Zamboni Paolo, Tognazzo Silvia, Izzo Marcello, Pancaldi Francesca, Scapoli Gian L, Liboni Alberto, Gemmati Donato
Inter-Departmental Vascular Disease Center, University of Ferrara, Italy.
J Vasc Surg. 2005 Aug;42(2):309-14. doi: 10.1016/j.jvs.2005.04.003.
Chronic venous disease (CVD) is the most common vascular disorder, progressing in approximately 10% of cases toward chronic venous leg ulceration, whereas the hemochromatosis gene (HFE) C282Y mutation is the most common recognized genetic defect in iron metabolism. Because CVD leads to local iron overload in the affected legs, we investigated whether two common HFE mutations could increase the risk of chronic venous leg ulceration.
This was a case-control study at the Vascular Diseases Center, University of Ferrara, Italy. From a cohort of 980 consecutive patients affected by severe CVD (CEAP clinical classes C4 to C6) we selected 238 cases with the exclusion of any other comorbidity factor potentially involved in wound etiology (group A). They were subdivided into group B, including 137 patients with ulcer (classes C5 and C6: 98 primary and 39 postthrombotic cases), and group C, including 101 cases with no skin lesions (class C4). They were completely matched for sex, age, and geographic origin with 280 healthy controls (group D). A total of 518 subjects were polymerase chain reaction genotyped for HFE mutations (C282Y and H63D). We assessed the risk of ulceration by comparing the prevalence of ulcer in homogenous cases with and without the HFE variants. Other main outcome measures were the sensitivity, specificity, and predictive values of the genetic test in CVD cases.
C282Y mutation significantly increases the risk of ulcer in primary CVD by almost seven times (odds ratio, 6.69; 95% confidence interval, 1.45-30.8; P = .01). Application of the HFE test in primary CVD demonstrated increased specificity and positive predictive values (98% and 86%, respectively), with negligible sensitivity and negative predictive values.
The overlap of primary CVD and the C282Y mutation consistently increases the risk of developing venous leg ulceration. These data, which have been confirmed in other clinical settings, suggest new strategies for preventing and treating primary CVD.
The number of patients affected by primary CVD is so great that the vast majority of ulcers are also related to this common problem. On the other hand, there is not a reliable way for identifying in advance, from the broad base of primary CVD patients (20-40% of the general population), the high risk minority (10% of primary CVD cases) who will develop a venous ulcer. In such cases, a simple C282Y blood genetic test demonstrated an elevated specificity in predicting ulcer development (98%, CI 95%, 92.8-99.7). The genetic test could be applied starting from the C2 class, varicose veins, the most common situation observed in clinical practice. In perspective, the presence of the C282Y mutation would strengthen the indications and priorities for surgical correction of superficial venous insufficiency.
慢性静脉疾病(CVD)是最常见的血管疾病,约10%的病例会进展为慢性下肢静脉溃疡,而血色素沉着症基因(HFE)C282Y突变是铁代谢中最常见的公认遗传缺陷。由于CVD会导致患侧腿部局部铁过载,我们研究了两种常见的HFE突变是否会增加慢性下肢静脉溃疡的风险。
这是一项在意大利费拉拉大学血管疾病中心进行的病例对照研究。从980例连续的重度CVD患者(CEAP临床分级C4至C6)队列中,我们选择了238例排除了任何其他可能与伤口病因相关的合并症因素的患者(A组)。他们被分为B组,包括137例溃疡患者(C5和C6级:98例原发性和39例血栓后病例),以及C组,包括101例无皮肤病变的病例(C4级)。他们在性别、年龄和地理来源上与280名健康对照(D组)完全匹配。总共518名受试者进行了HFE突变(C282Y和H63D)的聚合酶链反应基因分型。我们通过比较有和没有HFE变异的同质病例中溃疡的患病率来评估溃疡风险。其他主要结局指标是基因检测在CVD病例中的敏感性、特异性和预测值。
C282Y突变使原发性CVD患者发生溃疡的风险显著增加近7倍(优势比,6.69;95%置信区间,1.45 - 30.8;P = 0.01)。HFE检测应用于原发性CVD时显示特异性和阳性预测值增加(分别为98%和86%),而敏感性和阴性预测值可忽略不计。
原发性CVD与C282Y突变的重叠持续增加发生下肢静脉溃疡的风险。这些数据在其他临床环境中得到了证实,为预防和治疗原发性CVD提出了新策略。
受原发性CVD影响的患者数量众多,以至于绝大多数溃疡也与这个常见问题相关。另一方面,从大量的原发性CVD患者(占普通人群的20 - 40%)中提前识别出将发生静脉溃疡的高风险少数群体(原发性CVD病例的10%),目前还没有可靠的方法。在这种情况下,简单的C282Y血液基因检测在预测溃疡发生方面显示出较高的特异性(98%,95%置信区间,92.8 - 99.7)。基因检测可以从C2级静脉曲张开始应用,这是临床实践中最常见的情况。从长远来看,C282Y突变的存在将加强浅表静脉功能不全手术矫正的指征和优先级。