MO807: Tenascin-C is a Promising Marker of High-Turnover Bone Disease and Vascular Calcification in Prevalent Haemodialysis Patients

Abstract

Abstract BACKGROUND AND AIMS Tenascin-C is an extracellular matrix glycoprotein associated with high cell turnover, vascular calcification and atherosclerosis. This study determines the frequency of tenascin-C in uncontrolled intact parathyroid hormone (iPTH) and its relation to vascular calcification in prevalent haemodialysis patients. METHOD A cross-sectional study included 90 prevalent haemodialysis patients divided into two equal groups: uncontrolled iPTH level >300 pg/mL and controlled iPTH (150–300 pg/mL) groups. Serum tenascin-C was measured by ELISA and vascular calcification was assessed by the Adragao score, by plain X-ray on hands, pelvis and vascular access for all patients. RESULTS The prevalence of tenascin-C was 84.4% (38 patients), and vascular calcification was 46.7% (21 patients) in patients with uncontrolled iPTH. Serum tenascin-C can predict high-turnover bone disease (uncontrolled iPTH) at a cutoff value of 7377 ng/mL with AUC 0.794, sensitivity 84.4% and specificity 60%, while predict vascular calcification at a cutoff value of >8859 ng/mL AUC 0.745, sensitivity 72.7%, specificity 72.1%. Tenascin-C was high in patients with uncontrolled iPTH [median (IQR) 637 (4245) ng/mL] compared with patients with controlled iPTH [median (IQR) 211 (143) ng/mL; P-value < .0001]. According to Adragao calcification score, in uncontrolled iPTH, 31.1% (14 patients) had a score 1 and 15.6% (7 patients) had a score 2. All patients with controlled iPTH had a score 0. Patients with vascular calcification had high tenascin-C [median (IQR) 10 697 (53 974) ng/mL] compared with patients without vascular calcification [median (IQR) 7697 (18 000) ng/mL; P-value < .001]. Patients have elevated tenascin-C had 10.3, 3.7 risk to have high-turnover bone disease and vascular calcification [odds ratio (95% confidence interval) 10.3 (3–34.7), 3.7 (1.2–11.1), respectively]. Tenascin-C was positively correlated with iPTH level (r = 0.494; P < .001) in patients with uncontrolled iPTH. CONCLUSION Tenascin-C appears to be a sensitive marker for assessment of high-turnover bone disease and vascular calcification in prevalent haemodialysis patients.