Unusual molecular forms of hCG in gestational trophoblastic neoplasia.

We have observed unusual forms of human choriogonadotropin (hCG) in the urine of patients with gestational trophoblastic neoplasia. These molecules were of two types: Carboxyterminal fragments of hCG beta-subunit and desialylated forms of hCG. Substantial amounts of these materials were found in the urines of 83% and 50%, respectively, of the patients (n = 12) studied. In contrast, negligible quantities were found in the urine of 14 healthy pregnant women. Also, these unusual forms were not detectable in normal controls given an infusion of hCG. These findings indicate that these forms have clinical potential for diagnosing gestational trophoblastic neoplasia and differentiating it from normal pregnancy.