Pancreatic Stone Protein Predicts Positive Sputum Bacteriology in Exacerbations of COPD

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 = .03) and healthy control subjects (14.0 ng/mL; 95% CI, 12.0-19.0; P P 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 Conclusions Serum PSP/reg level might represent a promising new biomarker to identify bacterial etiology of COPD exacerbation. Trial registry Current Controlled Trials Database; No.: ISRCTN-77261143; URL: http://www.controlled-trials.com/isrctn