Myron Johnson A, Merlini Giampaolo, Sheldon Joanna, Ichihara Kiyoshi
Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC 27410, USA.
Clin Chem Lab Med. 2007;45(3):419-26. doi: 10.1515/CCLM.2007.051.
A large number of circumstances are associated with reduced serum concentrations of transthyretin (TTR), or prealbumin. The most common of these is the acute phase response, which may be due to inflammation, malignancy, trauma, or many other disorders. Some studies have shown a decrease in hospital stay with nutritional therapy based on TTR concentrations, but many recent studies have shown that concentrations of albumin, transferrin, and transthyretin correlate with severity of the underlying disease rather than with anthropometric indicators of hypo- or malnutrition. There are few if any conditions in which the concentration of this protein by itself is more helpful in diagnosis, prognosis, or follow up than are other clinical findings. In the majority of cases, the serum concentration of C-reactive protein is adequate for detection and monitoring of acute phase responses and for prognosis. Although over diagnosis and treatment of presumed protein energy malnutrition is probably not detrimental to most patients, the failure to detect other causes of decreased concentrations (such as serious bacterial infections or malignancy) of the so-called visceral or hepatic proteins could possibly result in increased morbidity or even mortality. In addition to these caveats, assays for TTR have a relatively high level of uncertainty ("imprecision"). Clinical evaluation--history and physical examination--should remain the mainstay of nutritional assessment.
许多情况与血清甲状腺素运载蛋白（TTR）或前白蛋白浓度降低有关。其中最常见的是急性期反应，这可能是由于炎症、恶性肿瘤、创伤或许多其他疾病引起的。一些研究表明，基于TTR浓度的营养治疗可缩短住院时间，但最近许多研究表明，白蛋白、转铁蛋白和甲状腺素运载蛋白的浓度与潜在疾病的严重程度相关，而非与营养不良或营养不足的人体测量指标相关。几乎没有哪种情况表明，该蛋白自身的浓度比其他临床发现对诊断、预后或随访更有帮助。在大多数情况下，血清C反应蛋白浓度足以用于检测和监测急性期反应以及判断预后。虽然对疑似蛋白质能量营养不良的过度诊断和治疗可能对大多数患者无害，但未能检测出所谓的内脏或肝脏蛋白浓度降低的其他原因（如严重细菌感染或恶性肿瘤）可能会导致发病率甚至死亡率增加。除了这些注意事项外，TTR检测的不确定性（“不精确性”）相对较高。临床评估——病史和体格检查——仍应是营养评估的主要依据。
