Combinations of host biomarkers predict mortality among Ugandan children with severe malaria: a retrospective case-control study

• Published in: PloS one 2011-02, Vol.6 (2), p.e17440-e17440
• Main Authors: Erdman, Laura K, Dhabangi, Aggrey, Musoke, Charles, Conroy, Andrea L, Hawkes, Michael, Higgins, Sarah, Rajwans, Nimerta, Wolofsky, Kayla T, Streiner, David L, Liles, W Conrad, Cserti-Gazdewich, Christine M, Kain, Kevin C
• Format: Article
• Language: English
• Subjects: Adults; Analysis; Anemia; Angiopoietin; Arthritis; Bioavailability; Bioindicators; Biological markers; Biological response modifiers; Biology; Biomarkers; Biomarkers - analysis; Bone marrow; Brain research; C-reactive protein; Case-Control Studies; Cell adhesion; Cell adhesion & migration; Child; Child, Preschool; Children; Chronic illnesses; Combinatorial analysis; Cytokines; Death; Developing countries; Development and progression; Endoglin; Endothelium; Enzyme-linked immunosorbent assay; Ethics; Fatalities; Female; Health care networks; Hospitals; Humans; Infant; Infections; Infectious diseases; Inflammation; Intercellular adhesion molecule 1; Interferon; IP-10 protein; Laboratories; LDCs; Ligands; Malaria; Malaria - classification; Malaria - diagnosis; Malaria - mortality; Malaria - pathology; Male; Mathematical models; Medicine; Mortality; Myeloid cells; P-selectin; Pathogenesis; Pediatrics; Plasmodium falciparum; Procalcitonin; Prognosis; Protein-tyrosine kinase; Retrospective Studies; Sensitivity; Sensitivity analysis; Severity of Illness Index; Standard error; Survival Analysis; Tropical diseases; Tyrosine; Uganda; Vector-borne diseases; Von Willebrand factor
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0017440

Severe malaria is a leading cause of childhood mortality in Africa. However, at presentation, it is difficult to predict which children with severe malaria are at greatest risk of death. Dysregulated host inflammatory responses and endothelial activation play central roles in severe malaria pathogenesis. We hypothesized that biomarkers of these processes would accurately predict outcome among children with severe malaria. Plasma was obtained from children with uncomplicated malaria (n = 53), cerebral malaria (n = 44) and severe malarial anemia (n = 59) at time of presentation to hospital in Kampala, Uganda. Levels of angiopoietin-2, von Willebrand Factor (vWF), vWF propeptide, soluble P-selectin, soluble intercellular adhesion molecule-1 (ICAM-1), soluble endoglin, soluble FMS-like tyrosine kinase-1 (Flt-1), soluble Tie-2, C-reactive protein, procalcitonin, 10 kDa interferon gamma-induced protein (IP-10), and soluble triggering receptor expressed on myeloid cells-1 (TREM-1) were determined by ELISA. Receiver operating characteristic (ROC) curve analysis was used to assess predictive accuracy of individual biomarkers. Six biomarkers (angiopoietin-2, soluble ICAM-1, soluble Flt-1, procalcitonin, IP-10, soluble TREM-1) discriminated well between children who survived severe malaria infection and those who subsequently died (area under ROC curve>0.7). Combinational approaches were applied in an attempt to improve accuracy. A biomarker score was developed based on dichotomization and summation of the six biomarkers, resulting in 95.7% (95% CI: 78.1-99.9) sensitivity and 88.8% (79.7-94.7) specificity for predicting death. Similar predictive accuracy was achieved with models comprised of 3 biomarkers. Classification tree analysis generated a 3-marker model with 100% sensitivity and 92.5% specificity (cross-validated misclassification rate: 15.4%, standard error 4.9%). We identified novel host biomarkers of pediatric severe and fatal malaria (soluble TREM-1 and soluble Flt-1) and generated simple biomarker combinations that accurately predicted death in an African pediatric population. While requiring validation in further studies, these results suggest the utility of combinatorial biomarker strategies as prognostic tests for severe malaria.