Department of Neonatology Obstetrics and Neuroscience, G Gaslini Children's University Hospital, Genoa, Italy.
Clin Chim Acta. 2012 Jan 18;413(1-2):150-3. doi: 10.1016/j.cca.2011.09.011. Epub 2011 Oct 1.
S100B protein is a well-established marker of brain damage. Its importance in urine assessment is the convenience of a collection and sampling procedure that can be repeated without risk for the newborn. Since S100B is mainly eliminated by the kidneys and perinatal asphyxia (PA) is often associated with kidney failure we investigated whether S100B release might be kidney-mediated, thereby modifying the protein's reliability as a brain-damage marker.
We examined a cohort of healthy (n=432) and asphyxiated newborns (n=32) in whom kidney function parameters (blood urea and creatinine concentrations and urine gravity) and urine S100B concentrations were assessed in the first hours after birth. Data were analyzed by multiple logistic regression analysis with S100B as independent variable among a variety of clinical and laboratory monitoring parameters.
S100B urine concentrations were significantly higher (P<0.01) in PA newborns than controls. No significant correlations (P>0.05, for all) between total urine S100B levels and kidney function parameters such as creatinine (r=0.03), urea (r=0.04) and urine gravity (r=0.06) were found. Multiple logistic regression analysis of a series of clinical and laboratory monitoring parameters (odds ratio at sampling: 9.47) with S100B as independent variable showed a positive significant correlation only between S100B levels (P<0.001) and the occurrence of PA.
The present study shows that altered kidney function is not an adverse and/or confounding factor in urine S100B assessment and marks a new step towards the introduction of longitudinal monitoring of brain constituents in clinical practice.
S100B 蛋白是脑损伤的一个成熟标志物。其在尿液评估中的重要性在于采集和取样过程的便利性，且不会对新生儿造成风险。由于 S100B 主要通过肾脏排泄，而围产期窒息（PA）通常与肾功能衰竭有关，我们研究了 S100B 的释放是否可能与肾脏有关，从而改变了该蛋白作为脑损伤标志物的可靠性。
我们对一组健康（n=432）和窒息新生儿（n=32）进行了研究，在出生后最初几小时内评估了肾功能参数（血尿素和肌酐浓度以及尿比重）和尿液 S100B 浓度。通过多元逻辑回归分析，将 S100B 作为独立变量，对各种临床和实验室监测参数进行了分析。
PA 新生儿的尿液 S100B 浓度明显高于对照组（P<0.01）。未发现总尿 S100B 水平与肾功能参数（肌酐 r=0.03，尿素 r=0.04，尿比重 r=0.06）之间存在显著相关性（P>0.05，均为 P>0.05）。以 S100B 为独立变量的一系列临床和实验室监测参数（采样时比值比：9.47）的多元逻辑回归分析显示，S100B 水平（P<0.001）与 PA 的发生之间仅存在显著正相关。
本研究表明，肾功能改变不是尿液 S100B 评估中的不利和/或混杂因素，标志着在临床实践中引入脑成分的纵向监测迈出了新的一步。
