Background: Systemic sclerosis (SSc) is a multisystemic disease characterized by proliferation and swelling of endothelial cells and other disorders. Raynaud's phenomenon (RP) is a disturbance, with unknown pathogenesis, that may be a precursor to SSc. The aim of this study was to investigate possible alterations in the haemostatic system and to examine whether there is a circadian variation in haemostatic variables at the initial stage of SSc.
Methods: In 20 patients with RP (in all patients secondary to SSc) and in 10 controls the levels of thrombomodulin (TM), beta-thromboglobulin (beta-TG), D-dimer (DD), tissue-type plasminogen activator (t-PA) and plasminogen activator-inhibitor (PAI-1) were measured in venous plasma samples taken at 9.00 and 14.00.
Results: Only TM levels were found to be higher in patients than in controls. Moreover the PAI-I levels, in the patient group, showed a significant circadian rhythm (with peak values at 9.00). No significant circadian variations for the other parameters were detected.
Conclusions: These data seem to indicate that in patients with RP there is an endothelial damage reflected by a significant elevation of the TM plasma level and a circadian variation in plasma PAI-1, which was higher in the morning. This observation may be an area worth exploring for its importance potential in the knowledge of Raynaud's phenomenon.