Gutteridge J M, Quinlan G J, Evans T W
Department of Anaesthesia and Intensive Care, Royal Brompton Hospital, London.
Thorax. 1994 Jul;49(7):707-10. doi: 10.1136/thx.49.7.707.
A retrospective study was conducted to evaluate iron status in plasma samples collected from five patients with the adult respiratory distress syndrome (ARDS) who had bleomycin detectable iron in at least one sample. Ten patients with ARDS with no evidence of bleomycin detectable iron and 10 healthy individuals served as controls.
Evidence of iron overload was established by measuring the percentage saturation of plasma transferrin. In each case the bleomycin assay for redox active, chelatable iron was used to measure plasma levels of non-transferrin bound iron in the low micromolar range; assays for total plasma iron and transferrin were performed to establish a diagnosis of transient iron overload. The effect of this on the ability of transferrin to act as a plasma antioxidant was assessed using two different assay systems.
The five patients with evidence of transient iron overload (mortality 4/5) represented 33% of the total population of patients with ARDS (mortality 5/10) managed by the unit during the study period. All had low molecular mass iron detectable in their plasma and had clinical and biochemical evidence of multiorgan system failure as well as liver impairment. Compared with the ARDS and normal control populations, transferrin and albumin levels were low and the former failed to act as a plasma antioxidant in preventing free radical mediated damage to detector molecules.
Patients with ARDS are thought to be under severe oxidative stress from their disease and from treatment with high inspired oxygen concentrations. A subgroup of patients with ARDS has been identified who displayed evidence of transient iron overload as a result of which their plasma iron binding antioxidant protection was greatly compromised. This finding must be considered a serious additional risk factor for oxidative stress.
进行了一项回顾性研究，以评估从五名患有成人呼吸窘迫综合征（ARDS）且至少在一份样本中检测到博来霉素可检测铁的患者采集的血浆样本中的铁状态。十名无博来霉素可检测铁证据的ARDS患者和十名健康个体作为对照。
通过测量血浆转铁蛋白的饱和百分比来确定铁过载的证据。在每种情况下，使用针对氧化还原活性、可螯合铁的博来霉素测定法来测量低微摩尔范围内非转铁蛋白结合铁的血浆水平；进行总血浆铁和转铁蛋白测定以诊断短暂性铁过载。使用两种不同的测定系统评估其对转铁蛋白作为血浆抗氧化剂能力的影响。
五名有短暂性铁过载证据的患者（死亡率4/5）占研究期间该科室管理的ARDS患者总数（死亡率5/10）的33%。所有患者血浆中均可检测到低分子量铁，并有多器官系统衰竭及肝功能损害的临床和生化证据。与ARDS患者和正常对照人群相比，转铁蛋白和白蛋白水平较低，且前者在预防自由基介导的对检测分子的损伤方面未能起到血浆抗氧化剂的作用。
ARDS患者被认为因其疾病以及高吸入氧浓度治疗而处于严重的氧化应激状态。已确定一组ARDS患者表现出短暂性铁过载的证据，其血浆铁结合抗氧化保护因此受到极大损害。这一发现必须被视为氧化应激的一个严重附加风险因素。
