title: Ubiquitin Urine Levels in Burn Patients.
abstract: The objective of this study was to determine whether urine ubiquitin levels are elevated after burns and to assess whether urine ubiquitin could be useful as a noninvasive biomarker for burn patients. Forty burn patients (%TBSA: 20 ± 22; modified Baux scores: 73 ± 26) were included (control: 11 volunteers). Urine was collected in 2-hour intervals for 72 hours, followed by 12-hour intervals until discharge from the intensive care unit. Ubiquitin concentrations were analyzed by enzyme linked immunosorbent assay and Western blot. Total protein was determined with a Bradford assay. Patient characteristics and clinical parameters were documented. Urine ubiquitin concentrations, renal ubiquitin excretion, and excretion rates were correlated with patient characteristics and outcomes. Initial urine ubiquitin concentrations were 362 ± 575 ng/ml in patients and 14 ± 18 ng/ml in volunteers (P < .01). Renal ubiquitin excretion on day 1 was 292.6 ± 510.8 μg/24 hr and 21 ± 27 μg/24 hr in volunteers (P < .01). Initial ubiquitin concentrations correlated with modified Baux scores (r = .46; P = .02). Ubiquitin levels peaked at day 6 postburn, whereas total protein concentrations and serum creatinine levels remained within the normal range. Total renal ubiquitin excretion and excretion rates were higher in patients with %TBSA ≥20 than with %TBSA <20, in patients who developed sepsis/multiple organ failure than in patients without these complications and in nonsurvivors vs survivors. These data suggest that ubiquitin urine levels are significantly increased after burns. Renal ubiquitin excretion and/or excretion rates are associated with %TBSA, sepsis/multiple organ failure, and mortality. Although these findings may explain previous correlations between systemic ubiquitin levels and outcomes after burns, the large variability of ubiquitin urine levels suggests that urine ubiquitin will not be useful as a noninvasive disease biomarker.
authors.affiliation: From the *Department of Surgery, Burn and Shock Trauma Research Institute, and †Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
authors.forename: Yee M
authors.initials: YM
authors.lastname: Wong
authors.forename: Heather M
authors.initials: HM
authors.lastname: LaPorte
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Albee
authors.forename: Todd A
authors.initials: TA
authors.lastname: Baker
authors.forename: Harold H
authors.initials: HH
authors.lastname: Bach
authors.forename: P Geoff
authors.initials: PG
authors.lastname: Vana
authors.forename: Ann E
authors.initials: AE
authors.lastname: Evans
authors.forename: Richard L
authors.initials: RL
authors.lastname: Gamelli
authors.forename: Matthias
authors.initials: M
authors.lastname: Majetschak
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D001830:Body Surface Area; D002056:Burns / Q000175:diagnosis / Q000401:mortality* / Q000652:urine*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012016:Reference Values; D015996:Survival Rate; D025801:Ubiquitin / Q000652:urine*
chemical_list: D015415:Biomarkers; D025801:Ubiquitin