[HLA antigens in choriocarcinoma].

Choriocarcinoma can be regarded as transplanted cancer, because its origin is in trophoblast which is fetal tissue. It is of interest whether HLA antigens are expressed on choriocarcinoma cells or not, since HLA antigens may play an important role if the patient's body could recognize choriocarcinoma as "not self" and initiate its immune response. In this report choriocarcinoma tissue in the uterus, obtained after hysterectomy, is stained by an indirect immunofluorescence technique using monoclonal antibodies to HLA-A,B,C and HLA-DR. We believe this is the first immunohistological study in which choriocarcinoma in utero is available for study and monoclonal antibodies to HLA antigens are applied. In the staining of HLA-A,B,C, and of HLA-DR, host cells, such as myometrial cells, show positive staining but choriocarcinoma cells show negative staining. It is thought that choriocarcinoma cells are viable and show negative staining of HLA antigens, on the basis of finding following HE staining and hCG staining using anti-hCG antibody and the clinical remarks of the patient such as her high urinary hCG titer before operation and no history of chemotherapy. These results agree with those of previous studies about HLA antigens on choriocarcinoma cell lines.