Abnormal expression and clinical value analysis of long noncoding RNA cancer susceptibility candidate 2 in children with severe pneumonia complicated with respiratory failure.

Objective: Severe pneumonia occurs commonly in children and is the main cause of clinical infant mortality. This study tested the expression pattern of long noncoding RNA cancer susceptibility candidate 2 (CASC2) in the serum of children with severe pneumonia and explored its clinical values.

Methods: Serum levels of CASC2 were detected in 145 children with severe pneumonia. All cases were divided into two groups based on their respiratory failure (RF) condition. Receiver operating characteristic (ROC) and Kaplan-Meier (K-M) curves were plotted for the diagnostic and prognostic ability evaluation. Multivariate cox regression analysis was done for the examination of independent influence factors.

Results: The serum levels of CASC2 significantly decreased in children with severe pneumonia in contrast with healthy individuals and reached the lowest value in those with RF. Serum CASC2 can distinguish severe pneumonia and predicted the development of RF. Based on the 28-day survival data, cases with low CASC2 levels had a poor survival rate. CASC2 (hazard ratio [HR] = 0.068, 95% confidence interval [CI] = 0.016-0.292, P < 0.001) and age (HR = 2.806, 95% CI = 1.240-6.394, P < 0.001) were independent influence factor for the poor prognosis of children with severe pneumonia.

Conclusion: Downregulation of serum CASC2 was related to the occurrence of RF in children with severe pneumonia and may be a predictor of the poor prognosis. This study will provide a potential biomarker for severe pneumonia treatment in clinic.