Biomarkers and Disease Severity in Children With Community-Acquired Pneumonia

Abstract

BACKGROUND: Host biomarkers predict disease severity in adults with community-acquired pneumonia (CAP). We evaluated the association of the white blood cell (WBC) count, absolute neutrophil count (ANC), C-reactive protein (CRP), and procalcitonin with the development of severe outcomes in children with CAP. METHODS:We performed a prospective cohort study of children 3 months to 18 years of age with CAP in the emergency department. The primary outcome was disease severity: mild (discharged from the hospital), mild-moderate (hospitalized but not moderate-severe or severe), moderate-severe (eg, hospitalized with receipt of intravenous fluids, supplemental oxygen, complicated pneumonia), and severe (eg, intensive care, vasoactive infusions, chest drainage, severe sepsis). Outcomes were examined within the cohort with suspected CAP and in a subset with radiographic CAP.RESULTS: Of 477 children, there were no statistical differences in the median WBC count, ANC, CRP, or procalcitonin across severity categories. No biomarker had adequate discriminatory ability between severe and nonsevere disease (area under the curve [AUC]: 0.53-0.6 for suspected CAP and 0.59-0.64 for radiographic CAP). In analyses adjusted for age, antibiotic use, fever duration, and viral pathogen detection, CRP was associated with moderate-severe disease (odds ratio 1.12; 95% confidence interval, 1.0-1.25). CRP and procalcitonin revealed good discrimination of children with empyema requiring chest drainage (AUC: 0.83) and sepsis with vasoactive infusions (CRP AUC: 0.74; procalcitonin AUC: 0.78), although prevalence of these outcomes was low.CONCLUSIONS: WBC count, ANC, CRP, and procalcitonin are generally not useful to discriminate nonsevere from severe disease in children with CAP, although CRP and procalcitonin may have some utility in predicting the most severe outcomes. WHAT'S KNOWN ON THIS SUBJECT: Prognostic tools are limited for children with community-acquired pneumonia (CAP). Host biomarkers, including C-reactive protein (CRP) and procalcitonin, have been shown to be associated with severe clinical outcomes in adults with CAP. Data in children are limited.WHAT THIS STUDY ADDS: White blood cell count, CRP, and procalcitonin are generally not useful to discriminate overall disease severity in children with CAP. CRP and procalcitonin may have utility in predicting the most severe outcomes, but research is necessary to validate these findings.

Incidence and Risk Factors for Severe Pneumonia in Children Hospitalized with Pneumonia in Ujjain, India

“…The present study evaluated host biomarkers like theTLC count, which was useful only in the presence of moderate leukocytosis. Generally, like the conclusion in other studies, it can be concluded that TLC and neutrophil percentage were not useful in distinguishing pneumonia from severe disease [40]. However, a CRP cut-off of 20 mg/L had a high specificity (90%) and positive predictive value (92%) to distinguish non-severe from severe disease.…”

Use of saliva sample to detect C‐reactive protein in children with pneumonia

“…The diagnostic utility of inflammatory markers in pediatric community‐acquired pneumonia (CAP) has been reported in the post‐pneumococcal vaccination era 4 . Several biomarkers are used for treatment evaluation in pediatric patients with pneumonia 5,6 . C‐reactive protein (CRP) is a serum biomarker useful for the treatment evaluation of pneumonia due to its high correlation with etiology and severity 4,7 .…”

The prognostic value of C‐reactive protein for children with pneumonia

“…Nonetheless, a 2008 meta‐analysis including a total of 1230 children concluded that an elevated concentration of CRP only weakly predicts a bacterial aetiology 8 . Yet other studies suggest that CRP can be a useful prognostic marker for pneumonia‐associated complications, 9‐14 and especially severe complications such as the need for a chest drain 15 …”