply that allelic loss of chromosome 12 pter-p 12 occurs in case 1, but not in case 2.
