Neuropathology Department, John Radcliffe Hospital, Oxford University Hospitals Trust, Oxford, UK.
Translational Neurology and Neurophysiology Laboratory, Advance Clinical Research Centre, School of Medicine, Universidad de Chile, Santiago, Chile.
Muscle Nerve. 2023 Jan;67(1):73-77. doi: 10.1002/mus.27739. Epub 2022 Nov 4.
INTRODUCTION/AIMS: p62 immunochemistry (IHC) has been shown to aid diagnosis with distinct patterns of muscle fiber staining observed in some inflammatory, hereditary, and degenerative myopathies, such as immune-mediated necrotizing myopathy (IMNM). The pattern of p62 staining may help narrow the pathological differential diagnosis of rhabdomyolysis. However, there is a lack of information on the pattern of p62 IHC in non-immune-mediated rhabdomyolysis. In this study we aim to describe histopathological findings in non-immune-mediated rhabdomyolysis, with particular emphasis on the pattern of p62 IHC.
We retrospectively reviewed the histopathological features of patients with a confirmed diagnoses of non-immune-mediated rhabdomyolysis referred to our center.
Five patients were identified. Rhabdomyolysis was determined to be due to statin-associated toxicity in three patients, alcohol overuse in one patient, and intensive exercise in one patient. All patients showed increased numbers of necrotic and regenerating muscle fibers. Diffuse and finely granular sarcoplasmic positive p62 staining was present in scattered non-necrotic muscle fibers in all patients.
Disturbance of autophagy appears to be a common mechanism in non-immune-mediated rhabdomyolysis. Our results show p62 IHC is sensitive but lacks specificity. Therefore, the pattern of p62 staining does not distinguish non-immune-mediated rhabdomyolysis from histopathologically similar IMNM.
介绍/目的：已经证明 p62 免疫化学（IHC）有助于诊断，在一些炎症性、遗传性和退行性肌病中观察到肌纤维染色的独特模式，例如免疫介导的坏死性肌病（IMNM）。p62 染色模式可能有助于缩小横纹肌溶解症的病理鉴别诊断范围。然而，关于非免疫介导的横纹肌溶解症中 p62 IHC 的模式信息有限。在这项研究中，我们旨在描述非免疫介导的横纹肌溶解症的组织病理学发现，特别强调 p62 IHC 的模式。
我们回顾性地审查了转诊至我们中心的确诊为非免疫介导的横纹肌溶解症患者的组织病理学特征。
确定了五名患者。三名患者的横纹肌溶解症归因于他汀类药物相关毒性，一名患者归因于酒精过度使用，一名患者归因于剧烈运动。所有患者均显示出数量增加的坏死和再生肌纤维。所有患者均有散在的非坏死肌纤维中出现弥漫性和细颗粒状细胞质 p62 染色阳性。
自噬紊乱似乎是非免疫介导的横纹肌溶解症的常见机制。我们的结果表明 p62 IHC 具有敏感性但缺乏特异性。因此，p62 染色模式无法区分非免疫介导的横纹肌溶解症与组织病理学上相似的 IMNM。
