Department of Medicine, Shaare Zedek Medical Center, 12 Shmuel Bait St, PO Box 3235, 91031022, Jerusalem, Israel.
Nephrology Unit, Shaare Zedek Medical Center, 12 Shmuel Bait St., PO Box 3235, 9103102, Jerusalem, Israel.
Intern Emerg Med. 2021 Mar;16(2):429-436. doi: 10.1007/s11739-020-02518-6. Epub 2020 Oct 6.
ANCA testing plays an established critical role in the diagnosis of ANCA Associated vasculitis (AAV). The spectrum of diseases associated with positive ANCA has recently broadened, thus calling into question the diagnostic implications of ANCA positivity in a hospital setting. We retrospectively studied all adult patients who had a positive ANCA test (by Indirect Immunofluorescence (IIF), ELISA or both) performed over the span of 19 years. Subjects were then divided into discordant (positive on one assay) and concordant ANCA (positive on both assays) groups based on their ANCA positivity status. The two groups were then compared with regards to their demographic, clinical and laboratory characteristics, the indication for ANCA testing in both groups and their final diagnoses. Of the 9189 ANCA tests ordered during the 19-year span of the study, 389 (4.2%) were positive. Two hundred and forty subjects met the exclusion criteria (patients aged less than 18 years or the lack of clinical and laboratory data in the medical file) thus resulting in a final cohort of 149 subjects. Of them, 122 subjects had discrepant ANCA results and 27 had matching ANCA results. Most cases in the discrepancy group were IIF positive and ELISA negative (86.8%). The diagnosis of AAV was highly unlikely in cases with discrepant IIF and ELISA serologies compared to cases with matching IIF and ELISA serologies (4.1% versus 44.4%, p value < 0.001). The diagnosis of AAV in unlikely in subjects with discrepancies between IIF and ELISA, particularly with only positive IIF.
抗中性粒细胞胞浆抗体（ANCA）检测在诊断抗中性粒细胞胞浆抗体相关性血管炎（AAV）中起着重要作用。与阳性 ANCA 相关的疾病谱最近已经扩大，这使得 ANCA 阳性在医院环境中的诊断意义受到质疑。我们回顾性研究了在 19 年期间进行过阳性 ANCA 检测（间接免疫荧光法（IIF）、酶联免疫吸附试验（ELISA）或两者均有）的所有成年患者。然后，根据他们的 ANCA 阳性状态，将患者分为不一致（一种检测方法阳性）和一致的 ANCA（两种检测方法均阳性）组。然后比较两组患者的人口统计学、临床和实验室特征、两组进行 ANCA 检测的指征以及最终诊断。在研究的 19 年期间，共进行了 9189 次 ANCA 检测，其中 389 次（4.2%）为阳性。240 名患者因年龄小于 18 岁或病历中缺乏临床和实验室数据而不符合排除标准，因此最终纳入了 149 名患者。其中，122 名患者的 ANCA 结果不一致，27 名患者的 ANCA 结果一致。在不一致组中，大多数病例的 IIF 阳性和 ELISA 阴性（86.8%）。与 IIF 和 ELISA 血清学匹配的病例相比，不一致的 IIF 和 ELISA 血清学病例的 AAV 诊断可能性较低（4.1%对 44.4%，p 值<0.001）。与 IIF 和 ELISA 不一致的患者，特别是仅 IIF 阳性的患者，不太可能诊断为 AAV。
