Desbois Delphine, Grangeot-Keros Liliane, Roquebert Bénédicte, Roque-Afonso Anne-Marie, Mackiewicz Vincent, Poveda Jean-Dominique, Dussaix Elisabeth
Centre National de Référence pour les virus à transmission entérique, Laboratoire de Virologie, Hôpital Paul Brousse, Villejuif.
Gastroenterol Clin Biol. 2005 May;29(5):573-6. doi: 10.1016/s0399-8320(05)82132-3.
Diagnosis of acute hepatitis A virus (HAV) infection is classically based on the detection of HAV-IgM. Nevertheless, HAV-IgM can be positive for patients with polyclonal stimulation of their immune system (i.e. immune reactivation). To improve the diagnostic yield, an avidity test for HAV-IgG antibodies was developed and tested.
Avidity tests were performed in 128 sera: 11 selected samples from patients with past infection, 15 acute hepatitis A, 10 vaccinated subjects and 4 patients with immune reactivation as well as 84 HAV-IgM positive unselected sera, provided by routine laboratories.
Patients with past infection had avidities over 70%, whereas avidities in patients with acute hepatitis A were below 50% during the first month following the onset of symptoms. As expected, patients with immune reactivation had avidities over 70% consistent with past infection. The results obtained for the 84 unselected sera allowed reconsidering the diagnosis of acute hepatitis A for nearly a third of patients.
This test could improve the diagnosis of acute hepatitis A infection, particularly in elderly patients.
经典的急性甲型肝炎病毒（HAV）感染诊断基于HAV-IgM的检测。然而，免疫系统多克隆刺激的患者（即免疫激活）体内的HAV-IgM也可能呈阳性。为提高诊断率，研发并测试了一种针对HAV-IgG抗体的亲和力检测方法。
对128份血清进行了亲和力检测：11份选自既往感染患者的样本、15份急性甲型肝炎患者样本、10份接种疫苗者样本、4份免疫激活患者样本以及84份常规实验室提供的未筛选的HAV-IgM阳性血清。
既往感染患者的亲和力超过70%，而急性甲型肝炎患者在症状出现后的第一个月内亲和力低于50%。正如预期的那样，免疫激活患者的亲和力超过70%，与既往感染一致。对84份未筛选血清的检测结果使近三分之一患者的急性甲型肝炎诊断得以重新评估。
该检测方法可改善急性甲型肝炎感染的诊断，尤其是对老年患者。
