Serum high mobility group box protein 1 (HMGB1) levels reflect clinical features of childhood hemophagocytic lymphohistiocytosis.

Purpose: Hemophagocytic lymphohistiocytosis (HLH) is a potentially lethal hyperinflammatory disorder. For further understanding of the pathogenesis of HLH, we examined serum levels of high mobility group box protein 1 (HMGB1) in children with HLH.

Patients and methods: Serum HMGB1 levels were measured in 28 patients with HLH and 6 normal controls using a quantitative enzyme-linked immunosorbent assay. The patients were 21 boys and 7 girls, aged from 10 days to 21 years, with a median age of 8.5 years. The underlying conditions of HLH were infection-associated HLH in 18 patients, malignancy-associated HLH in 7 patients, and genetic HLH in 3 patients. The relations between serum HMGB1 levels and clinical symptoms and laboratory parameters were analyzed.

Results: Serum HMGB1 levels were significantly higher in patients with HLH than in normal controls (median, 6.5 ng/mL, interquartile range, 4.25-13.1). The serial serum HMGB1 levels in one patient fell to reflect the disease activity. Serum HMGB1 levels were significantly higher in patients with disseminated intravascular coagulation (DIC) than in patients without DIC ( p <0.001) and were also significantly higher in patients with central nervous system (CNS) complications than in patients without CNS complications ( p< 0.01). Serum HMGB1 levels were positively correlated with aspartate aminotransferase ( rs   =0.48, p <0.01, Spearman's rank correlation coefficient) and negatively correlated with fibrinogen ( rs   = -0.475, p =0.011) and hemoglobin ( rs   = -0.465, p =0.013).

Conclusion: Serum HMGB1 levels reflect clinical features of childhood HLH. HMGB1 is a potential mediator involved in the pathogenesis and determining the clinical findings of HLH.