Zamboni Paolo, Izzo Marcello, Tognazzo Silvia, Carandina Sergio, De Palma Massimiliano, Catozzi Linda, Caggiati Alberto, Scapoli Gianluigi, Gemmati D
Vascular Diseases Center, University of Ferrara, 44100 Ferrara, Italy.
Free Radic Biol Med. 2006 May 15;40(10):1869-73. doi: 10.1016/j.freeradbiomed.2006.01.026. Epub 2006 Feb 14.
Chronic venous stasis determines red blood cell extravasation and either dermal hemosiderin deposits or iron-laden phagocytes. Several authors have suspected that iron could play a role in the pathogenesis of venous leg ulcers. They hypothesized that local iron overload could generate free radicals or activate a proteolytic hyperactivity on the part of metalloproteinases (MMPs) or else down-regulate tissue inhibitors of MMPs. However, they were unable to explain why iron deposits, visible in the legs of patients with chronic venous disease (CVD), cause lesions in only some individuals, whereas in others they do not. We hypothesized that such individual differences could be genetically determined and investigated the role of the C282Y and H63D mutations of the HFE gene. C282Y mutation significantly increases the risk of ulcer in primary CVD more than six times (OR = 6.69; 1.45-30.8; p = 0.01). Patients carrying the H63D variant have an earlier age of ulcer onset, by almost 10 years (p > 0.004). The increased risk of skin lesion and the early age of onset of the disease in HFE carriers confirm in a clinical setting that intracellular iron deposits of mutated macrophages have less stability than those of the wild type. We hypothesize that the physiologic iron protective mechanisms are affected by the HFE mutations and should be investigated in all diseases characterized by the combination of iron overload and inflammation.
慢性静脉淤滞会导致红细胞外渗,进而出现真皮含铁血黄素沉积或含铁吞噬细胞。一些作者怀疑铁可能在下肢静脉溃疡的发病机制中起作用。他们推测局部铁过载可能产生自由基,或激活金属蛋白酶(MMPs)的蛋白水解活性增强,抑或下调MMPs的组织抑制剂。然而,他们无法解释为何在慢性静脉疾病(CVD)患者腿部可见的铁沉积仅在部分个体中导致病变,而在其他个体中却不会。我们推测这种个体差异可能由基因决定,并研究了HFE基因的C282Y和H63D突变的作用。C282Y突变使原发性CVD中溃疡风险显著增加超过6倍(OR = 6.69;1.45 - 30.8;p = 0.01)。携带H63D变异的患者溃疡发病年龄更早,几乎早10年(p > 0.004)。HFE基因携带者皮肤病变风险增加以及疾病发病年龄提前,在临床环境中证实了突变巨噬细胞的细胞内铁沉积比野生型的稳定性更低。我们推测生理铁保护机制受HFE突变影响,并且在所有以铁过载和炎症并存为特征的疾病中都应进行研究。