VWF and systemic sclerosis: Marasini et al. [22] conducted astudy with 30 patients with systemic sclerosis, 12 patientswith PRP, and 20 healthy patients as the control group.They inspected MTHFR mutations, homocysteine, vonWillebrand factor (vWF), folate, and vitamin B12 levels.Plasma homocysteine levels were found to be higher inpatients with secondary RP than patients with primary RPand healthy controls.