简体中文

AC-0-阴性

同义词 无 None
描述

这些图像是HEp-2 IFA阴性(显微镜下观察)的示例。由于ANA阴性图像会有不同的呈现形式，所以AC-0不能当做绝对的ANA 阴性 [1]，只是作为一个对照。为什么会有这么多种可能的变化是由于目前缺乏明确的细胞内结构染色标准，且比较主观并只能做到半定量。

在使用电脑屏幕在线读取AC-0图像时，应注意不同的电脑默认的屏幕亮度设置也是不同的，可能需要做一些调整从而到正确的解读。对于有两个屏幕的电脑来说，其屏幕的亮度也不一定是同步的。这些AC-0的图片用于展示一些细胞的清晰度，包括分裂中期的细胞，如果不能看到足够的细节，则可能是屏幕亮度设置太暗;另一方面，如果这些图片的绿色荧光较强，请考虑是否屏幕亮度设置得太亮。总之，在电脑屏幕上读取这些图像时应该根据情况相应地调整屏幕的亮度设置。
值得注意的是，在计算机辅助诊断显微镜系统已在许多临床实验室中普遍应用的背景下，AC-0 的设置仍需要相应地进行考量和评估，因为它通常并不等同于传统显微镜下的对应设置。
关于HEp-2 IFA阳性与阴性临界值如何确定的问题，目前的共识是，临界值应通过实验并结合当地情况，使用表观健康的、年龄匹配的正常对照人群来确立。同时，临界值的确定高度依赖于不同实验室所使用的HEp-2基质，包括因不同制造商和不同批次来源的HEp-2载片本身的差异、荧光染料偶联的二抗试剂、显微镜和相机的设置、血清稀释度以及其他变量。
关于HEp-2 IFA检测所用的绝对筛查稀释度，目前尚无统一共识[2]。建议实验室在检验前概率较低（即普通人群筛查）的样本时采用1：160稀释度，而在检验前概率较高（即临床高度怀疑自身免疫性疾病的患者）的样本时采用1：80稀释度。为保持透明度和可比性，也强烈建议最终的HEp-2 IFA报告中注明所使用的具体筛查稀释度[3]。
另请注意，AC-0的命名表示未观察到具有临床意义的荧光染色模式。AC-0 并不一定意味着不存在自身抗体和/或自身免疫性疾病，因为有时特定样本中的自身抗体并不识别HEp-2细胞上所表达的目标自身抗原的表位。这一点对于抗 TRIM21/Ro52 [4]、TROVE2/Ro60 [4]、tRNA 合成酶（如 Jo-1、PL-7、PL-12 等）以及核糖体 P 蛋白的抗体尤其相关。另请注意，AC-0 不应与 AC-XX（未分类的 AC 模式）相混淆。
These images are provided as examples of what are considered HEp-2 IFA-negative as viewed with an immunofluorescence microscope. Since a negative HEp-2 IFA can be represented by different non-specific and ill-defined fluorescence images, it should be clear that these AC-0 examples [1] should not be regarded as the entire array of possibilities, but rather representative examples only. The guiding features that link these images are the absence of clear-cut staining of any subcellular structure(s) and the dim and ill-defined nature of the fluorescent signal. This definition is both subjective and semi-quantitative. In viewing these AC-0 images, it is important to note that the viewing screen default brightness and contrast settings may vary from computer (device) to computer (device) and adjustments may be necessary for appropriate interpretation. For example, for computers with two screens, the brightness and contrast between both screens is sometimes not synchronized, which can be attributed to image variations on a single computer. These AC-0 images were selected to show a marginal definition of cells, including cells in metaphase. If one cannot see the cells, the screen brightness is likely set too dark. On the other hand, if these images show too much green staining, please consider that the screen brightness may be set too bright. In summary, viewers of these images should make appropriate adjustments to their viewing screen brightness settings. Note that with the Computer-Aided Diagnosis microscope systems becoming common in many clinical laboratories, the setting for AC-0 needs to be considered accordingly as it is often not reflecting the equivalent in the traditional microscope. As to how HEp-2 IFA-positive vs -negative cut-off is determined, there is consensus that cut-offs should be determined experimentally and locally using apparently healthy and age-relevant population controls. The cut-off is highly dependent on the HEp-2 substrate used by individual laboratories, including factors specific to different HEp-2 slide manufacturers, lot-to-lot variations, fluorochrome-conjugated secondary antibody reagents, microscope optical system and light power, camera and viewing monitor settings, serum screening dilutions, and other variables. The absolute screening dilution used for HEp-2 IFA is not universally agreed upon [2]. It is recommended that a 1:160 dilution should be used by laboratories testing samples with low pre-test probability (i.e., general population screening) and 1:80 dilution for samples with high pre-test probability (i.e., patients with a strong clinical suspicion of autoimmune disease). To maintain transparency and comparability, it is also strongly recommended that the final HEp-2 IFA report includes the specific screening dilution used [3]. Also note that the AC-0 designation infers no clinically relevant patterns are observed. AC-0 does not necessarily mean the absence of autoantibodies and/or autoimmune disease because sometimes the autoantibodies in a particular sample do not recognize epitopes of the target autoantigen as expressed in the HEp-2 cell. This is particularly relevant for antibodies against TRIM21/Ro52 [4], TROVE2/Ro60 [4], tRNA synthetases (i.e., Jo-1, PL-7, PL-12, etc), and ribosomal P. Also note that AC-0 should not be confused with AC-XX (unclassified AC- pattern).
抗原相关性 不适用。已知 HEp-2 IFA 对检测与以下抗原反应的自身抗体敏感性较低，包括但不限于：TRIM21/Ro52、TROVE2/Ro60、tRNA 合成酶（如 Jo-1、PL-7、PL-12 等）以及核糖体 P 蛋白。 Not applicable. HEp-2 IFA is known to be less sensitive for the detection of autoantibodies reactive with, among others, TRIM21/Ro52, TROVE2/Ro60, tRNA synthetases (i.e., Jo-1, PL-7, PL-12, etc.), and ribosomal P.

  • 临床相关性

    一级信息

    关于临床相关性和缩写列表

    Clinical Relevance

    First level information

    About Clinical Relevance & List of Abbreviations
  • HEp-2 IFA（间接免疫荧光法）阴性结果意味着患系统性自身免疫性风湿病的概率非常低，但仍不能排除其他自身免疫性疾病。对于系统性红斑狼疮、混合性结缔组织病、系统性硬化症、原发性干燥综合征和特发性炎性肌病等检验前概率较低的病例，该检测具备较高的阴性预测价值。
    A negative HEp-2 IFA result is associated with a very low probability of having a systemic autoimmune rheumatic disease, but it does not exclude other autoimmune diseases. It has considerable negative predictive value in cases with low pre-test probability of systemic lupus erythematosus, mixed connective tissue disease, systemic sclerosis, primary Sjögren’s disease, and idiopathic inflammatory myopathies.
  • 二级信息
    Second level information
  • 无
    None
  • 参考文献
  • 1.Herold M, Klotz W, Andrade LEC, Conrad K, de Melo Cruvinel W, Damoiseaux J, Fritzler MJ, von Muhlen CA, et al. International Consensus on Antinuclear Antibody Patterns: defining negative results and reporting unidentified patterns. Clin Chem Lab Med. 2018;56:1799-802
    2.Naides SJ, Genzen JR, Abel G, Bashleben C, Ansari MQ. Antinuclear Antibodies Testing Method Variability: A Survey of Participants in the College of American Pathologists Proficiency Testing Program. J Rheumatol. 2020;47:1768-73
    3.von Muhlen CA, Garcia-De La Torre I, Infantino M, Damoiseaux J, Andrade LEC, Carballo OG, Conrad K, Francescantonio PLC, et al. How to report the antinuclear antibodies (anti-cell antibodies) test on HEp-2 cells: guidelines from the ICAP initiative. Immunol Res. 2021;69:594-608
    4.Choi M, Andrade LEC, Chan EKL, Fritzler MJ, Ben-Chetrit E, et al. Autoantibody nomenclature harmonization: Ro, SSA, TRIM21 and TROVE2. in preparation. 2025


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