Villalta Danilo, Seaman Andrea, Tiongson Marychel, Warren Charles, Bentow Chelsea, Bizzaro Nicola, Alessio Maria Grazia, Porcelli Brunetta, Norman Gary L, Mahler Michael
Immunologia e Allergologia, Ospedale S. Maria degli Angeli, Pordenone, Italy.
Research and Development, Inova Diagnostics, San Diego, CA, USA.
Clin Chem Lab Med. 2020 Apr 10;58(9):1499-1507. doi: 10.1515/cclm-2020-0122. Print 2020 Aug 27.
Anti-mitochondrial autoantibodies (AMA) detected by indirect immunofluorescence (IIF) on rodent tissues are the diagnostic marker of primary biliary cholangitis (PBC). However, up to 15% of patients with PBC are AMA-negative by IIF. In the effort to close the serological gap and improve the diagnostic sensitivity of PBC testing, recently, novel autoantibodies specific for PBC, such as kelch-like 12 (KLHL12, KLp epitope) and hexokinase 1 (HK1) have been described. In this study, we evaluated the autoantibody profile in a large cohort of PBC patients and in patients with other liver disease, including anti-HK1 and anti-KLp autoantibodies.
Sera of 194 PBC patients (126 AMA-IIF-positive and 68 AMA-IIF-negative) and 138 disease controls were tested for a panel of PBC-specific antibodies (MIT3, sp100, gp210, HK1, KLp) using a new automated particle-based multi-analyte technology (PMAT) assay on the Aptiva instrument (Inova).
Selecting a cutoff yielding a specificity of >95% for all the markers, the sensitivity for anti-MIT3, anti-sp100, anti-gp210, anti-HK1 and anti-KLp in the PBC AMA-IIF-negative cohort was 20.6%, 16.2%, 23.5%, 22.0%, 17.6 and 13.2%, respectively. Six out of the 68 (8.8%) AMA-IIF negative sera were positive for anti-HK1 or anti-KLp alone. Using these new markers in addition to anti-MIT3, anti-sp100 and anti-gp210, the overall sensitivity in this cohort of AMA-IIF-negative patients increased from 53% to 61.8%, reducing the serological gap in AMA-negative PBC patients.
PBC antibody profiling, made possible by the new Aptiva-PMAT technology, allows recognition of a higher number of AMA-negative PBC patients than conventional immunoassays and may represent a useful tool to evaluate the prognostic significance of autoantibody association in PBC patients.
通过在啮齿动物组织上进行间接免疫荧光法（IIF）检测到的抗线粒体自身抗体（AMA）是原发性胆汁性胆管炎（PBC）的诊断标志物。然而，高达15%的PBC患者通过IIF检测AMA呈阴性。为了缩小血清学差距并提高PBC检测的诊断敏感性，最近，已描述了一些PBC特异性的新型自身抗体，如kelch样蛋白12（KLHL12，KLp表位）和己糖激酶1（HK1）。在本研究中，我们评估了一大群PBC患者以及其他肝病患者的自身抗体谱，包括抗HK1和抗KLp自身抗体。
使用Aptiva仪器（Inova）上基于微粒的新型自动化多分析物技术（PMAT）检测194例PBC患者（126例AMA-IIF阳性和68例AMA-IIF阴性）以及138例疾病对照的血清中的一组PBC特异性抗体（MIT3、sp100、gp210、HK1、KLp）。
选择一个能使所有标志物特异性>95%的临界值，PBC AMA-IIF阴性队列中抗MIT3、抗sp100、抗gp210、抗HKl和抗KLp的敏感性分别为20.6%、16.2%、23.5%、22.0%、17.6%和13.2%。68例AMA-IIF阴性血清中有6例（8.8%）单独抗HK1或抗KLp呈阳性。除抗MIT3、抗sp100和抗gp210外，使用这些新标志物后，该AMA-IIF阴性患者队列的总体敏感性从53%提高到61.8%，缩小了AMA阴性PBC患者的血清学差距。
新型Aptiva-PMAT技术使PBC抗体谱分析成为可能，与传统免疫测定相比，可识别出更多AMA阴性的PBC患者，并且可能是评估PBC患者自身抗体关联的预后意义的有用工具。
