Plasma kisspeptin is raised in patients with gestational trophoblastic neoplasia and falls during treatment

1 Department of Metabolic Medicine, Hammersmith Hospital; and 2 Department of Medical Oncology, Charing Cross Hospital, Imperial College London, London, United Kingdom Submitted 14 November 2005 ; accepted in final form 1 June 2006 Kisspeptin is a 54-amino acid peptide, encoded by the anti-metastasis gene KiSS-1 , that activates G protein-coupled receptor 54 (GPR54). The kisspeptin-GPR54 system is critical to normal reproductive development. KiSS-1 gene expression is increased in the human placenta in normal and molar pregnancies. Circulating kisspeptin is dramatically increased in normal pregnancy, but levels in GTN have not previously been reported. The present study was designed to determine whether plasma kisspeptin levels are altered in patients with malignant GTN. Thirty-nine blood samples were taken from 11 patients with malignant GTN at presentation during and after chemotherapy. Blood was also sampled from nonpregnant and pregnant volunteers. Plasma kisspeptin IR and hCG concentrations were measured. Plasma kisspeptin IR concentration in nonpregnant ( n = 16) females was