USA hCG reference service, 10-year report.

INTRODUCTION: The USA hCG Reference Service has been dealing with cases of persistent low levels of hCG and gestational trophoblastic diseases for 10years. Here we present the complete experience. METHODS: Total hCG in serum and urine was measured using the Siemen's Immulite 1000 assay. Hyperglycosylated hCG, nicked hCG, free ss-subunit and ss-core fragment were measured using microtiterplate assays with antibodies B152, B151, FBT11 and B210, respectively. RESULTS: The USA hCG Reference Service has identified 83 cases of false-positive hCG, 71 cases of aggressive gestational trophoblastic disease (GTD), 52 cases of minimally invasive GTD, 168 cases of quiescent GTD and 22 cases of placenta site trophoblastic tumor (PSTT). In addition, 103 cases of pituitary hCG have been identified, 60 cases of nontrophoblastic tumor, 4 cases of inherited hCG and 2 cases of Munchausen's syndrome. This is 565 cases total. Multiple new methods are described and tested for diagnosing all of these disorders. CONCLUSIONS: The USA hCG Reference Service experience shows new methods for detecting multiple hCG-related disorders and recommends new approaches for detecting these hCG-related disorders.

Following metastatic placental site trophoblastic tumor with urine beta-core fragment.

OBJECTIVE: We document a case with metastatic placental site trophoblastic tumor in a 47-year-old postmenopausal women. METHODS: beta-core fragment was measured in urine using the Triton UGP kit. hCG was also measured using the Bayer Immuno-1hCG assay (at Memorial Sloan-Kettering Cancer Center). RESULTS: Over 2 years the patient underwent two courses of chemotherapy and two debulking operations. During this time, hCG levels decreased from 227 to 4.1 mIU/ml. hCG levels were close to the limit of detection (<3 mIU/ml), indicating complete or near-complete regression of disease. At this point urine beta-core fragment levels were determined. High levels were detected 7.9 fmol/ml, consistent with the continued existence of tumor (>1.9 fmol/ml). High-dose chemotherapy (CEM) was started with stem cell harvesting. In the following weeks hCG levels failed to identify the tumor (4.1 to <3 mIU/ml). In the first week (during therapy) beta-core fragment levels increased (12 fmol/ml), and in the following weeks (after therapy) levels regressed to 1.2 fmol/ml. CONCLUSION: Urine beta-core fragment may be a useful tumor maker when serum hCG levels are near to or below the limit of detection.