Shenai J P, Rush M G, Stahlman M T, Chytil F
Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee.
J Pediatr. 1990 Apr;116(4):607-14. doi: 10.1016/s0022-3476(05)81614-2.
We hypothesized that changes in plasma retinol-binding protein (RBP) concentration in response to vitamin A administration might be useful for evaluating vitamin A status of very low birth weight infants susceptible to bronchopulmonary dysplasia. We prospectively studied 24 consecutively admitted neonates (birth weight less than 1350 gm, gestational age less than 31 weeks, ventilator dependent for greater than 24 hours after birth), who were eligible to receive 2000 IU supplemental vitamin A by intramuscular injection on postnatal day 1 and on alternate days thereafter for 28 days. In addition to serial assessment of vitamin A status, we measured plasma RBP just before and 1, 3, and 6 hours after an intramuscular injection of vitamin A (2000 IU/kg retinyl palmitate) on days 1 and 28. The percent increase in plasma RBP (delta-RBP) was high (mean +/- SD: 61 +/- 37%) and plasma vitamin A and RBP values were low on day 1, indicative of vitamin A deficiency. Supplemental vitamin A improved vitamin A status of all infants as shown by low delta-RBP (mean +/- SD: 8 +/- 9%) and normal plasma vitamin A and RBP values on day 28. Bronchopulmonary dysplasia was diagnosed in 12 of 24 infants. Infants with bronchopulmonary dysplasia had a higher mean (+/- SD) delta-RBP on day 28 than those without bronchopulmonary dysplasia (13 +/- 10% vs 3 +/- 3%, p less than 0.01), indicative of persistence of low vitamin A status in infants with lung disease despite supplementation. We conclude that the plasma RBP response to vitamin A is a useful indicator of vitamin A status in very low birth weight infants. Although vitamin A supplementation at the dosage used in this study normalizes conventional plasma indexes of vitamin A in very low birth weight infants, the plasma RBP response to vitamin A may continue to reflect persistence of low vitamin A status in the more immature infants with significant lung disease. We suggest that the plasma RBP response to vitamin A may be a useful functional test in such infants.
我们推测，给予维生素A后血浆视黄醇结合蛋白（RBP）浓度的变化可能有助于评估易患支气管肺发育不良的极低出生体重儿的维生素A状态。我们前瞻性地研究了24例连续入院的新生儿（出生体重小于1350克，胎龄小于31周，出生后依赖呼吸机超过24小时），这些新生儿符合在出生后第1天及此后每隔一天肌肉注射2000 IU补充维生素A，共28天的条件。除了对维生素A状态进行系列评估外，我们在第1天和第28天肌肉注射维生素A（2000 IU/kg棕榈酸视黄酯）前以及注射后1、3和6小时测量血浆RBP。第1天时血浆RBP的百分比增加值（Δ-RBP）很高（均值±标准差：61±37%），血浆维生素A和RBP值很低，表明存在维生素A缺乏。补充维生素A改善了所有婴儿的维生素A状态，如第28天时低Δ-RBP（均值±标准差：8±9%）以及正常的血浆维生素A和RBP值所示。24例婴儿中有12例被诊断为支气管肺发育不良。患有支气管肺发育不良的婴儿在第28天时的平均（±标准差）Δ-RBP高于未患支气管肺发育不良的婴儿（13±10%对3±3%，p<0.01），这表明尽管进行了补充，但患有肺部疾病的婴儿维生素A状态持续较低。我们得出结论，血浆RBP对维生素A的反应是极低出生体重儿维生素A状态的一个有用指标。尽管本研究中使用的剂量的维生素A补充使极低出生体重儿常规血浆维生素A指标正常化，但血浆RBP对维生素A的反应可能继续反映患有严重肺部疾病的更不成熟婴儿中维生素A状态持续较低的情况。我们建议血浆RBP对维生素A的反应可能是此类婴儿的一种有用的功能测试。
