Ramsay Jessica, Morton Jacob, Norris Marie, Kanungo Shibani
Department of Pediatric and Adolescent Medicine, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA.
Biochemical Genetics & Nutrition, Seattle Children's Hospital, Seattle, Washington, USA.
Ann Transl Med. 2018 Dec;6(24):472. doi: 10.21037/atm.2018.12.39.
Organic acids (OAs) are intermediary products of several amino acid catabolism or degradation via multiple biochemical pathways for energy production. Vitamins or co-factors are often quintessential elements in such degradation pathways and OA metabolism. OAs that result from enzyme defects in these pathways can be identified in body fluids utilizing gas chromatography-mass spectrometry techniques (GC/MS). OAs are silent contributor to acid base imbalance and can affect nitrogen balance and recycling. Since OA production occurs in distal steps of a specific amino acid catabolism, offending amino acid accumulation is not characteristic. OA disorders as inborn errors of metabolism (IEM) are included in differential diagnosis of metabolic acidosis, as the common mnemonic MUDPILES taught in medical schools. High anion gap metabolic acidosis with hyperammonemia is a characteristic OA biochemical finding. VOMIT (valine, odd chain fatty acids, methionine, isoleucine, and threonine) is a smart acronym and a common clinical presentation of OA disorders and can present as early life-threatening illness, prior to Newborn Screening results availability. Easy identification and available medical formula make the field of metabolic nutrition vital for management of OA disorders. Treatment strategies also involve cofactor/vitamin utilization to aid specific pathways and disorder management. Optimal metabolic control and regular monitoring is key to long-term management and prevention of morbidity, disability and mortality. Prompt utilization of acute illness protocol (AIP) or emergency protocol and disorder specific education of family members or caregivers, primary care physicians and local emergency health care facilities; cautiously addressing common childhood illnesses in patients with OA disorders, can help avoid poor short- and long-term morbidity, disability and mortality outcomes.
有机酸(OAs)是几种氨基酸通过多种生物化学途径进行分解代谢或降解以产生能量的中间产物。维生素或辅助因子通常是此类降解途径和OA代谢中的关键要素。利用气相色谱 - 质谱技术(GC/MS)可在体液中识别出这些途径中因酶缺陷而产生的OA。OA是酸碱失衡的隐性因素,会影响氮平衡和再循环。由于OA产生于特定氨基酸分解代谢的远端步骤,因此不会出现相关氨基酸积累的特征。作为先天性代谢缺陷(IEM)的OA紊乱包含在代谢性酸中毒的鉴别诊断中,就像医学院所教授的常见记忆口诀MUDPILES那样。伴有高氨血症的高阴离子间隙代谢性酸中毒是OA的典型生化表现。VOMIT(缬氨酸、奇数链脂肪酸、蛋氨酸、异亮氨酸和苏氨酸)是一个巧妙的首字母缩写词,也是OA紊乱的常见临床表现,在新生儿筛查结果出来之前,可能表现为早期危及生命的疾病。易于识别和现有的医学配方使代谢营养领域对于OA紊乱的管理至关重要。治疗策略还包括利用辅助因子/维生素来辅助特定途径和疾病管理。最佳的代谢控制和定期监测是长期管理以及预防发病、残疾和死亡的关键。及时采用急性疾病方案(AIP)或紧急方案,并对家庭成员或护理人员、初级保健医生和当地紧急医疗保健机构进行特定疾病教育;谨慎处理OA紊乱患者的常见儿童疾病,有助于避免不良的短期和长期发病、残疾和死亡结果。