Procalcitonin levels in community-acquired pneumonia – correlation with aetiology and severity

Abstract

We studied procalcitonin (PCT) levels at hospital admittance and their association with aetiology and severity in patients with community-acquired pneumonia (CAP). Median PCT concentrations were higher in bacteraemic patients than in those without bacteraemia (6.11 μg/L vs 0.34 μg/L, p = 0.0002), in patients with non-bacteraemic pneumococcal aetiology than in those infected with other classic bacteria (1.18 vs 0.18, p = 0.038), and in patients with pneumococcal as compared with viral aetiology (2.43 vs 0.24, p = 0.017). When aetiology, bacteraemia and severity according to the pneumonia severity index (PSI) were included in logistic regression analyses with PCT > 0.5 as a dependent variable, the odds ratio (OR) for non-bacteraemic pneumococcal aetiology was 5.7 (p = 0.008) and 3.0 ( p = 0.1) for PSI 4–5. A separate analysis for bacteraemia and PSI 4–5 showed an OR of 17.5 (p = 0.008) and 2.7 (p = 0.092), respectively. In CAP patients, high PCT seems to be a good marker for invasive disease and pneumococcal aetiology. As a predictor of severity it appears to be less important.

Keywords::

• Bacterial pneumonia
• C-reactive protein
• pneumonia severity index
• procalcitonin
• viral

Acknowledgments

The authors thank Dr Lars-Olof Hansson, Department of Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden for contributing data regarding inflammatory markers.

Declaration of interest: The study was supported by grants from Karolinska Institutet. The funding source had no role in study design, data collection, data analysis or interpretation, or writing of the report. The authors declare that they have no conflicts of interest.

Notice of correction

The Early Online version of this article published online ahead of print on 8 Sep 2014 contained errors in Table I.