Search

Increasing evidence suggests that levels of angiogenic proteins within blood platelets change at the earliest stages of cancer development and may thus provide a promising diagnostic and prognostic tool. Patients with cirrhosis have increased risk of developing hepatocellular carcinoma (HCC). We aimed to study whether development of HCC in hepatitis-related cirrhosis results in changes in platelet levels of angiogenic proteins. We studied the intraplatelet levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF), endostatin, platelet factor 4 (PF4) and thrombospondin type 1 (TSP-1) in 38 consecutive patients with hepatitis B- or C-related liver cirrhosis with or without HCC in addition to plasma levels of the same proteins. Twenty healthy volunteers were included to establish reference values for the various tests. Intraplatelet levels of VEGF, bFGF, HGF and endostatin were significantly higher in patients compared to controls. Intraplatelet levels of PDGF, PF4 and TSP-1 were comparable between patients and controls. Plasma levels of VEGF, bFGF and endostatin were comparable between patients and controls. Plasma levels of PDGF, PF4 and TSP-1 were decreased in patients, but this difference disappeared when levels were corrected for platelet count. Intraplatelet and plasma levels of all proteins assessed were comparable between patients with and without HCC. In conclusion, the intraplatelet levels of some angiogenic proteins are elevated in cirrhosis, but do not discriminate between patients with and without HCC. Thus, intraplatelet levels of angiogenic proteins do not seem useful as diagnostic or prognostic biomarker of HCC in cirrhotic patients. [ABSTRACT FROM PUBLISHER]

Background and Aim: Blood platelets have been shown to stimulate liver regeneration after partial hepatectomy in animal models and humans, but the molecular mechanisms involved are unclear. It has been proposed that growth factors and angiogenic molecules stored within platelets drive platelet-mediated liver regeneration, but little direct evidence in support of this mechanism is available. Methods: We assessed levels of relevant platelet-derived proteins (vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, platelet-derived growth factor, thrombospondin, and endostatin) in platelet-rich and platelet-poor plasma taken at various perioperative time points from patients undergoing a (extended) right partial hepatectomy ( n = 17) or a pylorus-preserving pancreatico-duodenectomy ( n = 10). In addition, we collected intraoperative samples from the efferent and afferent liver veins prior to and after completion of liver resection. Twenty-four healthy controls were included to establish reference ranges for the various tests. Results and Conclusions: Although we demonstrate perioperative changes in platelet and plasma levels of the proteins assessed, the changes observed in patients undergoing partial hepatectomy largely mirror the changes observed in patients undergoing a pylorus-preserving pancreatico-duodenectomy. In addition, no change in the growth factor levels in platelet-rich plasma between afferent and efferent liver veins was observed. Thus, the absence of an intra- or postoperative consumption of platelet-derived proteins in patients undergoing partial hepatectomy argues against a role of release of these molecules in stimulation of liver regeneration. Relevance for patients: In depth knowledge of the mechanism underlying platelet-mediated liver regeneration may facilitate development of targeted therapeutic interventions for patients with failing liver regeneration, which for example may occur following a partial hepatectomy. Although the prevailing dogma is that platelet stimulate liver regeneration by release of growth factors stored within platelets, data in this manuscript argue against this mechanism and suggest other pathways to be responsible., Competing Interests: The authors declare no conflict of interest.