Yapi Houphouët Félix, Ahiboh Hugues, Yayo Eric, Edjeme Angele, Attoungbre-Hauhouot Marie Laure, Allico Joseph Djaman, Monnet Dagui
Laboratoire de pharmacodynamie biochimique, UFR biosciences, Université de Cocody-Abidjan, Abidjan 22, Côte-d'Ivoire.
Sante. 2009 Jan-Mar;19(1):25-8. doi: 10.1684/san.2009.0145.
Throughout the world and particularly in sub-Saharan Africa, deficiencies in trace elements constitute a real public health problem because of the insufficient nutritional quality of food. These trace elements are necessary for many of the body's biochemical reactions. The role of microelements such as vitamin A and zinc has been established in the functioning of the immune system and secretion of inflammatory reaction proteins, but the role of iron in these functions remains to be elucidated. The sample consists of 186 children (3/4) 80 with an iron deficiency and 106 with normal iron status. They range in age from 5 to 15 years and all attend school in the department of Adzope. The study excluded all children with parasites that might affect blood iron, protein and other hematological indicators, in particular, Plasmodium falciparum, Giardia intestinalis, Trichomonas intestinalis, Ascaris lumbricoides, and Ancylostoma. Inflammatory, immune and nutritional proteins were measured by radial immunodiffusion (Mancini's method). Ferritin was measured by a specific immunoenzymatic assay. Hematological indicators were tested by an automatic blood cell counter. Nutritional status was estimated by the weight/height ratio (W/H). This analysis showed that iron deficiency was associated with reduced IgG levels (p < 0.05), although immunoglobulins A and M remained stable (p > 0.05. Iron deficiency was also associated with reduced levels of thyroxine-binding prealbumin (TBPA) and albumin (p < 0.05). Inflammatory proteins did not differ significantly between the two groups (p > 0.05). Furthermore, the prognostic inflammatory and nutritional index (PINI) did not show any inflammatory, vital or nutritional risk, because it was lower than or equal to 2. Finally, malnutrition was not observed in the iron-deficient children: the difference in the weight/height ratio (W/H = 96.58 +/- 2.4%) between the children with iron deficiency and those with normal iron status (98.7 +/- 4.3%) did not differ significantly. The reduced IgG associated with iron deficiency may be attributed to the role that iron plays in the proliferation and maturation of lymphocytes. Reduced iron levels would thus lead to slowing down the hematopoietic mechanism, resulting in a decrease in B lymphocyte production and thus inevitably a reduction in IgG synthesis. The reduction in albumin and TBPA associated with the iron deficiency but in the absence of any sign of malnutrition (W/H > 96%) or inflammatory risk (PINI < 2) in either study group shows that iron may play a dominant role during protein synthesis. Iron deficiency might limit the energy of cellular tissues, leading to a reduction in RNA activity (transcription and translation), which would in turn decrease ribosome activity in tissues and thus reduce amino acid synthesis in cells, resulting in the reduction observed in protein synthesis. The lack of difference between the study groups in inflammatory proteins, notably CRP and alpha1-GPA, indicates that iron deficiency does not appear to be related to an inflammatory process. This study of children without any apparent clinical signs of iron deficiency shows that such a deficiency may be associated with a disruption in protein production. The proteins concerned include IgG, TBPA and albumin. The public authorities should pay particular attention to improving children's diets, especially their micronutrient levels, including for iron, vitamin A and zinc.
在世界各地,尤其是撒哈拉以南非洲地区,由于食物营养质量不足,微量元素缺乏构成了一个切实的公共卫生问题。这些微量元素对人体许多生化反应至关重要。微量元素如维生素A和锌在免疫系统功能及炎症反应蛋白分泌方面的作用已得到证实,但铁在这些功能中的作用仍有待阐明。样本包括186名儿童(3/4),其中80名缺铁,106名铁状态正常。他们年龄在5至15岁之间,都在阿佐佩省上学。该研究排除了所有可能影响血铁、蛋白质及其他血液学指标的寄生虫感染儿童,特别是恶性疟原虫、肠道贾第虫、肠滴虫、蛔虫和钩虫。通过放射免疫扩散法(曼西尼法)测定炎症、免疫和营养蛋白。通过特定免疫酶测定法测定铁蛋白。通过自动血细胞计数器检测血液学指标。通过体重/身高比(W/H)评估营养状况。该分析表明,缺铁与IgG水平降低相关(p < 0.05),尽管免疫球蛋白A和M保持稳定(p > 0.05)。缺铁还与甲状腺素结合前白蛋白(TBPA)和白蛋白水平降低相关(p < 0.05)。两组之间炎症蛋白无显著差异(p > 0.05)。此外,预后炎症和营养指数(PINI)未显示任何炎症、生命或营养风险,因为其低于或等于2。最后,缺铁儿童未观察到营养不良:缺铁儿童与铁状态正常儿童之间的体重/身高比(W/H = 96.58 +/- 2.4%)与(98.7 +/- 4.3%)无显著差异。与缺铁相关的IgG降低可能归因于铁在淋巴细胞增殖和成熟中所起的作用。铁水平降低会导致造血机制减慢,从而导致B淋巴细胞产生减少,进而不可避免地导致IgG合成减少。与缺铁相关的白蛋白和TBPA降低,但两个研究组均无任何营养不良迹象(W/H > 96%)或炎症风险(PINI < 2),这表明铁在蛋白质合成过程中可能起主导作用。缺铁可能会限制细胞组织的能量,导致RNA活性(转录和翻译)降低,这反过来又会降低组织中的核糖体活性,从而减少细胞中氨基酸的合成,导致观察到的蛋白质合成减少。研究组在炎症蛋白方面,尤其是CRP和α1 - GPA方面无差异,这表明缺铁似乎与炎症过程无关。这项对无明显缺铁临床症状儿童的研究表明,这种缺乏可能与蛋白质产生的紊乱有关。相关蛋白质包括IgG、TBPA和白蛋白。公共当局应特别关注改善儿童饮食,尤其是其微量营养素水平,包括铁、维生素A和锌。