title: Activation of the tissue factor pathway of blood coagulation in patients with chronic urticaria.
abstract: BACKGROUND
  In patients with chronic urticaria (CU), plasma shows signs of thrombin generation and autologous plasma skin tests score positive in as many as 95% of cases.
  
  
  OBJECTIVE
  To evaluate the initiators of blood coagulation that lead to thrombin generation and fibrinolysis in CU.
  
  
  METHODS
  Activated factor VII, activated factor XII, fragment F(1+2), and D-dimer plasma levels were measured in 37 patients with CU and 37 controls. Skin specimens from 10 patients with CU and 10 controls were tested for tissue factor immunohistochemically.
  
  
  RESULTS
  Mean F(1+2) levels were higher in patients than controls (2.54 [SD 2.57] nmol/L vs 0.87 [0.26] nmol/L; P < .001); disease activity was moderate or severe in 9 of 11 (82%) and 9 of 26 (35%) patients showing high or normal F(1+2) levels, respectively (P < .025). Mean D-dimer plasma levels were higher in patients than controls (329 [188] ng/mL vs 236 [81] ng/mL; P < .01); disease activity was moderate or severe in 6 of 8 (75%) and 11 of 29 (38%) showing elevated or normal plasma D-dimer levels (P = NS). Factor VIIa levels were higher in patients than controls (2.86 ng/mL [0.66] vs 1.97 ng/mL [0.65]; P < .001). Activated factor VII and F(1+2) levels were correlated (r = 0.529; P = .008). Tissue factor reactivity was observed only in CU skin specimens.
  
  
  CONCLUSIONS
  The extrinsic pathway of clotting cascade is activated in CU. Disease severity is associated with the activation of the coagulation cascade.
  
  
  CONCLUSIONS
  The involvement of the coagulation pathway in CU opens new perspectives for a better understanding of the pathogenesis and, possibly, for the treatment of this disease.
authors.affiliation: Ambulatorio di Allergologia, Clinica San Carlo, Paderno Dugnano, Italy. r.asero@libero.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Asero
authors.forename: Alberto
authors.initials: A
authors.lastname: Tedeschi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Coppola
authors.forename: Samantha
authors.initials: S
authors.lastname: Griffini
authors.forename: Paolo
authors.initials: P
authors.lastname: Paparella
authors.forename: Piersandro
authors.initials: P
authors.lastname: Riboldi
authors.forename: Angelo V
authors.initials: AV
authors.lastname: Marzano
authors.forename: Daniele
authors.initials: D
authors.lastname: Fanoni
authors.forename: Massimo
authors.initials: M
authors.lastname: Cugno
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000032:analysis; D002908:Chronic Disease; D015942:Factor VIIa / Q000032:analysis; D005174:Factor XII / Q000032:analysis; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011516:Prothrombin; D012867:Skin / Q000737:chemistry; D013925:Thromboplastin / Q000032:analysis / Q000378:metabolism*; D014581:Urticaria / Q000097:blood / Q000209:etiology* / Q000378:metabolism
chemical_list: D001779:Blood Coagulation Factors; D005338:Fibrin Fibrinogen Degradation Products; D010446:Peptide Fragments; C036309:fibrin fragment D; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D005174:Factor XII; D013925:Thromboplastin; D015942:Factor VIIa