PDF(Pubmed)
Abstract：
For antinuclear antibody (ANA) screening, the gold standard method is an indirect immunofluorescence assay (IIFA) using HEp-2 cells, and a serial dilution test is needed to determine the endpoint titer. We aimed to evaluate the accuracy of the estimated endpoint titer (eEPT) by the NOVA View system, by comparing it with the EPT by the serial dilution method (dEPT). The endpoint titers of a total of 1518 ANA positive cases with five major patterns including speckled, homogeneous, centromere, nucleolar, and nuclear dots patterns were determined using both the estimation function and the serial dilution method by the NOVA View system. A significant correlation between the light intensity unit (LIU) values and dEPTs was identified in all five patterns with high ρ values, ranging from 0.666 to 0.832. However, the overall exact match rate between dEPT and eEPT was 22.1% (336/1518), with the ±one-titer match rate being highest in the centromere pattern (62.8%, 81/129), and lowest in the homogeneous pattern (37.6%, 200/532). This suggests that while LIU values correlate well with dEPT, there are discrepancies in numerical agreement. Most cases that did not show an exact match, showed one-to-three-titer overestimations by eEPT. Therefore, adjusting eEPT downward significantly improved the concordance rates with dEPTs. Further investigation for an appropriate cutoff of LIU values for determining eEPT should be performed for clinical application and contribution to the standardization of the ANA titer.
摘要：
抗核抗体（ANA）筛查，金标准方法是使用HEp-2细胞的间接免疫荧光测定（IIFA），并且需要进行连续稀释测试来确定终点滴度。我们旨在通过NOVAView系统评估估计终点滴度（eEPT）的准确性，通过与连续稀释法(dEPT)的EPT进行比较。共有1518例ANA阳性病例的终点滴度有五种主要模式，包括斑点，同质，着丝粒,核仁,通过NOVAView系统使用估计函数和连续稀释方法确定核点图案。在具有高ρ值的所有五个模式中，确定了光强度单位（LIU）值与dEPT之间的显着相关性，范围从0.666到0.832。然而,dEPT和eEPT的总体精确匹配率为22.1%(336/1518)，着丝粒模式的±一滴度匹配率最高(62.8%，81/129),在同质模式中最低(37.6%，200/532）。这表明，虽然LIU值与dEPT有很好的相关性，数字协议存在差异。大多数没有显示完全匹配的案例，通过eEPT显示一到三滴度的高估。因此,向下调整eEPT显著提高了与dEPT的一致率。对于临床应用和对ANA滴度标准化的贡献,应进行进一步研究以确定用于确定eEPT的LIU值的适当截止值。
