Urinary and serum levels of high mobility group box 1.

Background: High mobility group box 1 (HMGB-1) has been extensively studied in adults and to a certain extent in neonates as well. Clinical examination of neonates, especially unwell neonates soon after birth, should be minimally invasive.

Objective: This study aimed to investigate whether the urinary HMGB-1 level is comparable to the serum HMGB-1 level in neonates.

Methods: In all, 87 neonates (37.5 ± 2.9 weeks of gestation and a mean birth weight of 2588 ± 649 g) were enrolled. Of these, 53 were males and 34 were females. The umbilical cord blood and the first or second spontaneous voiding urine samples were stored, and the HMGB-1 level in the samples was measured.

Results: HMGB-1 was detected in all urinary samples. In these samples, we found acetylated HMGB-1 and may be devoid of nine residues at the N-terminal amino acid sequence. There was a significant correlation between the serum HMGB-1 level and urinary HMGB-1 level (r = 0.73, p < 0.001). Urinary HMGB1 levels in fetal neonatal asphyxia were significantly higher than those in healthy controls (p = 0.09).

Conclusion: Urinary excretion may be one of the metabolic pathways of HMGB-1. The urinary HMGB-1 level may be comparable to the serum HMGB-1 level in the early neonatal period.