title: Inflammation in deep vein thrombosis and the development of post-thrombotic syndrome: a prospective study.
abstract: BACKGROUND
  The aim of this study was to investigate whether inflammatory markers (interleukin-6 [IL-6] and C-reactive protein [CRP]) in the acute phase of deep vein thrombosis (DVT) are associated with elevated venous outflow resistance (VOR), thrombosis score (TS), reflux and the development of clinical post-thrombotic syndrome (PTS).
  
  
  METHODS
  In 110 patients with a first DVT, plasma concentrations of IL-6 and CRP were determined on the day of admission. VOR, TS and reflux were measured 7 days, 1 and 3 months after diagnosis. After 1 year patients were evaluated for PTS using the Clinical, Etiologic, Anatomic and Pathophysiologic (CEAP) classification and Villalta scale.
  
  
  RESULTS
  Median levels of IL-6 and CRP were 7 pg mL(-1) and 21 mg L(-1), respectively. After 3 months, VOR was elevated in 33 patients (30%), TS in 33 (30%) and reflux in 57 (52%). Incidence of PTS was 36.7% using CEAP>or=3 and 35.4% using Villalta-scale>or=5. Elevated levels of IL-6 and CRP were related to higher outcomes of VOR after 3 months [relative risks (RR) 2.4 (95% CI 1.5-3.9) and 1.4 (1.1-3.3), respectively] and for IL-6 to TS [1.5 (1.1-2.1)]. For reflux no relation was found. After 90 days, elevated outcomes of VOR, TS and reflux were related to PTS after 1 year. The association of IL-6 and CRP with PTS was weak using the CEAP classification with a RR of 1.2 (0.7-2.2) and 1.8 (0.9-3.3) and absent according to the Villalta scale 0.6 (0.2-1.4) and 1.2 (0.6-2.5), respectively.
  
  
  CONCLUSIONS
  The results of this study suggest that inflammation might play a role in incomplete thrombus clearance, venous outflow obstruction and the development of PTS after 1 year.
authors.affiliation: Department of General Internal Medicine, Radbound University Nijmegen Medical Centre, and Canisius Wilhelmina Hospital, Nijmegen, The Netherlands. E.Roumen@aig.umcn.nl
authors.forename: E M
authors.initials: EM
authors.lastname: Roumen-Klappe
authors.forename: M C H
authors.initials: MC
authors.lastname: Janssen
authors.forename: J
authors.initials: J
authors.lastname: Van Rossum
authors.forename: S
authors.initials: S
authors.lastname: Holewijn
authors.forename: M M J A
authors.initials: MM
authors.lastname: Van Bokhoven
authors.forename: K
authors.initials: K
authors.lastname: Kaasjager
authors.forename: H
authors.initials: H
authors.lastname: Wollersheim
authors.forename: M
authors.initials: M
authors.lastname: Den Heijer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications*; D008297:Male; D008875:Middle Aged; D054070:Postthrombotic Syndrome / Q000209:etiology*; D011446:Prospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D014689:Venous Insufficiency; D020246:Venous Thrombosis / Q000473:pathology*
chemical_list: D015415:Biomarkers