Format

Send to

Choose Destination
BMC Anesthesiol. 2014 Nov 15;14:102. doi: 10.1186/1471-2253-14-102. eCollection 2014.

Pre-analytic factors and initial biomarker levels in community-acquired pneumonia patients.

Author information

1
University Department of Medicine, Tellstrasse, CH-5001 Kantonsspital Aarau, Switzerland.
2
Department of Internal Medicine, Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Basel, Basel, Switzerland.
3
Department of Internal Medicine, Bürgerspital Solothurn, Solothurn, Switzerland.
4
Basel University Medical Clinic Liestal, Liestal, Switzerland.
5
Department of Internal Medicine, Kantonsspital Münsterlingen, Münsterlingen, Switzerland.
6
Department of Internal Medicine, Kantonsspital Lucerne, Lucerne, Switzerland.

Abstract

BACKGROUND:

Blood biomarkers are increasingly used to diagnose, guide therapy in, and risk-stratify community-acquired pneumonia (CAP) patients in emergency departments (EDs). How pre-analytic factors affect these markers' initial levels in this population is unknown.

METHODS:

In this secondary analysis of consecutive ED patients with CAP from a large multicentre antibiotic stewardship trial, we used adjusted multivariate regression models to determine the magnitude and statistical significance of differences in mean baseline concentrations of five biomarkers (procalcitonin [PCT], C-reactive protein [CRP], white blood cells count [WBC], proadrenomedullin [ProADM], copeptin) associated with six pre-analytic factors (antibiotic or corticosteroid pretreatment, age, gender, chronic renal failure or chronic liver insufficiency).

RESULTS:

Of 925 CAP patients (median age 73 years, 58.8% male), 25.5% had antibiotic pretreatment, 2.4%, corticosteroid pretreatment, 22.3%, chronic renal failure, 2.4% chronic liver insufficiency. Differences associated with pre-analytic factors averaged 6.1% ± 4.6%; the three largest statistically significant changes (95% confidence interval) were: PCT, +14.2% (+2.1% to +26.4%, p = 0.02) with liver insufficiency; ProADM, +13.2% (+10.2% to +16.1%, p < 0.01) with age above median; CRP, -12.8% (-25.4% to -0.2%, p = 0.05) with steroid pretreatment. In post hoc sensitivity analyses, reclassification statistics showed that these factors did not result in significant changes of biomarker levels across clinically used cut-off ranges.

CONCLUSIONS:

Despite statistically significant associations of some pre-analytic factors and biomarker levels, a clinically relevant influence seems unlikely. Our observations reinforce the concept of using biomarkers in algorithms with widely-separated cut-offs and overruling criteria considering the entire clinical picture.

TRIAL REGISTRATION:

Identifier ISRCTN95122877.

KEYWORDS:

Blood biomarkers; C-reactive protein; Community-acquired pneumonia; Copeptin; Pre-analytic factors; Pretreatment; Proadrenomedullin; Procalcitonin; White blood cells count

PMID:
25419180
PMCID:
PMC4240803
DOI:
10.1186/1471-2253-14-102
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center