新生儿急性肾损伤(AKI)是指由于各种原因引起的肾功能在短时间内受到损害，新生儿呈现血容量减少性休克、缺氧、低体温等多种病理状态，血清肌酐水平急性和可逆性增高，伴或不伴尿量减少，水和电解质紊乱、酸碱失衡和代谢废物堆积。AKI表现隐匿，该病新生儿易被临床漏诊。由于AKI新生儿特殊的病理生理特点，使其与成年人AKI患者差异较大，目前临床不断改进的成年人AKI诊断标准，并不适用于临床诊断新生儿AKI。因此，临床需要新型肾损伤生物标志物，对新生儿AKI进行早期预测和诊断。目前可反映肾小管及肾小球损伤，有助于新生儿AKI诊断的新型生物标志物包括：胱抑素C(Cys-C)、中性粒细胞明胶酶相关脂质运载蛋白(NGAL)、肾脏损伤分子(KIM)-1、β2微球蛋白(β2-MG)、α1微球蛋白(α1-MG)、N-乙酰-β-D氨基葡萄糖苷酶(NAG)、肝型脂肪酸结合蛋白(L-FABP)、神经轴突导向因子(Netrin)-1、表皮生长因子(EGF)、白细胞介素(IL)-18、谷胱甘肽-S-转移酶(GST)及β-微量蛋白(BTP)等。在众多预测新生儿AKI的新型生物标志物中，应用相对较多及预测效果较佳的生物标志物是尿、血清Cys-C，尿、血清NGAL和尿KIM-1等，在对AKI新生儿进行早期预测、辅助诊断等方面，均优于血清肌酐及尿量检测。但是，上述新型生病标志物的"正常值"大多受新生儿出生胎龄、体重及其检测时日龄与是否合并全身感染等多种因素影响。这些因素均可降低其预测新生儿AKI的敏感度和特异度。联合检测多种生物标志物预测新生儿AKI，虽然降低了预测特异度，但是可以提高预测敏感度。

Neonatal acute kidney injury (AKI) refers to which kidney function is impaired for a variety of reasons in a short term. The neonates with AKI present a variety of pathological states, such as hypovolemic shock, hypoxia, hypothermia and so on, accompanied by an acute and reversible increment in serum creatinine level associated or not with a reduction in urine output, and resulting in derangements in water-electrolyte balance, acid-base and metabolic waste clearance. The manifestation of AKI is latent, so the neonates with AKI are easily miss diagnosed by clinics. The special pathophysiological characteristics of neonates with AKI are quite different from adult patients with AKI. Currently, the continuously improved diagnostic criteria for adult AKI are not suitable for diagnosis of neonates with AKI. Therefore, new biomarkers of kidney injury are needed for early prediction and auxiliary diagnosis of neonatal AKI. At present, the new biomarkers that can reflect renal tubular, glomerular injury and contribute to diagnosis of neonatal AKI include: cystatin C (Cys-C), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule (KIM)-1, β2-microglobulin (β2-MG), α1-microglobulin (α1-MG), N-acetyl-β-D-glucosaminidase (NAG), liver-type fatty acid-binding protein (L-FABP), axon guidance factor netrin (Netrin)-1, epidermal growth factor (EGF), interleukin (IL)-18, glutathione-S-transferase (GST) and β-trace protein (BTP), etc.. Among many new biomarkers for predicting neonatal AKI, the biomarkers which are more and better applied in clinic are urine or serum Cys-C, urine or serum NGAL, and urine KIM-1. In terms of early prediction and auxiliary diagnosis of neonatal AKI, they perform better than the detection of serum creatinine and urine output. However, their " normal value" is largely affected by many factors, such as gestational age, birth weight, postnatal age and systemic infection of newborns. These factors can reduce the sensitivity and specificity of predicting neonatal AKI. When multiple biomarkers are combined to predict neonatal AKI, the sensitivity can be improved in spite of reduced specificity of prediction.