Siglec-1 on monocytes is a potential risk marker for monitoring disease severity in coronary artery disease

Objectives: Siglec-1 has long been considered as an important biomarker of the activation of monocyte/macrophage and a type 1 interferon-specific imprint, but its role in atherosclerosis has not been elucidated. Methods: We examined the expression of Siglec-1 by flow cytometry and RT-PCR in 83 CAD patients and 38 healthy controls. In addition, the levels of serum lipids, Gensini score, hs-CRP and homocysteine were determined. Results: The transcriptional and protein levels of Siglec-1 on monocytes in CAD patients were significantly increased compared with healthy controls [3.17 versus 1.0, P < 0.01; (11.5 +/- 3.9)% versus (1.8 +/- 2.0)%, P < 0.01], but the increased Siglec-1 had no correlation with the level of native serum lipids. Interestingly, the expression of Siglec-1 was positively correlated with Gensini score (r=0.338, P=0.015), hs-CRP (r=0.316, P=0.016) and homocysteine level (r=0.224, P=0.042). Conclusion: Siglec-1 may be considered as a potential non-invasive indicator for monitoring disease severity and a biomarker for predicting the relative risk of cardiovascular events. (c) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.