Biomarkers are attractive non-invasive tools for estimating and monitoring pulmonary arterial hypertension (PAH) disease and for predicting survival in patients with PAH; therefore, many studies encouraged the investigation of new biomarkers to facilitate the diagnosis of PAH. Endostatin (ES) is an endogenous inhibitor of angiogenesis. It is produced by proteolytic cleavage of the collagen XVIII that is present in both normal and cancerous tissue. In vitro examination shows that ES can manage endothelial cells (EC) physiology in ways that could influence angiogenesis. For example, solvent ES hinders EC movement and prompts improvements of the cytoskeleton that incorporate the loss of Actin stretch strands and central grips. This effect embraces restrictions on the α5β1integrins, Tropomyosin, and putative heparan sulfate proteoglycans. Consequences for the human EC cytoskeleton include Es-induced down-regulation of Mitogen-actuated Protein Kinase (MAPK), Focal Adhesion Kinase (FAK), the Urokinase Plasminogen Activator (uPA) System, and the RhoA GTPase. Human ES has likewise been shown in a few investigations to repress EC multiplication. Moreover, ES-instigated cell cycle capture in the G1 stage is joined by Cyclin D1 down-regulation. Of note, ES blocks the proliferation and organization of endothelial cells into new blood vessels, and in animal studies, ES also inhibits angiogenesis and the growth of both primary tumors and secondary metastasis. ES was initially identified by its capacity to inhibit tumor angiogenesis in vitro and also in vivo. It can also be found in both healthy and patient’ serum, and has been detected in peripheral circulation. ES could be an attractive, non-invasive prognostic marker for some diseases, notably PAH. Therefore, the presented work is aimed at investigating the ES level in blood serum as a biomarker for detection, diagnosis and early treatment of PAH patients. In doing so, the association is ascertained between gender, age, body mass index (BMI), waist circumferences, smoking, types of PAH (primary and secondary) and this potential biomarker is assessed in PAH patients.
