Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Pathology, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
Lupus. 2021 Apr;30(4):587-596. doi: 10.1177/0961203320984539. Epub 2021 Jan 7.
Renal involvement is seen in about 40-82% of systemic lupus erythematosus (SLE) Asian patients. The exact diagnosis and classification of lupus nephritis are important for treatment and prognosis. This study aimed to investigate the value of electron microscopy (EM) in the diagnosis and classification of lupus nephritis compared with light microscopy.
In this cross-sectional referral-center 16-year study of lupus nephritis, the final diagnosis was based on the EM study. Primary light microscopy findings were compared with EM diagnosis. Moreover, Immunofluorescence patterns distribution was assessed.
From 496 patients diagnosed with lupus nephritis based on EM, 225(45.4%) of patients were categorized in class IV, followed by 98(19.7%), 93(18.8%), 46(9.3%), and 14(2.8%) who were categorized into classes of II, III, V, and VI respectively. Only 1(0.2%) patient belonged to class I, and 19(3.8%) cases were diagnosed with mixed two classes. Using EM was essential for diagnosing 25.6% of cases taking the correct classification by light microscopy into account; however, disregarding correct classification, this could change to a 7.4% contribution rate of EM. The most common cause of misdiagnosis, disregarding incorrect classification, was inadequate or wrong tissue. Positive associations were detected between tubular atrophy and interstitial fibrosis of both electron and light microscopy with different classes (P < 0.001).
While light microscopy is highly accurate for diagnosing lupus nephritis regardless of correct classification, EM contributes substantially to the correct classification of lupus nephritis types.
大约 40-82%的系统性红斑狼疮（SLE）亚洲患者存在肾脏受累。狼疮肾炎的准确诊断和分类对于治疗和预后非常重要。本研究旨在探讨与光镜相比，电子显微镜（EM）在狼疮肾炎诊断和分类中的价值。
在这项为期 16 年的狼疮肾炎的横断面转诊中心研究中，最终诊断基于 EM 研究。将主要光镜发现与 EM 诊断进行比较。此外，还评估了免疫荧光模式的分布。
从基于 EM 诊断为狼疮肾炎的 496 例患者中，225 例（45.4%）患者被归类为 IV 类，其次是 98 例（19.7%）、93 例（18.8%）、46 例（9.3%）和 14 例（2.8%）分别归类为 II、III、V 和 VI 类。只有 1 例（0.2%）患者属于 I 类，19 例（3.8%）患者被诊断为混合两类。考虑到光镜的正确分类，EM 对 25.6%的病例的正确诊断是必不可少的；然而，如果不考虑正确的分类，这可能会使 EM 的贡献比例从 7.4%变为 3.8%。在不考虑错误分类的情况下，最常见的误诊原因是组织不足或不正确。电子显微镜和光镜的肾小管萎缩和间质纤维化与不同的分类之间存在阳性关联（P<0.001）。
尽管光镜在正确分类的情况下对狼疮肾炎的诊断具有高度准确性，但 EM 对狼疮肾炎类型的正确分类有很大贡献。
