Pediatric Surgery Department, Hospital Universitario de Navarra, Calle Irunlarrea 3, 31008, Pamplona, Navarra, Spain.
Department of Preventive Medicine and Public Health, School of Medicine, University de Navarra, Pamplona, Spain.
Pediatr Surg Int. 2022 Nov;38(11):1569-1576. doi: 10.1007/s00383-022-05197-w. Epub 2022 Aug 16.
NGAL has recently been studied as a biomarker in the diagnostic context of pediatric acute appendicitis (PAA), although existing series are scarce and have limited sample sizes.
A prospective observational study was designed to validate serum NGAL as a diagnostic tool in PAA. This study included 215 patients, divided into 3 groups: (1) patients undergoing major outpatient surgery (n = 63), (2) patients with non-surgical abdominal pain in whom a diagnosis of PAA was excluded (n = 53) and (3) patients with a confirmed diagnosis of PAA (n = 99). Patients in group 3 were divided into complicated or uncomplicated appendicitis. In 201 patients, a serum sample was obtained at the time of diagnosis and NGAL concentration was determined by ELISA. The Kolmogorov-Smirnov test was used to assess normality. Comparative statistical analyses were performed using the Mann-Whitney U test, the Kruskal-Wallis test and the Fisher's exact test. To calculate the discriminative ability of the molecule, the area under the receiver-operating characteristic curves (AUC) was calculated. A p value < 0.05 established statistical significance.
Median (interquartile range) of serum NGAL values were 38.88 (27.15-48.04) ng/mL (group 1), 51.84 (37.33-69.80) ng/mL (group 2) and 65.06 (50.50-86.60) ng/mL (group 3). The AUC (group 2 vs 3) was 0.642 (95% CI 0.542-0.741) (p < 0.001) and the best cutoff point was found to be at 40.97 ng/mL, with a sensitivity of 89% and a specificity of 34.6%. No statistically significant differences in serum NGAL values were found between patients with uncomplicated PAA and those with complicated PAA.
This prospective validation study with a large sample size confirms that the diagnostic yield of NGAL in the context of PAA is only moderate, and therefore, it should not be used as a unique diagnostic tool. Furthermore, NGAL is not a valid biomarker to discern between uncomplicated and complicated PAA.
中性粒细胞明胶酶相关脂质运载蛋白（NGAL）最近被研究作为儿科急性阑尾炎（PAA）诊断中的生物标志物，尽管现有的研究系列很少且样本量有限。
设计了一项前瞻性观察性研究，以验证血清 NGAL 作为 PAA 的诊断工具。这项研究纳入了 215 例患者，分为 3 组：（1）行择期大手术的患者（n=63），（2）非手术性腹痛但排除 PAA 诊断的患者（n=53）和（3）确诊为 PAA 的患者（n=99）。第 3 组患者进一步分为伴有或不伴有复杂性阑尾炎的患者。在 201 例患者中，在诊断时获得血清样本，通过 ELISA 测定 NGAL 浓度。采用 Kolmogorov-Smirnov 检验评估正态性。采用 Mann-Whitney U 检验、Kruskal-Wallis 检验和 Fisher 确切检验进行比较性统计分析。计算分子的鉴别能力，计算受试者工作特征曲线下面积（AUC）。p 值<0.05 表示具有统计学意义。
血清 NGAL 值的中位数（四分位距）分别为 38.88（27.15-48.04）ng/mL（第 1 组）、51.84（37.33-69.80）ng/mL（第 2 组）和 65.06（50.50-86.60）ng/mL（第 3 组）。AUC（第 2 组 vs 第 3 组）为 0.642（95%CI 0.542-0.741）（p<0.001），最佳截断值为 40.97ng/mL，灵敏度为 89%，特异性为 34.6%。无并发症 PAA 患者和伴有并发症 PAA 患者的血清 NGAL 值无统计学差异。
这项具有大样本量的前瞻性验证研究证实，NGAL 在 PAA 中的诊断效果仅为中等，因此不应将其作为唯一的诊断工具。此外，NGAL 不是区分简单性和复杂性 PAA 的有效生物标志物。
