Increased Urinary S100B Protein as an Early Indicator of Intraventricular Hemorrhage in Preterm Infants: Correlation with the Grade of Hemorrhage

Abstract

Intraventricular hemorrhage (IVH) is the most common form of cerebral hemorrhage in preterm infants, affecting ∼15–20% (1). Despite accurate postnatal monitoring, IVH is difficult to diagnose during the first 72 h after birth because at this stage, clinical symptoms and radiologic assessment of brain damage may still be silent (2). The availability in these patients of quantitative indicators suggesting subclinical lesions at a time when the monitoring indicators are unable to detect bleeding is therefore important. Furthermore, quantification of the extent of the hemorrhaged lesion could permit the prevention and/or treatment of clinical neurologic damage. S100B is an acidic calcium-binding protein found in the nervous system, where it is concentrated in glial cells (3). The presence of increased S100B in the blood and cerebrospinal fluid (CSF) is a consolidated marker of brain damage in adults and children (4)(5)(6)(7)(8) and has been proposed recently for use in preterm newborns developing IVH (9). We have detected the S100B protein in the urine of preterm newborns under normal conditions and established reference values for the protein at the first urination (10). The present work, extending from the earlier study, investigates urine S100B in preterm newborns developing IVH to offer an indicator for the early detection of IVH. We performed a case-control study on 18 preterm newborns (29–35 weeks of gestation) with IVH in whom urine S100B was measured at first urination (time 0) and at 24 (time 1), 48 (time 2), and 72 h of age (time 3). IVH was diagnosed at 72 h after birth by ultrasound scanning (11): eight infants were classified as grade II (IVH without ventricular dilatation); eight as grade III (IVH with ventricular dilatation); and two as grade IV (IVH with parenchymal lesion). No other ultrasound abnormalities were described at …