The Role of Hemoglobin, Albumin, Lymphocyte, and Platelet Score in Predicting Fulminant Course in Pediatric Acute Myocarditis

INTRODUCTION: Myocarditis is an important cause of morbidity and mortality in children. This study aimed to evaluate whether the hemoglobin, albumin, lymphocyte, and platelet (HALP) score, a recently proposed systemic inflammatory index, can serve as an early predictor of adverse outcomes in pediatric myocarditis.
METHODS: This retrospective study included patients aged >1 month and <18 years who were followed in our clinic between January 1, 2022, and March 1, 2025. Patients were classified as having fulminant myocarditis (requiring inotropic support or extracorporeal membrane oxygenation) or non-fulminant myocarditis. HALP scores measured within the first 6 h of admission were compared between groups.
RESULTS: A total of 155 children (109 boys; median age 12 years) were included, of whom 38 (24.5%) had fulminant myocarditis. Fulminant cases showed significantly lower left ventricular ejection fraction (LVEF) (median 29%, interquartile range [IQR] 24–37) compared with non-fulminant patients (53%, IQR 45–60; p<0.001). N-terminal pro-brain natriuretic peptide levels were markedly higher in the fulminant group (35,596 pg/mL, IQR 18,166–55,419) than in the non-fulminant group (288 pg/mL, IQR 96–1,458; p<0.001). The HALP score was significantly lower in fulminant myocarditis (2.91, IQR 2.18–3.60) compared with non-fulminant cases (5.62, IQR 4.44–7.11; p<0.001). In receiver operating characteristic analysis, HALP demonstrated excellent discrimination for fulminant myocarditis (area under the curve 0.926; 95% confidence interval 0.874–0.972), with an optimal cut-off of <3.78 (sensitivity 85%, specificity 90%).
DISCUSSION AND CONCLUSION: Lower HALP scores and reduced LVEF were independent predictors of fulminant myocarditis. HALP, an easily calculated biomarker derived from routine laboratory parameters, may support early identification of children at risk for a fulminant course.

Keywords: Albumin, lymphocyte and platelet score, biomarker, hemoglobin, myocarditis, pediatric.