Dituri F, Buonocore G, Pietravalle A, Naddeo F, Cortesi M, Pasqualetti P, Tataranno M L, Agostino R
Department of Maternal and Child Health, S. Giovanni Calibita Hospital, Fatebenefratelli, Rome.
J Matern Fetal Neonatal Med. 2012 Sep;25(9):1660-3. doi: 10.3109/14767058.2012.657273. Epub 2012 Feb 24.
As the vitamin K content of human milk is low and the newborn infant's stores of vitamin K are small, vitamin K deficiency with hemorrhage in the newborn is a worldwide problem. Proteins Induced by Vitamin K Absence (PIVKA-II) are the inactive under-γ-carboxylated forms of vitamin K-dependent clotting factors and they could be useful in predicting subclinical vitamin K deficiency (VKD).
To demonstrate that PIVKA-II are earlier markers of subclinical VKD than Prothrombin time (PT) in exclusively breast-fed newborns.
A prospective, controlled, randomized study, including 53 term newborns receiving vitamin K prophylaxis (0.5 mg i.m.) at birth, was performed. At 30 days newborns were divided into three groups (G) receiving respectively: 25 μg/die of vitamin K (G I), 12 μg/die (G II) or placebo (G III). PIVKA-II and PT were measured on 30th and 90th days of life.
G III and GII showed a significant increase in PIVKA-II from 30 to 90 days of life respectively from 2.6 to 4.7 (p = 0.001) and from 2.3 to 3.5 (p < 0.001). No significant changes were found in GI. PT showed no significant changes among groups.
PT is a less sensitive marker than PIVKA II. Oral supplementation with 25 μg/die avoids an increase of PIVKA-II. Despite increased PIVKA-II do not mean an impending occurrence of bleeding, they highlight a subclinical VKD and its relative risk.
由于母乳中维生素K含量较低，且新生儿体内维生素K储备较少，新生儿维生素K缺乏伴出血是一个全球性问题。维生素K缺乏诱导蛋白（PIVKA-II）是维生素K依赖凝血因子的无活性低γ-羧化形式，可用于预测亚临床维生素K缺乏（VKD）。
证明在纯母乳喂养的新生儿中，PIVKA-II是比亚临床VKD的凝血酶原时间（PT）更早的标志物。
进行了一项前瞻性、对照、随机研究，纳入53名足月新生儿，这些新生儿在出生时接受了维生素K预防（0.5mg肌肉注射）。在30天时，将新生儿分为三组，分别接受：25μg/天的维生素K（第一组）、12μg/天（第二组）或安慰剂（第三组）。在出生后第30天和第90天测量PIVKA-II和PT。
第三组和第二组在出生后30天至90天PIVKA-II分别从2.6显著增加至4.7（p = 0.001）和从2.3增加至3.�（p < 0.001）。第一组未发现显著变化。各组间PT无显著变化。
PT作为标志物不如PIVKA II敏感。口服补充25μg/天可避免PIVKA-II升高。尽管PIVKA-II升高并不意味着即将发生出血，但它们突出了亚临床VKD及其相对风险。
