title: Activation of blood coagulation in plasma from chronic urticaria patients with negative autologous plasma skin test.
abstract: BACKGROUND
  Skin reactivity to the intradermal injection of autologous serum (autologous serum skin test - ASST) and/or plasma (autologous plasma skin test - APST) is thought to identify chronic urticaria (CU) patients with an autoimmune/autoreactive disease. Immune-mediated inflammation and coagulation are strictly linked, and coagulation activation has been described in CU patients as shown by the elevation of plasma prothrombin fragment F1+2 and, in severe cases, of d-dimer as well.
  
  
  OBJECTIVE
  The aim of this study was to evaluate whether the coagulation cascade is activated in APST-negative CU patients as it has been described in CU patients with an autoreactive disease.
  
  
  METHODS
  A total of 43 adults with CU (M/F 15/28; mean age 43.5 years; 16 APST-negative patients and 27 APST-positive) and 30 healthy subjects were studied. Prothrombin fragment F1+2, d-dimer and C-reactive protein (CRP) plasma levels were measured by ELISA.
  
  
  RESULTS
  Prothrombin fragment F1+2 and d-dimer were elevated in seven of 16 APST-negative CU patients. The activation of the coagulation cascade was associated with disease severity. Men were more prevalent in idiopathic than in autoreactive CU patients (M/F: 10/6 vs. 5/22; P<0.001). In patients with APST-negative CU, mean F1 + 2 level [242.8 ± 33.7 pmol/L (ESM)] was higher than in normal controls (151.8 ± 9.09 pmol/L; P=0.002) but lower than in autoreactive patients (526.2 ± 97.8 pmol/L; P=0.05). Similarly, mean d-dimer level was higher than in normal controls (484.2 ± 148.3 ng/mL vs. 229.5 ± 16.7 ng/mL; P=0.03) but lower than in autoreactive patients (1142.2 ± 317.4 ng/mL; P=0.05). In contrast, mean CRP was lower than in autoreactive patients (1.06 ± 0.32 μg/mL vs. 3.09 ± 0.74 μg/mL; P=0.02) but not different from normal subjects (0.78 ± 0.09 μg/mL; NS).
  
  
  CONCLUSIONS
  Autologous plasma skin test-negative CU prevails in men; in these patients the coagulation cascade is activated although with a lower intensity than in patients with autoreactive disease.
authors.affiliation: Ambulatorio di Allergologia, Clinica San Carlo, Paderno Dugnano (MI), Italy. r.asero@libero.it
authors.forename: R
authors.initials: R
authors.lastname: Asero
authors.forename: M
authors.initials: M
authors.lastname: Cugno
authors.forename: A
authors.initials: A
authors.lastname: Tedeschi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001777:Blood Coagulation / Q000502:physiology*; D001780:Blood Coagulation Tests; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011516:Prothrombin; D012882:Skin Tests; D014581:Urticaria / Q000097:blood*; D055815:Young Adult
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D010446:Peptide Fragments; C036309:fibrin fragment D; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D002097:C-Reactive Protein