Differentiated associations of inflammatory indices with laboratory-defined organ injury/involvement and hospitalization length in pediatric respiratory tract infections.

BACKGROUND

To analyze the associations of inflammatory indices with laboratory-defined organ injury/involvement and hospitalization length in pediatric respiratory tract infections (RTIs).

METHODS

In this study, logistic regression analyses were performed to examine the associations between inflammatory index levels and laboratory-defined cardiac injury, liver injury, and kidney involvement. Receiver operating characteristic (ROC) curve analyses were performed to evaluate the discriminative ability of inflammatory indices for laboratory-defined organ injury/involvement. Linear regression analyses were conducted to assess the associations between inflammatory index levels and hospitalization length.

RESULTS

Lower levels of neutrophils, C-reactive protein (CRP), Systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-platelet ratio (NPR), and CRP-to-lymphocyte ratio (CLR) were associated with the presence of laboratory-defined cardiac injury. Higher lymphocyte levels and lower levels of neutrophils, platelets, CRP, SII, NLR, platelet-to-lymphocyte ratio (PLR), NPR, and CLR were associated with the presence of laboratory-defined liver injury. Higher levels of white blood cells (WBCs), neutrophils, CRP, SII, NLR, PLR, and CLR, together with lower lymphocyte levels, were associated with the presence of laboratory-defined kidney involvement. ROC curve analyses suggested that NLR, SII, and CLR had a relatively high discriminative ability for laboratory-defined cardiac injury; SII, NLR, and PLR for liver injury; and NLR, CLR, and NPR for laboratory-defined kidney involvement. Higher levels of WBCs, lymphocytes, CRP, NPR, and CLR, along with lower levels of platelets and Hb, were associated with longer hospitalization.

CONCLUSION

Inflammatory indices, particularly composite indices, were associated with laboratory-defined organ injury/involvement and longer hospitalization in children with RTIs, suggesting their potential value as non-invasive exploratory markers. Future longitudinal studies are needed to confirm their prognostic utility.