Amino Acid Profiles in Patients with Urea Cycle Disorders at Admission to Hospital due to Metabolic Decompensation
Amino Acid Profiles in Patients with Urea Cycle Disorders at Admission to Hospital due to Metabolic Decompensation
复制标题
DOI：
10.1007/8904_2012_186
复制
发表时间：
2013-01-01
期刊：
影响因子：
--
通讯作者：
Boneh, A.
中科院分区：
文献类型：
--
作者：
Rodney, S.;Boneh, A.
尿素循环障碍(UCDs)是由氨解毒途径的遗传缺陷引起的，导致高氨血症和脑病。这项研究的目的是回答这样一个问题，“一名已知的UCD患者在急性代谢失代偿期出现高氨血症的血浆氨基酸谱可能是什么”，以支持明智的管理决策。我们分析了墨尔本皇家儿童医院28年来所有UCD患者急性入院期间血氨水平和氨基酸谱的结果，这些结果是同时或在30分钟内彼此相隔的。来自14名患者的96个入院样本(分别为79、9和8个非处方药、CPS和ASS缺陷入院)符合这些标准。用柱后吲哚衍生化的离子交换层析测定氨基酸水平，并与年龄相关的参考范围进行解释。所有被测必需氨基酸的血浆浓度几乎在所有样本中都处于低水平或低正常水平。OTC缺乏症患者血浆低支链氨基酸与其他必需氨基酸呈显著正相关，氨和苯丙氨酸/酪氨酸(Phe/Tyr)比值呈负相关，谷氨酰胺与Phe/Tyr比值呈负相关，提示蛋白质缺乏。这些结果挑战了目前UCDS急性失代偿期间停止蛋白质摄入的指导方针。应考虑在这些时间补充必需氨基酸(特别是支链氨基酸)。
Urea cycle disorders (UCDs) result from inherited defects in the ammonia detoxification pathway, leading to episodes of hyperammonaemia and encephalopathy. The purpose of this study was to answer the question, "what is the likely plasma amino acid profile of a patient known to have a UCD presenting with hyperammonaemia during acute metabolic decompensation", in order to support informed decisions regarding management.We analysed the results of plasma ammonia levels and amino acid profiles taken simultaneously or within 30 min of each other during acute admissions of all patients with a UCD at the Royal Children's Hospital, Melbourne, over 28 years. Samples from 96 admissions (79, 9 and 8 admissions for OTC, CPS and ASS deficiencies, respectively) from 14 patients fulfilled these criteria. Amino acid levels were measured by ion exchange chromatography with post-column ninhydrin derivatisation and interpreted in relation to age-related reference ranges.Plasma concentrations of all measured essential amino acids were low or low-normal in almost all samples. There was a strong positive correlation between low plasma branched-chain amino acids and other essential amino acids, and a negative correlation between ammonia and phenylalanine to tyrosine (Phe:Tyr) ratio in patients with OTC deficiency, and between glutamine and Phe: Tyr ratio in all patients, indicating protein deficiency.Conclusion: At admission, protein deficiency is common in patients with a UCD with hyperammonaemia. These results challenge the current guideline of stopping protein intake during acute decompensation in UCDs. Supplementation with essential amino acids (particularly branched-chain amino acids) at these times should be considered.