Radial artery calcification in end-stage renal disease patients is associated with deposition of osteopontin and diminished expression of α-smooth muscle actin

Aim: Vascular access is the lifeline of haemodialysis patients and radial‐cephalic fistula is the preferred type of access. We investigated vascular calcification in uraemia radial arteries and compared it with clinical parameters. Methods: Artery specimens from 30 end‐stage renal disease patients were collected, examined calcification by von Kossa and Alizarin red staining. Expression of α‐smooth muscle actin (α‐SMA) and the main component of bone matrix, osteopontin (OP) were detected by immunohistochemistry. Results: In uraemia vessels, calcification was mainly located in the medial layer. Nineteen (63.33%) patients had no evidence of calcification, six (20%) had mild/moderate calcification and five (16.66%) had severe calcification. Upregulation of OP and diminished expression of α‐SMA occurred in the medial layer, especially in the area of severe calcification. The calcification score, decreased expression of α‐SMA and upregulation of OP were positively correlated with older age, serum calcium, serum phosphorus and calcium × phosphorus product (P