Predicting the causative pathogen in pediatric hemodialysis catheter infections before culture results: the role of inflammatory indices.

BACKGROUND

Catheter-related infections are a major cause of morbidity in pediatric hemodialysis (HD) patients. We evaluated whether complete blood count (CBC)-derived inflammatory indices could help distinguish Gram-positive from Gram-negative pathogens, providing complementary information for early clinical assessment, risk stratification and antimicrobial stewardship. Evidence in pediatric HD catheter-related infections remains limited.

METHODS

In this retrospective study, 123 culture-proven catheter-related infection episodes from 34 pediatric HD patients (2015-2025) were analyzed by Gram status and infection type: catheter-related bloodstream infection (CRBSI) or exit-site infection (ESI). CBC-derived inflammatory indices, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI), were calculated from pretreatment admission CBC.

RESULTS

Gram-negative pathogens accounted for 52 episodes (42.3%) and were associated with higher NLR, PLR, MLR, SII, and SIRI values and longer hospitalization than Gram-positive episodes (median 20 vs. 11 days; all p < 0.05). NLR showed the highest discriminatory performance for Gram-negative infection (AUC 0.721; cut-off 3.8; sensitivity 80%, specificity 60%), followed by SII (AUC 0.696). Subgroup analyses by infection type showed broadly consistent discriminatory patterns. All indices correlated with C-reactive protein (CRP) and length of stay. In multivariate analysis, CRBSI, lower hemoglobin, and higher CRP independently predicted prolonged hospitalization.

CONCLUSIONS

CBC-derived inflammatory indices, particularly NLR and SII, showed moderate discrimination between Gram-negative and Gram-positive catheter-related infections in pediatric HD patients. Their immediate availability may provide useful complementary information on pathogen likelihood and infection severity while awaiting culture confirmation, supporting early risk assessment and antimicrobial stewardship without replacing standard empirical therapy.