Oncostatin M: a novel biomarker for bacterial pneumonia in children

Backgrounds: Oncostatin M (OSM), a cytokine belonging to the interleukin 6 cytokine family, is a potential biomarker of pneumonia in adults. There have been no studies investigating the role of OSM in paediatric pneumonia. The aim of this study was to assess the diagnostic accuracy of OSM in diagnosing bacterial pneumonia in children admitted to the paediatric intensive care unit (PICU).

Methods: Children with clinician diagnosed pneumonia confirmed on chest radiograph were recruited from the Royal Belfast Hospital for Sick Children between April 2020 and December 2022. Detailed clinical data was recorded including the paediatric sequential organ failure assessment (pSOFA), treatments given, levels of care, length of stay and survival. Blood plasma was collected and OSM tested by ELISA. A final diagnosis of bacterial, viral or mixed viral and bacterial pneumonia was provided by an independent paediatric intensivist based on clinical data and results from blood culture, broncheoalveolar lavage and sputum.

Results: A total of 27 children were included in the study. The median age was 1.7 (IQR: 0.5-6.8) years and 48% were male. 22/27 (81%) received invasive ventilation, and 3/27 (11%) died. There were 15/27 (56%) cases of viral pneumonia, 9/27 (33%) cases of bacterial or mixed pneumonia and 3/27 (11%) with an unclear aetiology. OSM demonstrated excellent diagnostic test accuracy for identifying bacterial pneumonia with an area under the curve (AUC) of 0.89 (95% CI 0.72-1.1). The optimum cut-off for OSM was 5.3pg/ml with a sensitivity of 0.93 (95% CI 0.68 to 0.99) and specificity of 0.78 (95% CI 0.45 to 0.96).

Conclusions/Learning Points: This small cohort study provides the first evidence that OSM could be used as a blood biomarker of bacterial pneumonia in children.