Objectives: To investigate the expression of monocyte chemoattractant protein-1 (MCP-1) and CC chemokine receptor-2 (CCR-2) in circulating monocytes in patients with stable (SAP) and acute coronary syndrome (ACS), and relate the findings to circulating levels of MCP-1 and other inflammatory biomarkers.
Methods: The study included 40 patients each with stable CAD and unstable CAD, and a control group of 50 age- and sex-matched healthy persons. Whole blood was taken and sera were analyzed for MCP-1, IL-6, sVCAM-1, siCAM-1 and P-selectin using ELISA and CRP was analysed by Tina-quant CRP high sensitive assay. Monocytes were isolated from whole blood and were analyzed for CCR-2 and MCP-1 gene expression using realtime RT-PCR.
Results: No significant differences in gene expression of MCP-1 or CCR-2 were seen between the groups. Neither were any differences in circulating levels of MCP-1-seen. Serum levels of sVCAM-1, siCAM-1 and sP-selectin did not differ between the groups. Mean CRP levels were elevated in the ACS group compared to controls and SAP. Patients with SAP had lower levels compared to controls, probably reflecting the extensive use of statins in this group (96 %). IL-6 was significantly higher in ACS compared to controls and SAP. Positive correlations were seen between MCP-1 vs. sVCAM-1 and sICAM-1.
Conclusions: Neither patients with SAP nor ACS had different MCP-1 or CCR-2 gene expression compared to controls. The serum levels of MCP-1 did not differ between the groups. In this study, we can not see circulating MCP-1 or CCR-2 gene expression in monocytes as useful clinical tools to decide the severity of CAD in this population.