title: Pulmonary production of osteopontin in humans: effects of left ventricular systolic dysfunction and cardiopulmonary bypass.
abstract: Background: We evaluated pulmonary production of osteopontin (OPN) in left ventricular systolic dysfunction (LVSD) and after cardiopulmonary bypass surgery (CPB). OPN is a phosphoglycoprotein involved in inflammation and remodeling. In subjects with LVSD, plasma OPN correlates with prognosis but its origin is unknown. We hypothesized that the lungs produce OPN and that this could be affected by LVSD and CPB.Methods and Results: Subjects with (n =57; left ventricular ejection fraction [LVEF] 32 ± 8%) and without (n = 63; LVEF 59 ± 7%) LVSD were studied during CPB. Arterial and venous OPN plasma levels were determined. Arterial and venous OPN levels were higher in LVSD (P = .0290). For both groups, levels dropped 1 hour after surgery and nearly doubled 24 hours after (P ! .0001 vs basal).Notably, there was a significant positive arteriovenous gradient with arterial levels higher than venous levels. Arteriovenous differences were statistically significant at baseline (P = .0120) and 1 hour (P < .0001) but not at 24 hours (P = .0649). Arterial levels in heart failure correlated inversely with renal function(P = .016) and positively with mean pulmonary pressure (P = .028), heart rate (P = .036), and C-reactive protein (P = .047).Conclusions: There is production of circulating OPN by the lungs, unaffected by LVSD or CPB. This likely represents an overflow from local lung production and does not contribute to increased levels in LVSD or after CPB.
authors.affiliation: Department of Anesthesiology, Montreal Heart Institute and Universite de Montreal, Montreal, Quebec, Canada; Research Center, Montreal Heart Institute and  Universite de Montreal, Montreal, Quebec, Canada
authors.forename: Christian
authors.initials: C
authors.lastname: Ayoub
authors.forename: Anna
authors.initials: A
authors.lastname: Nozza
authors.forename: André
authors.initials: A
authors.lastname: Denault
authors.forename: Alain
authors.initials: A
authors.lastname: Deschamps
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Dupuis
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053495:Osteopontin / Q000097:blood*; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000097:blood* / Q000503:physiopathology / Q000601:surgery*
chemical_list: D015415:Biomarkers; D053495:Osteopontin