Endothelin‐1 serum levels correlate with MCP‐1 but not with homocysteine plasma concentration in patients with systemic sclerosis

Abstract

Objectives: To determine whether homocysteine (Hcy) plasma levels are correlated with molecules indicative of endothelial cell and fibroblast activation, including endothelin‐1 (ET‐1) and monocyte chemoattractant protein‐1 and ‐3 (MCP‐1, MCP‐3), in patients with systemic sclerosis (SSc).

Methods: Eighty‐two patients were enrolled in this study; the control group included 75 age‐ and sex‐matched subjects. Plasma Hcy was determined by high‐performance liquid chromatography; folic acid, and vitamin B₁₂ plasma levels were determined by a chemiluminescence method. ET‐1, MCP‐1, and MCP‐3 were determined by enzyme‐linked immunosorbent assay (ELISA). Analysis of the 677C→T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene was performed by polymerase chain reaction (PCR) and digestion with the enzyme HinfI.

Results: Hcy levels were lower in patients whereas ET‐1 was significantly higher in patients and correlated with MCP‐1. Stratification of the patients on the basis of Hcy levels was not associated with any statistical difference in the concentration of ET‐1, MCP‐1, and MCP‐3. Patients with diffuse disease presented the highest levels of ET‐1 and MCP‐1. The distribution of the MTHFR genotypes was not different in patients and controls.

Conclusions: In SSc, Hcy plasma concentration does not influence ET‐1, MCP‐1, or MCP‐3 levels. On the contrary, ET‐1, a marker of vascular activation, correlates with MCP‐1, a chemokine involved in the fibrotic process of SSc.