Capaccio Pasquale, Cuccarini Valeria, Ottaviani Francesco, Fracchiolla Nicola Stefano, Bossi Anna, Pignataro Lorenzo
Department of Otorhinolaryngological and Ophthalmological Sciences, University of Milan, Fondazione IRCCS Policlinico, Mangiagalli e Regina Elena, Milan, Italy.
Ann Otol Rhinol Laryngol. 2009 Mar;118(3):205-10. doi: 10.1177/000348940911800308.
Impaired cochlear perfusion seems to be an important event in sudden sensorineural hearing loss. Prothrombotic gene mutations have been related to vascular disorders and sudden hearing loss. We assessed the prothrombotic risk in 10 patients with sudden sensorineural hearing loss who had previously experienced cardiovascular events to support its vascular pathogenesis.
Ten patients underwent hematologic tests (MTHFR C677T/A1298C, prothrombin G20210A, platelet GlyIIIaA1/A2, and V Leiden G1691A genotyping; fibrinogenemia; cholesterolemia: homocysteinemia; folatemia). The results were compared with those of 100 previously investigated patients with sudden hearing loss alone and those of 200 healthy controls. DNA was isolated from peripheral blood leukocytes, and the gene mutations were investigated by polymerase chain reaction and a LightCycler DNA analyzer.
Two patients had 2 mutant alleles, 6 had 3, and 2 had 4. The mean homocysteine, cholesterol, and fibrinogen levels were above the upper limit of normal; the mean folate levels were slightly above the lower limit of normal. Multiple mutations were more frequent in the patient group than in the previously analyzed patients and healthy controls.
The association between inherited and acquired prothrombotic factors in patients with sudden sensorineural hearing loss and thrombotic diseases in other sites suggests that a multifactorial mechanism may underlie microvascular cochlear impairment. Hematologic investigation, including MTHFR, prothrombin, platelet, and V Leiden genotyping, may help to detect patients at potential risk of recurrent hearing loss and multiple microvascular diseases, and could be usefully performed in otherwise idiopathic sudden sensorineural hearing loss.
耳蜗灌注受损似乎是突发性感音神经性听力损失中的一个重要事件。血栓前体基因突变与血管疾病及突发性听力损失有关。我们评估了10例曾发生心血管事件的突发性感音神经性听力损失患者的血栓前体风险，以支持其血管发病机制。
10例患者接受了血液学检测（MTHFR C677T/A1298C、凝血酶原G20210A、血小板糖蛋白IIIa A1/A2和V因子Leiden G1691A基因分型；纤维蛋白原血症；胆固醇血症；高半胱氨酸血症；叶酸血症）。将结果与100例之前仅接受突发性听力损失调查的患者以及200例健康对照者的结果进行比较。从外周血白细胞中分离DNA，并通过聚合酶链反应和LightCycler DNA分析仪研究基因突变。
2例患者有2个突变等位基因，6例有3个，2例有4个。平均高半胱氨酸、胆固醇和纤维蛋白原水平高于正常上限；平均叶酸水平略高于正常下限。患者组中多重突变比之前分析的患者和健康对照者更常见。
突发性感音神经性听力损失患者中遗传性和获得性血栓前体因素与其他部位血栓性疾病之间的关联表明，多因素机制可能是耳蜗微血管损伤背后的原因。包括MTHFR、凝血酶原、血小板和V因子Leiden基因分型在内的血液学调查可能有助于检测有复发性听力损失和多种微血管疾病潜在风险的患者，并且可有效地用于其他方面为特发性的突发性感音神经性听力损失。
