Correlation between homocysteine plasma levels and nailfold videocapillaroscopic patterns in systemic sclerosis

The aim of the study is to investigate the relationship between microangiopathy as assessed by nailfold videocapillaroscopy (NVC) and plasma level of homocysteine (Hcy) in systemic sclerosis (SSc). As known, Hcy is a nonessential amino acid that interferes with normal properties of a vascular tree. Sixty patients affected by SSc (4 men and 56 women, mean age 54.6) underwent the determination of plasma Hcy level; at the same time, NVC was performed. Hcy level was also determined in 30 sex- and age-matched controls. In patients affected by SSc the plasma Hcy level was significantly higher than in healthy controls (11.8 and 6.5 mu mol/l, respectively; p < 0.001). A significant correlation was found between plasma Hcy concentration and the pattern of NVC with a progressive increase from early to active and above all to late pattern (10.7, 11.8, and 17.4 mu mol/l, respectively; p < 0.001). Subjects with high Hcy level (i.e., > 75th percentile of Hcy level in controls and in patients considered altogether) were mostly represented in the scleroderma patients with late nailfold videocapillaroscopic pattern; the crude odds ratio was 9.0 (significant; 95% CI from 2.1 to 38.8). In conclusion, Hcy plasma level is related to microvascular involvement in patients affected by SSc; the concentration increases with the progression of the nailfold videocapillaroscopic pattern. Hyperhomocysteinemia may represent an aggravating factor among the complex mechanisms involved in scleroderma damage contributing to the injury of endothelium.