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

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.

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.

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.

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.