A FOLATE BINDING-PROTEIN IN ASCITIC FLUID, SERUM AND OVARIAN TISSUE OF PATIENTS WITH OVARIAN ADENOCARCINOMA IMMUNOREACTS WITH ANTIBODIES AGAINST HUMAN-MILK FOLATE BINDING-PROTEIN

The presence of a folate binding protein which immunoreacts with antib odies against human milk folate binding protein was demonstrated in as citic fluids from seven patients with ovarian adenocarcinoma. Ascitic fluids collected from two patients with other malignancies contained n on-immunoreactive FBP. Tumor tissue specimens from five patients with ovarian carcinoma contained immunoreactive FBP. By contrast to normal ovaries ovarian carcinoma tissue showed positive immunostaining on imm unohistochemistry. Ascitic fluids from two patients with ovarian carci noma exhibited single distinct bands on SDS-PAGE immunoblotting. The g el filtration profile of ovarian carcinoma tissue homogenate from two patients contained 25 and 100 kDa peaks of radioligand-bound and immun oreactive folate binding protein, while ascitic fluid from one of the patients exhibited a large 100 kDa immunoreactive peak with no radioli gand binding activity. The immunoreactive non-functional 100 kDa FBP c ould represent unprocessed precursor FBP. Future studies are necessary to evaluate whether determination of immunoreactive FBP in ovarian ad enocarcinomatosis is of any diagnostic value.