Growth Arrest-specific 6 Protein and Matrix Gla Protein in Hemodialysis Patients

Introduction. Plasma protein growth arrest-specific 6 (GAS6) and matrix Gla protein (MGP) are crucial mediators of vascular calcification and are involved in the development of vascular complications in chronic kidney diseases. This study was set out to investigate the relationship between plasma GAS6 levels and MGP in patients with end-stage renal disease on maintenance hemodialysis. Materials and Methods. Forty-six hemodialysis and 46 healthy individuals with normal kidneys were recruited. Plasma GAS6 and MGP concentrations and related biochemical factors were quantified as well as collection of data on clinical characteristics. Results. Plasma GAS6 levels were significantly higher in the hemodialysis patients as compared with the control group (763.52 ± 187.91 pg/mL versus 421.63 ± 189.91 pg/mL, P < .001). Plasma MGP concentration was significantly lower in the hemodialysis patients than the control group (52.35 ± 12.35 ng/ mL versus 6.60 ± 19.54 ng/mL, P < .001). The levels of GAS6 were inversely associated with MGP (r = -0.341, P = .02) in the hemodialysis patients. Conclusions. Increased GAS6 and decreased MGP levels in hemodialysis patients, as mediators of induction or prevention of vascular calcification, and their inverse correlation may suggest that there might be a role in increased calcification process in hemodialysis patients or only as a secondary phenomenon of advanced kidney failure. Their direct role on vascular calcification needs further studies in the future.