Serum Ferritin Levels in Critically Ill Children With Severe Sepsis and Their Relationship With Mortality: A Prospective Observational Study (FerriPedS Study)

Objectives: To determine the serum ferritin levels, single-center prevalence of hyperferritinemia and its association with mortality in critically ill children with severe sepsis. Methods: This prospective study was conducted in pediatric intensive care unit of a tertiary care teaching hospital in North India over a period of 13 months (June 2023–June 2024), including children 3 months–12 years old with severe sepsis. At admission, blood was collected for estimation of serum ferritin levels. Hyperferritinemia was defined as ferritin levels >500 ng/mL. The primary outcome was to determine the association between serum ferritin and mortality; and secondary outcomes were estimation of serum ferritin levels, single-center prevalence of hyperferritinemia, best cutoff of serum ferritin to predict mortality, and correlation of serum ferritin with severity scores. Results: We enrolled 115 children with a median (interquartile range) age of 3 (1–7) years. The common diagnoses were community-acquired pneumonia (39.1%), scrub typhus (13.9%), CNS infections (10.4%), multisystem viral infection (10.4%), dengue (9.6%), GI sepsis (6.1%), and disseminated Staphylococcal sepsis (4.3%). The median (interquartile range) serum ferritin level was 550 (233–1633) ng/mL and 52% (n = 60) had hyperferritinemia. Nonsurvivors had significantly higher serum ferritin levels compared with survivors 1355 (860–4435) vs. 233 (108–306), P = 0.01. The mortality was significantly higher in children with hyperferritinemia (38.3% vs 16.4%, P = 0.012). The best cutoff of serum ferritin to predict mortality was 705 ng/mL (Area under curve AUC: 0.653, sensitivity and specificity of 63% each, P = 0.011). Children with hyperferritinemia had a longer duration of illness and higher occurrence of organ dysfunction (coagulopathy, hepatic dysfunction, shock, acute respiratory distress syndrome and acute kidney injury). Serum ferritin was positively correlated with pediatric risk of mortality III score ( ρ = 0.342, P = 0.001) pediatric logistic organ dysfucntion-2 score on day 2 ( ρ = 0.204, P = 0.042) and day 5 ( ρ = 0.235, P = 0.046) and vasoactive inotropic score on day 1 ( ρ = 0.305, P = 0.033). Conclusion: Hyperferritinemia was common in critically ill children with severe sepsis and was significantly associated with mortality.