title: Urinary leukotriene E4 levels in high-altitude pulmonary edema. A possible role for inflammation.
abstract: OBJECTIVE
  Inflammation may contribute to the pathogenesis of high-altitude pulmonary edema (HAPE). This study was designed to determine whether a marker of inflammation, urinary leukotriene E4 (LTE4), is elevated in patients with HAPE.
  
  
  METHODS
  We conducted a case-control study to collect clinical data and urine samples from HAPE patients and healthy control subjects at moderate altitude (> or = 2727 m), and follow-up urine samples from HAPE patients following their return to low altitude (< or = 1,600 m).
  
  
  METHODS
  Five medical clinics in Summit County, Colorado.
  
  
  METHODS
  Questionnaire data were evaluated in 71 HAPE patients and 36 control subjects. Urinary LTE4 levels were determined from a random subset of 38 HAPE patients and 10 control subjects presenting at moderate altitude, and on 5 HAPE patients who had returned to low altitude.
  
  
  RESULTS
  Using an enzyme immunoassay technique, urinary LTE4 levels were found to be significantly higher in HAPE patients (123 [16 to 468] pg/mg creatinine, geometric mean [range]) than in control subjects (69 [38 to 135]), p = 0.02. Following return to low altitude, urinary LTE4 levels fell significantly from 122 (41.8 to 309) to 53.6 (27.6 to 104) pg/mg creatinine (p = 0.05). Urinary LTE4 levels were not related to age, sex, time at altitude, physical condition or habitual exercise, recent use of alcohol or nonsteroidal anti-inflammatory drugs (NSAIDs), or oxygen saturation. Clinical factors associated with HAPE included male sex, regular exercise, and recent use of NSAIDs.
  
  
  CONCLUSIONS
  We conclude that urinary LTE4 levels are elevated in patients with HAPE, supporting the view that HAPE involves inflammatory mechanisms.
authors.affiliation: Pulmonary Disease and Critical Care Medicine Unit, University of Vermont College of Medicine, Burlington 05405, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Kaminsky
authors.forename: K
authors.initials: K
authors.lastname: Jones
authors.forename: R B
authors.initials: RB
authors.lastname: Schoene
authors.forename: N F
authors.initials: NF
authors.lastname: Voelkel
mesh_terms: D000328:Adult; D000531:Altitude; D016022:Case-Control Studies; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007249:Inflammation / Q000503:physiopathology; D017999:Leukotriene E4 / Q000502:physiology / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011654:Pulmonary Edema / Q000652:urine*; D012307:Risk Factors
chemical_list: D017999:Leukotriene E4; D003404:Creatinine