Biomarkers for risk stratification of febrile neutropenia among children with malignancy: a pilot study.

Background: Patients receiving myelosuppressive chemotherapy remain at increased risk for developing febrile neutropenia (FN). For this heterogeneous population, a biomarker based risk stratification of FN patients may be a useful clinical tool. We hypothesized that serum biomarkers during initial presentation of an FN event could be predictive of subsequent clinical outcome.

Procedure: Eighty-nine FN events from 36 non-consecutive subjects were analyzed. "High-risk" FN criteria included prolonged hospitalization (≥ 7 days), admission to pediatric intensive care unit (PICU) or a microbiology confirmed bacteremia. Patients with "low risk" FN had none of the above. Biomarkers measured during the first 2 days of FN hospitalization were analyzed and correlated with respective clinical outcome.

Results: Of the 89 FN events, 44 (49%) fulfilled pre-defined high-risk criteria and 45 (51%) were low-risk. Procalcitonin level (>0.11 ng/ml) was found to be associated with the high-risk FN outcome with sensitivity of 97%. With an increase in log scale by 1, the odds of being high-risk FN increased twofold. Hs-CRP >100 mg/L had sensitivity of 88% in predicting high-risk FN. The odds of a high-risk FN event increased by approximately 1.8-fold with an increase in the log scale of hs-CRP by 1 (10-fold). In univariate analysis, IL-6, IL-8, and IL-10 were statistically significant and associated with high-risk FN. However, no statistically significant difference was found for IL-1α, sIL-2Ra, IL-3, or TNF-α.

Conclusions: Biomarkers with appropriate critical threshold values may be a useful clinical tool for appropriate risk stratification of children with FN.