Association of Serum Ferritin and Lactate Dehydrogenase with Severity of Dengue in Hospitalised Children: A Prospective Observational Study

Abstract

Background: Early recognition of severe dengue in children remains clinically important, particularly in endemic settings where deterioration may occur during the critical phase. Serum ferritin and lactate dehydrogenase (LDH) are accessible laboratory markers potentially associated with hyper-inflammation and tissue injury.

Objectives: To assess the association of serum ferritin and LDH with severe dengue in hospitalised children, and to compare their performance at the predefined laboratory thresholds.

Methods: This prospective observational study included 100 children aged 1-12 years with laboratory confirmed dengue admitted to the Department of Paediatrics, PSP Medical College Hospital and Research Institute, Kancheepuram District, Tamil Nadu, during 2025. Serum ferritin and LDH were measured on admission between day 3 and day 7 of illness. Severe dengue status was compared with biomarker categories and selected clinical findings.

Results: Twenty children (20.0%) developed severe dengue. Ferritin was 300 ng/mL or higher in 18/20 severe cases and 1/80 non-severe cases, while LDH was 250 U/L or higher in 19/20 severe cases and 5/80 non-severe cases. Concurrent elevation of both markers occurred in 18/20 severe cases and in none of the non-severe cases. Elevated ferritin, elevated LDH and combined elevation were each significantly associated with severe dengue (all p<0.001). Ferritin elevation had sensitivity 90.0% and specificity 98.8%; LDH elevation had sensitivity 95.0% and specificity 93.8%; combined elevation retained sensitivity of 90.0% with specificity of 100.0%.

Conclusion: Serum ferritin and LDH were strongly associated with severe dengue in this paediatric hospital cohort. Their combined elevation may aid early risk stratification, although validation in larger multicentre cohorts is needed before adopting fixed thresholds for prediction.