Purpose or Case Report: CAP is a worldwide contributor to morbidity and mortality in children. Radiogenomics is an emerging specialty which correlates imaging features to gene expression to predict disease severity, therapeutic response and clinical outcomes. A genomic score termed Molecular Distance to Health (MDTH) is a biomarker that measures the global transcriptional perturbation in blood and has been shown to correlate with disease severity in pediatric CAP (Wallihan R, Front. Cell. Infect. Microbiol. 2018). This study was undertaken to determine whether abnormalities on chest radiographs correlate with genomic and clinical markers of disease severity.
Methods & Materials: Initial chest radiographs of children (age 2 months - 18 years) admitted to a single institution between February 1, 2011, and May 10, 2012 for CAP were reviewed retrospectively. An experienced pediatric radiologist blinded to the clinical data recorded abnormalities including peribronchial thickening, adenopathy, pleural effusion, and pulmonary opacities (characterized as band-like, streaky, consolidative, round or other). Clinical and laboratory data were collected including length of hospitalization (LOS), days of respiratory support (DOS), days of fever (DOF), blood culture, CBC, procalcitonin, C-reactive protein (CRP), and nasopharyneal/oropharyngeal swabs for viral and bacterial pathogen detection, and whole blood for transcriptional analysis and MDTH calculation. We used chest radiographic findings to classify patients according to clinical variables and the genomic MDTH score. We performed two-tailed unpaired t-test to compare groups stratified by radiological findings.
Results: 144 chest radiographs were reviewed. Patients with pleural effusion (right or left) (n=43, 30%) showed significantly longer LOS, DOS, DOF, CRP and higher MDTH scores (all p <0.05) compared with those patients without pleural effusion (n=101). Likewise, patients with consolidative opacity (air space opacity) (n=82, 57%) showed significantly longer LOS, DOF, and higher MDTH scores (all p <0.05) compared with those patients without a consolidative opacity (n=62).
Conclusions: In a cohort of children hospitalized with CAP, we identified chest radiographic findings that classified patients according to: 1) clinical markers of disease severity and 2) the MDTH genomic score. Combining radiographic and genomic markers should contribute to a more precise clinical disease severity classification in pediatric CAP.