The Development of an Enzyme Immunoassay for Placental Tissue Protein 17 (PP17) and Its Clinical Significance

We developed an enzyme immunoassay (EIA) for placental protein 17 (PP17) using avidin biotin binding, and measured the serum-PP17 levels of 37 healthy men, 103 nonpregnant women, 48 pregnant women, and 86 patients with gynecologic malignancies. The mean level was 12.8 ng/m/ in healthy men and 44.2 ng/m/ in nonpregnant women (p<.05). The calculated upper limit of normal was 97.8 ng/m/ (mean + 2σ). The serum PP17 concentration was remarkedly reduced postmenopausally. Pregnant women showed a mean serum level of 19.2 ng/m/, which was significantly lower than that of nonpregnant women. Immunoserological results strongly suggest that PP17 is produced far more in the normal endometrium than in the placentae and decidua. Patients with gynecologic malignancies had obviously lower mean serum PP17 levels (8.3 —19.9 ng/m/) than those found in healthy nonpregnant women. Measurement of the serum PP17 concentration might be useful in distinguishing gynecologic malignancies from various normal conditions.