Serum asporin levels in maintenance hemodialysis patients without osteoarthritis

Abstract

Aims: Several human and experimental studies have shown that small leucine-rich proteoglycans might play a significant role in inflammation and fibrosis in various renal diseases. However, as far as we know, no study has reported asporin levels in patients with advanced renal disease. The primary aim of this study was to determine serum asporin levels in hemodialysis (HD) patients without symptomatic osteoarthritis. Methods: This single-center, cross-sectional study prospectively enrolled maintenance HD patients and healthy control subjects. Subjects with clinically clear osteoarthritis were excluded. Serum asporin level was measured via Human ASPN (Asporin) ELISA Kit (Elabscience Biotechnology Inc. Houston, Texas, USA) in fasting blood samples. Results: The study included 25 (mean age: 43.3±13.5 years, 60% were females) patients and 29 control subjects (mean age: 38.0±8.8 years, 37.9% were females). Patients and controls were similar in age and sex. Serum asporin levels were significantly higher in HD patients compared with the controls 2.4 (0.9-4.8) ng/mL vs. 0.3 (0.2-0.6) ng/mL, respectively, p<0.001). Asporin levels were not correlated with age (r=0.344, p=0.092) and the duration of HD (r=0.385, p=0.077). Among HD patients, asporin level was not significantly correlated with C-reactive protein, parathyroid hormone, calcium, or phosphorus levels. Conclusions: This study showed that serum asporin levels were significantly elevated in patients undergoing HD. Further studies must elucidate the possible origins of increased asporin in these patients.