Monocyte chemoattractant protein‐1 and CC‐chemokine receptor‐2 in severe hypercholesterolaemia

Abstract

Objectives: To investigate whether plasma concentrations of monocyte chemoattractant protein‐1 (MCP‐1) and the gene expression of its receptor on the monocyte cell surface CCR‐2 were elevated above normal in subjects with asymptomatic, isolated hypercholesterolaemia and if statin treatment could influence this cytokine. Methods: The investigation was designed as a cross sectional study followed by a single, blind, treatment study of patients receiving pravastatin 80 mg/day for 8 weeks. The study included 23 patients with severe hypercholesterolaemia (LDL>5.2 mmol/L) and 39 normocholesterolaemic controls. Blood samples were obtained from patients and controls at baseline and from patients at end of the study and analysed for lipoproteins and inflammatory mediators: MCP‐1, high‐sensitivity C‐reactive protein (HS‐CRP). Isolated peripheral mononuclear cells were analysed for CCR‐2 gene expression. Results: Mean plasma LDL‐C was significantly higher in patients than in controls. No difference in plasma MCP‐1 levels or CCR‐2 gene expression was seen between the groups at baseline, nor were there any differences in plasma concentrations of CRP. After treatment with pravastatin, LDL‐C decreased by 31%. Treatment did not significantly affect the levels of MCP‐1 or CCR‐2 gene expression, nor was CRP affected by treatment with pravastatin. Conclusions: Our study does not support the view that MCP‐1 plasma levels and CCR‐2 gene expression in circulating monocytes are directly responsible for the monocyte recruitment into the arterial intima in patients with severe asymptomatic hypercholesterolaemia. In addition, the inflammatory response of a high concentration of LDL‐C in isolated asymptomatic hypercholesterolaemia is minute.

• CC‐chemokine receptor‐2
• C‐reactive protein
• hypercholesterolaemia
• inflammation
• monocyte chemoattractant protein‐1
• pravastatin