Detection of early pregnancy factor-like activity in women with gestational trophoblastic tumors.

The presence of immunosuppressive early pregnancy factor (EPF) in the maternal serum has so far been associated with gestation. Its presence in the serum of women with gestational trophoblastic tumors was investigated. The results indicate that while EPF activity was detected in the serum of women with choriocarcinoma, no such activity was detected in the serum of women with hydatidiform mole, leading to the novel use of EPF as a marker to distinguish these two clinical situations. Results of the experiments also suggest that EPF moiety present in the maternal serum during pregnancy may be of different molecular entity than that present in the serum of women with choriocarcinoma.