Trophoblastic disease monitoring: Evaluation of pregnancy-specific beta 1-glycoprotein.

Pregnancy-specific beta 1-glycoprotein (SP1) was evaluated as a potential marker protein for monitoring trophoblastic disease. Four patients with post-molar pregnancy accompanied by spontaneous titer remission and three patients with nonmetastatic trophoblastic disease were found to have regression curves for both human chorionic gonadotropin (hCG) and SP, which closely followed each other. Of three patients with metastatic choriocarcinoma, two were shown to have discordant hCG and SP1 patterns, SP1 in both cases was plateauing or rising while hCG continued to fall. Two other patients are described, one with a spontaneous remission, and one who previously had had choriocarcinoma and was found to have low levels of hCG with higher levels of SP1.