de Lima Montalvão Silmara Aparecida, Tucunduva Alini Camargo, de Almeida Sambo Andrea Luísa, De Paula Erich Vinicius, de Souza Medina Samuel, Ozelo Margareth Castro
IHTC Hemophilia Unit "Cláudio L. P. Corrêa", Instituto Nacional de Ciência e Tecnologia do Sangue, Hemocentro Unicamp, University of Campinas, São Paulo, Brazil.
IHTC Hemophilia Unit "Cláudio L. P. Corrêa", Instituto Nacional de Ciência e Tecnologia do Sangue, Hemocentro Unicamp, University of Campinas, São Paulo, Brazil.
Thromb Res. 2015 Dec;136(6):1280-4. doi: 10.1016/j.thromres.2015.08.014. Epub 2015 Aug 28.
Nijmegen-Bethesda assay is the gold standard to assess inhibitory antibodies against factor (F) VIII. This method has some limitations, including high coefficient of variation and possible interference of residual endogenous or exogenous factor VIII. Heat-treatment of samples at 56 °C for 30 min could be a strategy to improve the sensitivity of this test. The aim of this study was to compare inhibitor quantification in hemophilia patients with and without inhibitor performed in previously heated and non-heated samples. A total of 109 analyses from 46 patients with severe hemophilia A were performed. Patients were divided into three groups: 20 patients with no history of inhibitor, recently and not recently exposed to FVIII (group I), 21 patients with history of inhibitor not exposed to FVIII (group II), and 5 patients (68 samples) undergoing an immune tolerance induction (ITI) protocol (group III). For patients with no history of inhibitor, heat-treatment did not modify the results (p=0.24). However, differences in inhibitor levels between heated and non-heated samples were observed in patients with history of inhibitor (group II, p<0.05) and in patients in ITI (group III, p<0.001). In 11 samples, inhibitor quantification shifted from negative to positive. Additionally, a longitudinal evaluation of each ITI patient showed similar trend line for the results of heated and non-heated samples. In this study, we demonstrated that heating samples increase sensitivity of Nijmegen-Bethesda assay, with no shift from negative to positive results in patients with no history of inhibitor. Furthermore, this procedure has an important role to patients undergoing an ITI protocol.
奈梅亨-贝塞斯达检测法是评估抗凝血因子（F）VIII抑制性抗体的金标准。该方法存在一些局限性，包括变异系数高以及内源性或外源性凝血因子VIII残留可能产生的干扰。将样本在56℃热处理30分钟可能是提高该检测灵敏度的一种策略。本研究的目的是比较在经过热处理和未经过热处理的样本中，对有和没有抑制物的血友病患者进行抑制物定量分析的结果。对46例重度甲型血友病患者共进行了109次分析。患者被分为三组：20例无抑制物病史、近期和非近期接触过FVIII的患者（第一组），21例有抑制物病史但未接触过FVIII的患者（第二组），以及5例（68个样本）正在接受免疫耐受诱导（ITI）方案治疗的患者（第三组）。对于无抑制物病史的患者，热处理并未改变检测结果（p=0.24）。然而，在有抑制物病史的患者（第二组，p<0.05）和接受ITI治疗的患者（第三组，p<0.001）中，观察到热处理样本和未热处理样本之间的抑制物水平存在差异。在11个样本中，抑制物定量结果从阴性变为阳性。此外，对每位接受ITI治疗患者的纵向评估显示，热处理样本和未热处理样本的结果具有相似的趋势线。在本研究中，我们证明加热样本可提高奈梅亨-贝塞斯达检测法的灵敏度，且无抑制物病史的患者检测结果不会从阴性变为阳性。此外，该程序对正在接受ITI方案治疗的患者具有重要作用。
