Elevated sera levels of SP-1 induced by chemotherapy in patients with metastatic gestational trophoblastic diseases

6 patients with invasive mole and 5 patients with choriocarcinoma were treated from 1983 till 1986. Serum samples were analyzed by simultaneous determining of pregnancy-specific beta-1-glycoprotein (SP-1) using enzyme-linked immunosorbent assay (ELISA) and beta subunit of human chorionic gonadotropin (beta-hCG) using Serono radioimmunoassay kit. In 2 patients with metastatic gestational trophoblastic disease (MGTD) SP-1 peaks were found during chemotherapy. In patients with MGTD with normalized beta-hCG levels a repeated, temporary elevation of isolated SP-1 levels was observed within some months following chemotherapy. After the last isolated peak of SP-1 the pulmonary metastases disappeared. This phenomenon was interpreted as a consequence of the oncolytic process in the affected tissue. In 1 patient with nonmetastatic choriocarcinoma SP-1 ELISA pseudoreaction was found. To recognize these pseudoreactions, a control plate with nonimmunized rabbit IgG was used, simultaneously with SP-1 determinations.