title: Evaluation of haemostatic parameters and circadian variations of the haemostatic system in patients with systemic sclerosis and Raynaud's phenomenon.
abstract: 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.
authors.affiliation: Department of Internal Medicine, University of Messina, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Trifiletti
authors.forename: S
authors.initials: S
authors.lastname: Bartolone
authors.forename: R
authors.initials: R
authors.lastname: Scamardi
authors.forename: M A
authors.initials: MA
authors.lastname: Pizzoleo
authors.forename: G
authors.initials: G
authors.lastname: Sottilotta
authors.forename: D
authors.initials: D
authors.lastname: Larosa
authors.forename: N
authors.initials: N
authors.lastname: Barbera
mesh_terms: D000368:Aged; D002940:Circadian Rhythm; D005260:Female; D006487:Hemostasis; D006801:Humans; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011928:Raynaud Disease / Q000097:blood*; D012595:Scleroderma, Systemic / Q000097:blood*; D018180:Thrombomodulin / Q000097:blood
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D018180:Thrombomodulin