title: Pancreatic stone protein predicts positive sputum bacteriology in exacerbations of COPD.
abstract: BACKGROUND
  Pancreatic stone protein/regenerating protein (PSP/reg) serum levels are supposed to be increased in bacterial inflammation. PSP/reg levels also might be useful, therefore, as a predictor of bacterial infection in COPD.
  
  
  METHODS
  Two hundred consecutive patients presenting to the ED due to acute exacerbation of COPD were prospectively assessed. Patients were evaluated based on clinical, laboratory, and lung functional parameters at admission (exacerbation) and after short-term follow-up (14-21 days). PSP/reg serum values were measured by a newly developed enzyme-linked immunosorbent assay.
  
  
  RESULTS
  PSP/reg levels were elevated in subjects with COPD exacerbation (23.8 ng/mL; 95% CI, 17.1-32.7) when compared with those with stable disease (19.1 ng/mL; 95% CI, 14.1-30.4; P 5 .03) and healthy control subjects (14.0 ng/mL; 95% CI , 12.0-19.0; P , .01). Higher PSP/reg values were observed in exacerbations with positive sputum bacteriology compared with those with negative sputum bacteriology (26.1 ng/mL [95% CI, 19.2-38.1] vs 20.8 ng/mL [95% CI , 15.6-27.2]; P , .01). Multivariate regression analysis revealed PSP/reg level as an independent predictor of positive sputum bacteriology. A combination of a PSP/reg cutoff value of . 33.9 ng/mL and presence of discolored sputum had a specificity of 97% to identify patients with pathogenic bacteria on sputum culture. In contrast, PSP/reg levels , 18.4 ng/mL and nonpurulent sputum ruled out positive bacterial sputum culture (sensitivity, 92%). In survival analysis, high PSP/reg levels at hospital admission were associated with increased 2-year mortality.
  
  
  CONCLUSIONS
  Serum PSP/reg level might represent a promising new biomarker to identify bacterial etiology of COPD exacerbation.
authors.affiliation: Clinic of Pulmonary Medicine and Respiratory Cell Research, Diabetes and Clinical Nutrition, University Hospital, Basel.
authors.forename: Andreas
authors.initials: A
authors.lastname: Scherr
authors.affiliation: Pancreatitis Research Laboratory, University Hospital Zurich, Zurich.
authors.forename: Rolf
authors.initials: R
authors.lastname: Graf
authors.affiliation: Pancreatitis Research Laboratory, University Hospital Zurich, Zurich.
authors.forename: Martha
authors.initials: M
authors.lastname: Bain
authors.affiliation: Clinic of Endocrinology, Diabetes and Clinical Nutrition, University Hospital, Basel.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Christ-Crain
authors.affiliation: Medical University Clinic, Kantonsspital Aarau AG, Aarau, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Müller
authors.affiliation: Clinic of Pulmonary Medicine and Respiratory Cell Research, Diabetes and Clinical Nutrition, University Hospital, Basel.
authors.forename: Michael
authors.initials: M
authors.lastname: Tamm
authors.affiliation: Clinic of Pulmonary Medicine and Respiratory Cell Research, Diabetes and Clinical Nutrition, University Hospital, Basel. Electronic address: dstolz@uhbs.ch.
authors.forename: Daiana
authors.initials: D
authors.lastname: Stolz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000097:blood / Q000150:complications* / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D053208:Kaplan-Meier Estimate; D051847:Lithostathine / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000382:microbiology* / Q000401:mortality; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013183:Sputum / Q000382:microbiology*
chemical_list: D015415:Biomarkers; D051847:Lithostathine; C497617:REG1A protein, human