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

Authors


Dr Xiaoyun Wang, Division of Nephrology, Department of Internal Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China. E-mail: nn_wang22@hotmail.com.

SUMMARY:

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 < 0.01).

Conclusion:  Vascular calcification in uraemia radial arteries is mainly located in the media layer. The risk factors appear to be older age, an elevated serum level of phosphorus, calcium and calcium × phosphorus product.

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