Utility of serum procalcitonin values in patients with acute exacerbations of chronic obstructive pulmonary disease: a cautionary note

ility of serum procalcitonin values in patients with acute exacerbations of chronic obstructive pulmonary disease: a cautionary note Original Research (3742) Total Article Views Authors: Falsey AR, Becker KL, Swinburn AJ, Nylen ES, Snider RH, Formica MA, Hennessey PA, Criddle MM, Peterson DR, Walsh EE Published Date February 2012 Volume 2012:7 Pages 127 - 135 DOI: http://dx.doi.org/10.2147/COPD.S29149 Received: 15 December 2011 Accepted: 12 January 2012 Published: 23 February 2012 Ann R Falsey1,2, Kenneth L Becker3, Andrew J Swinburne2, Eric S Nylen3, Richard H Snider3, Maria A Formica2, Patricia A Hennessey2, Mary M Criddle2, Derick R Peterson4, Edward E Walsh1,2 1Department of Medicine, University of Rochester, 2Rochester General Hospital, Rochester, NY, 3Veterans Affairs Medical Center and George Washington University, Washington DC, 4Biostatistics and Computational Biology, University of Rochester, Rochester, NY, USA Background: Serum procalcitonin levels have been used as a biomarker of invasive bacterial infection and recently have been advocated to guide antibiotic therapy in patients with chronic obstructive pulmonary disease (COPD). However, rigorous studies correlating procalcitonin levels with microbiologic data are lacking. Acute exacerbations of COPD (AECOPD) have been linked to viral and bacterial infection as well as noninfectious causes. Therefore, we evaluated procalcitonin as a predictor of viral versus bacterial infection in patients hospitalized with AECOPD with and without evidence of pneumonia. Methods: Adults hospitalized during the winter with symptoms consistent with AECOPD underwent extensive testing for viral, bacterial, and atypical pathogens. Serum procalcitonin levels were measured on day 1 (admission), day 2, and at one month. Clinical and laboratory features of subjects with viral and bacterial diagnoses were compared. Results: In total, 224 subjects with COPD were admitted for 240 respiratory illnesses. Of these, 56 had pneumonia and 184 had AECOPD alone. A microbiologic diagnosis was made in 76 (56%) of 134 illnesses with reliable bacteriology (26 viral infection, 29 bacterial infection, and 21 mixed viral bacterial infection). Mean procalcitonin levels were significantly higher in patients with pneumonia compared with AECOPD. However, discrimination between viral and bacterial infection using a 0.25 ng/mL threshold for bacterial infection in patients with AECOPD was poor. Conclusion: Procalcitonin is useful in COPD patients for alerting clinicians to invasive bacterial infections such as pneumonia but it does not distinguish bacterial from viral and noninfectious causes of AECOPD.