Human placental growth hormone: a potential new biomarker in gestational trophoblastic disease

Objectives: Gestational trophoblastic disease (GTD) involves a spectrum of abnormal proliferations arising from the placental villous trophoblast. Although the incidence is low, a biomarker with short serum half-life would be a major clinical advance to monitor surgical and medical treatment reducing the socioeconomic burden of multiple control visits as well as patient's anxiety. Placental growth hormone (hGH-V) plays an important role in the regulation of normal placental growth and has shown angiogenic effects. We aimed to determine by immunohistochemistry (IHC) whether hGH-V is expressed in GTD and whether it can be detected in the patient's blood for potential monitoring of surgical or medical treatment procedures.

Methods: Tissue and sera were collected from women undergoing treatment for GTD in a tertiary care university hospital. We evaluated partial and complete hydatidiform moles, invasive moles and choriocarcinoma, n=16. Trophoblast specimens were examined by a newly developed IHC set-up for hGH-V in addition to gross morphologic and histopathological examination. Serum samples were analyzed by a highly sensitive hGH-V specific immunoassay.

Results: hGH-V was localized in all entities of GTD to the syncytiotrophoblast by immunohistochemistry. Serum hGH-V was detected for the first time in GTD and was present in a high percentage of all analyzed entities.

Conclusions: hGH-V can be detected in all entities of GTD by IHC as well as by serum analysis and may therefore serve as a novel biomarker for the disease. Its clinical utility in diagnosis of GTD and monitoring surgical or medical treatment needs to be determined in further studies.