Thuret I
Service d'onco-hématologie pédíatrique, CHU Timone Enfants, centre de référence des thalassémies, 264, rue Saint-Pierre, 13005 Marseille, France.
Arch Pediatr. 2017 May;24(5S):5S6-5S13. doi: 10.1016/S0929-693X(17)24003-2.
Measurement of serum ferritin (SF) is currently the laboratory test recommended for diagnosing iron deficiency. In the absence of an associated disease, a low SF value is an early and highly specific indicator of iron deficiency. The WHO criteria proposed to define depleted storage iron are 12μg/L for children under 5 years and 15μg/L for those over 5 years. A higher threshold of 30μg/L is used in the presence of infection or inflammation. Iron deficiency anemia, with typical low mean corpuscular volume and mean corpuscular hemoglobin, is only present at the end stage of iron deficiency. Other diagnostic tests for iron deficiency including iron parameters (low serum iron, increased total iron-binding capacity, low transferrin saturation) and erythrocyte traits (low mean corpuscular volume, increased zinc protoporphyrin) provide little additional diagnostic value over SF. In children, serum soluble transferrin receptor (sTfR) has been reported to be a sensitive indicator of iron deficiency and is relatively unaffected by inflammation. On the other hand, sTfR is directly related to extent of erythroid activity and not commonly used in clinical practice. In population surveys, approaches based on combinations of markers have been explored to improve the specificity and sensitivity of diagnostic. In addition to Hb value determination, a combination of parameters (among transferrin saturation, zinc protoporphyrin, mean corpuscular volume or serum ferritin) was generally used to assess iron deficiency. More recently sTfR/ ferritin index were evaluated, sTfR in conjunction with SF allowing to better distinguishing iron deficiency from inflammatory anemia. Also, hepcidin measurements appeared an interesting marker for diagnosing iron deficiency and identifying individuals in need of iron supplementation in populations where inflammatory or infectious diseases are frequently encountered. Reticulocyte Hb content (CHr) determination is an early parameter of iron deficiency erythropoiesis. CHr can be measured with several automated hematology analyzers and so, used for individual's iron status assessment. In addition to Hb concentration determination, individual's iron status is commonly assessed in the pediatric clinical practice by the SF measurement accompanied by the determination of C-reactive protein for detection of a simultaneous acute infection and/or inflammation.
血清铁蛋白（SF）测定是目前推荐用于诊断缺铁的实验室检查。在无相关疾病的情况下，低SF值是缺铁的早期且高度特异性指标。世界卫生组织提出的定义储存铁耗竭的标准是5岁以下儿童为12μg/L，5岁以上儿童为15μg/L。在存在感染或炎症时，使用30μg/L的更高阈值。缺铁性贫血伴有典型的低平均红细胞体积和平均红细胞血红蛋白，仅出现在缺铁的末期。其他缺铁诊断试验，包括铁参数（低血清铁、总铁结合力增加、转铁蛋白饱和度低）和红细胞特征（低平均红细胞体积、锌原卟啉增加），相对于SF几乎没有额外的诊断价值。在儿童中，血清可溶性转铁蛋白受体（sTfR）据报道是缺铁的敏感指标，且相对不受炎症影响。另一方面，sTfR与红系活性程度直接相关，在临床实践中不常用。在人群调查中，已探索基于标志物组合的方法来提高诊断的特异性和敏感性。除了测定血红蛋白值外，通常还使用参数组合（转铁蛋白饱和度、锌原卟啉、平均红细胞体积或血清铁蛋白之间）来评估缺铁情况。最近对sTfR/铁蛋白指数进行了评估，sTfR与SF结合可更好地区分缺铁性贫血与炎症性贫血。此外，在经常遇到炎症或感染性疾病的人群中，铁调素测量似乎是诊断缺铁和识别需要补充铁剂个体的一个有趣标志物。网织红细胞血红蛋白含量（CHr）测定是缺铁性红细胞生成的早期参数。CHr可通过多种自动血液分析仪进行测量，因此可用于个体铁状态评估。除了测定血红蛋白浓度外，在儿科临床实践中，个体的铁状态通常通过SF测量并同时测定C反应蛋白以检测同时存在的急性感染和/或炎症来评估。
