Institute of Laboratory Diagnostics, Hospital of the Brothers of St. John of God, Graz, Austria.
Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University Graz, Graz, Austria.
Clin Chem Lab Med. 2020 Oct 16;59(3):541-546. doi: 10.1515/cclm-2020-1408. Print 2021 Feb 23.
Data on the clinical importance of the detection of anti-dsDNA antibodies in patients with negative indirect immunofluorescence on the HEp-2 cell (IIF) are sparse and are especially not available for all common commercially available assays. This study aimed to assess the clinical significance of anti-dsDNA antibodies determined by the Elia™ dsDNA assay in patients with negative IIF.
We retrospectively examined the medical records of 234 consecutive subjects with detectable anti-dsDNA antibodies determined by the Elia™ dsDNA assay.
A total of 124 subjects with detectable anti-dsDNA autoantibodies were IIF-negative, but yielded positive or borderline results in the Elia™ CTD screen assay for antinuclear antibodies (ANA). Within this group, 6/49 IIF-negative patients (12%) with ANA-associated systemic autoimmune rheumatic disorders (AASARD) and 118/185 subjects (64%) with various other diseases (Non-AASARD) were identified. There was no statistically significant difference with regard to the concentrations of anti-dsDNA antibodies (p=0.53) between the AASARD and the Non-AASARD group. Within the AASARD group, four patients diagnosed with systemic lupus erythematosus (SLE, treated), discoid lupus erythematosus (untreated), indetermined connective tissue disease (untreated) and polymyositis (treated) had positive anti-dsDNA autoantibodies, whereas two patients with treated SLE, thereby one in remission, had borderline concentrations of anti-dsDNA antibodies.
Our findings suggest that the detection of anti-dsDNA antibodies in IIF-negative patients can be of clinical relevance in some cases. Our results further support the combined use of IIF and solid-phase assays in screening algorithms for ANA, in order to avoid overlooking potentially important autoantibody entities.
关于在间接免疫荧光法（IIF）阴性的 HEp-2 细胞上检测抗双链 DNA 抗体的临床重要性的数据很少，特别是对于所有常见的商业上可用的检测方法都没有。本研究旨在评估 Elia™ dsDNA 检测法测定的抗 dsDNA 抗体在 IIF 阴性患者中的临床意义。
我们回顾性地检查了 234 例连续的 Elia™ dsDNA 检测法可检测到抗 dsDNA 抗体的患者的病历。
共有 124 例 IIF 阴性患者的抗 dsDNA 自身抗体可检测到，但在 Elia™ CTD 筛选试验中抗核抗体（ANA）呈阳性或边界值。在这一组中，有 6/49 例 IIF 阴性患者（12%）有与 ANA 相关的系统性自身免疫性风湿性疾病（AASARD）和 118/185 例有各种其他疾病（非 AASARD）的患者被识别出来。AASARD 组和非 AASARD 组之间的抗 dsDNA 抗体浓度无统计学差异（p=0.53）。在 AASARD 组中，四名诊断为系统性红斑狼疮（SLE，治疗中）、盘状红斑狼疮（未治疗）、未确定的结缔组织病（未治疗）和多发性肌炎（治疗中）的患者抗 dsDNA 自身抗体阳性，而两名治疗中的 SLE 患者，其中一名处于缓解期，抗 dsDNA 抗体浓度为边界值。
我们的发现表明，在某些情况下，IIF 阴性患者中抗 dsDNA 抗体的检测可能具有临床意义。我们的结果进一步支持在 ANA 筛选算法中联合使用 IIF 和固相检测，以避免忽略潜在的重要自身抗体实体。
