(1585) Investigation of Systemic Immune-Inflammation Biomarkers in Pediatric Sepsis

Introduction: Multiple clinical biomarkers have been investigated to risk stratify patients with sepsis. Systemic immune-inflammation biomarkers are associated with sepsis mortality in adults and predictors of early onset sepsis in neonates. In the pediatric sepsis literature this data is lacking. We hypothesized that biomarkers of systemic immune-inflammation including neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and systemic immune-inflammation index (SII), would be associated with higher pediatric sepsis mortality.

Methods: We performed a single-center retrospective cohort study. Inclusion criteria were patients aged 0-18 years old who were admitted to the PICU with sepsis from 2015-2023. Patients were excluded if they did not have a complete blood count with differential performed on admission. Univariate cox proportional hazard models were constructed for our 3 biomarkers. Next, multivariate cox proportional hazard models were constructed using stepwise backward selection. Only one severity of illness score was included in each model due to collinearity. Models were then compared using area under the receiver operator characteristic curves (AUC).

Results: 423 patients were included in the study (390 survivors and 33 non-survivors). Non-survivors had higher Pediatric Index of Mortality (PIM) and Pediatric Risk of Mortality (PRISM) scores. There were no differences in age, weight, race, or sex. A higher PLR was associated with higher mortality [HR:1.002 (1.001-1.003), p:0.003]. The addition of PLR to PIM increased the model’s discriminative ability [AUC from 0.70 PIM alone to 0.74 PIM+PLR]. The addition of PLR to PRISM increased the model’s discriminative ability [AUC 0.64 PRISM alone to AUC 0.70 PRISM+PLR]. There were no differences in cox proportional hazards for either NLR or SII.

Conclusions: In this cohort of children with sepsis an increased PLR is associated with higher mortality. Additionally, the addition of PLR to either PIM or PRISM increased the discriminative ability of both scoring systems for prediction of mortality. Admission PLR is a simple index that is readily available and should be considered to help risk stratify patients with sepsis.