title: Elevated plasma endothelin-1 levels and vascular dysregulation in patients with rheumatoid arthritis.
abstract: BACKGROUND
  Contradictory results on plasma endothelin-1 (ET-1) levels in patients with rheumatoid arthritis have been reported in previous studies. We therefore evaluated whether plasma ET-1 levels in patients with rheumatoid arthritis differ from those of normal controls. Since systemically increased levels of ET-1 are known to occur in tandem with primary or secondary vascular dysregulation, we also measured peripheral blood flow by means of nailfold capillaroscopy combined with a cold provocation test.
  
  
  METHODS
  We measured plasma levels of ET-1 in twelve patients with different stages of rheumatoid arthritis by means of a specific radioimmunoassay, and compared ET-1 values to those of healthy controls. Capillary blood flow and the frequency of cold-induced vasospasm were studied in parallel, using nailfold capillaroscopy combined with a cold provocation test.
  
  
  RESULTS
  Plasma ET-1 levels were significantly increased in patients with rheumatoid arthritis (p = 0.01) when compared to controls (2.38+/-0.95 pg/ml vs. 1.53+/-0.38 pg/ml). Capillary blood flow was reduced when compared to our own normal values, and a cold-induced blood standstill was seen in 58% of the patients.
  
  
  CONCLUSIONS
  Patients with rheumatoid arthritis exhibit significantly elevated levels of ET-1, which may be associated with the symptoms of vascular dysregulation observed in nailfold capillaroscopy. Even though the clinical conclusions should be drawn from this study with caution, additional therapy with calcium channel blockers or, possibly in the future, with ET-1 receptor blockers, may be beneficial in patients with rheumatoid arthritis.
authors.affiliation: University Eye Clinic, Basel, Switzerland.
authors.forename: Mona
authors.initials: M
authors.lastname: Pache
authors.forename: Hans A
authors.initials: HA
authors.lastname: Schwarz
authors.forename: Hedwig J
authors.initials: HJ
authors.lastname: Kaiser
authors.forename: Peter
authors.initials: P
authors.lastname: Wüest
authors.forename: Manuel
authors.initials: M
authors.lastname: Klöti
authors.forename: Barbara
authors.initials: B
authors.lastname: Dubler
authors.forename: Josef
authors.initials: J
authors.lastname: Flammer
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000473:pathology; D016022:Case-Control Studies; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D020678:Microscopic Angioscopy; D008875:Middle Aged; D011863:Radioimmunoassay; D012039:Regional Blood Flow; D013997:Time Factors
chemical_list: D019332:Endothelin-1