Homocysteine concentration in primary and systemic sclerosis associated Raynaud's phenomenon

Objective. To investigate whether patients with systemic sclerosis (SSc) ha ve raised homocysteine (Hcy) plasma levels, thought to be an independent ri sk factor for vascular disease, and to study the relationship between Hcy a nd endothelial damage, and between Hcy and methylene-tetrahydrofolate reduc tase (MTHFR) genotypes, and patients' vitamin nutritional status, which are among the more frequent causes of hyperhomocysteinemia. Methods. We measured Hcy, von Willebrand factor (vWF), folic acid, and vita min B12 plasma levels and analyzed the frequencies of MTHFR mutations in 30 patients with SSc and 12 patients with primary Raynaud's phenomenon (RP); 29 healthy subjects served as controls. Results. Patients with SSc had higher Hcy and vWF concentrations than those with RP (p < 0.01 and p < 0.02, respectively) or controls (p < 0.02 and p < 0.0001, respectively). Folic acid and vitamin B12 were lower in SSc than in RP (p < 0.01 and p < 0.02, respectively) or controls (p < 0.05). MTHFR g enotype did not influence Hcy, folate, or vitamin B12 concentrations, but p atients homozygous for the mutant gene had higher vWF levels. Conclusion. Patients with SSc, but not those with RP, had significantly hig her Hcy and vWF plasma levels. Nutritional rather than inherited factors se em to have a pathogenic role in SSc hyperhomocysteinemia.