From the University of Western Ontario, Schulich School of Medicine and Dentistry, Department of Medicine; Division of Rheumatology, Department of Medicine, St. Joseph's Health Care, London, Ontario, Canada.
T.C. Raissi, BSc, University of Western Ontario, Schulich School of Medicine and Dentistry; C. Hewson, MD, FRCPC, BSc, University of Western Ontario, Schulich School of Medicine and Dentistry, Department of Medicine; J.E. Pope, MD, MPH, FRCPC, University of Western Ontario, Schulich School of Medicine and Dentistry, Department of Medicine, and Professor of Medicine, Division Head, Division of Rheumatology, St. Joseph's Health Care.
J Rheumatol. 2018 Jun;45(6):827-834. doi: 10.3899/jrheum.161365. Epub 2018 Apr 15.
Patients with systemic lupus erythematosus (SLE) frequently undergo repeat testing for antibodies against extractable nuclear antigens (anti-ENA), but it is not known whether this is necessary or cost-effective. This study characterized the frequencies of changes in anti-ENA, anti-dsDNA, and complement C3 and C4 upon repeat testing.
Chart review was done at one site of 130 patients with SLE enrolled in the 1000 Canadian Faces of Lupus prospective registry with annual antibody and complement testing. We determined the frequency of seroconversion (changes) on the next test and over the entire followup given 1 or multiple consistent results, and the cost to detect these changes.
Overall, 89.4% of patients had no changes in anti-ENA screening results from the first available test, 3.3% changed from negative to positive, and 7.3% from positive to negative. Following a single anti-ENA test, 3.9% of negative tests changed to positive and 4.2% of positive changed to negative on the next test. After multiple consistent tests, the frequencies of changes progressively declined. No changes from the first test were observed in anti-dsDNA, C3, and C4 in 60.8%, 83.3%, and 75.4% of patients, respectively. After 2 consistent anti-ENA tests, the cost to detect 1 change was above US$2000.
Anti-ENA results change infrequently, especially following 1 or more negative tests. The high cost and lack of evidence that changes affect management suggest that repeating anti-ENA tests routinely is unnecessary. Anti-dsDNA and complements change more frequently after an abnormal result, but less after a normal value.
系统性红斑狼疮（SLE）患者经常需要重复进行针对可提取核抗原（ENA）的抗体检测，但目前尚不清楚这是否有必要或具有成本效益。本研究旨在描述重复检测时 ENA、抗双链 DNA（dsDNA）抗体和补体 C3、C4 变化的频率。
对参与加拿大 1000 名狼疮患者前瞻性登记研究的 130 例 SLE 患者的图表进行回顾性分析，该研究每年进行抗体和补体检测。我们确定了在获得下一个测试结果时以及在整个随访期间（基于 1 次或多次一致的结果）出现血清学转换（变化）的频率，以及检测这些变化的成本。
总体而言，89.4%的患者首次可获得的 ENA 筛查结果无变化，3.3%由阴性转为阳性，7.3%由阳性转为阴性。单次 ENA 检测后，3.9%的阴性检测结果在下一次检测中转为阳性，4.2%的阳性检测结果转为阴性。经过多次连续检测，变化的频率逐渐下降。在首次检测中，60.8%、83.3%和 75.4%的患者的抗 dsDNA、C3 和 C4 分别无变化。经过 2 次连续的 ENA 检测后，检测 1 次变化的成本超过 2000 美元。
ENA 结果变化不频繁，尤其是在进行 1 次或更多次阴性检测之后。成本高且缺乏变化会影响管理的证据表明，常规重复进行 ENA 检测是没有必要的。抗 dsDNA 和补体在异常结果后变化更频繁，但在正常值后变化较少。
