Diagnostic and clinical value of C reactive protein and interleukin 6 serum levels in children with Streptococcus pneumoniae
Objectives: To determine the impact of C reactive protein (CRP) and interleukin (IL) 6 on Streptococcus pneumoniae (S. pneumonia) Methods: Eight eight children with community acquired pneumonia (CAP) were enrolled. Blood or pleural fluid cultures or polymerase chain reaction (PCR) assays was performed to identify the causes of CAP. Serum levels of CRP and IL 6 were analyzed. Pearson correlation analysis was performed to assess the relationship between levels of CRP and IL 6. Receiver operating characteristic (ROC) analysis was used to investigate the diagnostic tests. Results: Among the 88 patients, 75 cases were identified as S. pneumonia (34 cases) other types of bacterial pneumonia (12) viral pneumonia (22) and mycoplasma pneumonia (7) The levels of CRP and IL 6 were both significantly increased in S. pneumonia patients compared to viral pneumonia or mycoplasma pneumonia (P 0.05) Additionally, there were strong relationships between CRP and IL 6 level in patients with S. pneumonia (R2 0.893, P 0.003) There were relatively weak relationships in other types of bacterial pneumonia (R2 0.604, P 0.037) but there were no relationships in patients with viral pneumonia (R2 0.232, P 0.580) or with mycoplasma pneumonia (R2 0.226, P 0.591) ROC showed that area under the curve (AUC 0.841) with CRP threshold value of 250 mg/L and IL 6 of 800 pg/ml (sensitivity: 86.7% specificity: 87.1% for distinguishing between S. pneumonia from other pneumonia. Conclusion: Combined application of CRP and IL 6 has clinical usefulness in distinguishing between S. pneumonia from other pneumonia.