We present extensive clinical, serological, morphological and muscle imaging data of a 66-year-old man with isolated bilateral ptosis and external ophthalmoplegia secondary to Immune checkpoint inhibitors (Pembrolizumab). He had elevated CK level (>5000 UI/L). No facial, bulbar, proximal, distal or axial muscular weakness was observed. Electromyography (EMG) showed myopathic pattern, with spontaneous activity. Myositis specific antibodies and anti-striational antibodies were negative. Cardiac and respiratory functions were preserved. Skeletal muscle MRI was unremarkable, whereas extraocular muscles revealed bilateral hyperintensities in inferior rectus, medial rectus and superior oblique muscles in both T1 and STIR sequences, with mild muscle atrophy. Muscle biopsy showed endomysial inflammatory infiltrates, MHC-1 expression was observed in clusters of non-necrotic cells. CD56 positive cells were observed in perifascicular regions. Patient discontinued Pembrolizumab and received corticosteroid treatment with progressive clinical improvement and CK normalization. Our findings support this clinical entity, suggesting that isolated ocular myositis represents a subgroup of generalised myositis with predominant ocular symptoms.

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免疫检查点抑制剂 (ICIs) 相关的眼肌炎

我们提供了一名 66 岁男性的广泛临床、血清学、形态学和肌肉成像数据，该男性患有孤立性双侧上睑下垂和继发于免疫检查点抑制剂（派姆单抗）的外部眼肌麻痹。他的 CK 水平升高（>5000 UI/L）。没有观察到面部、延髓、近端、远端或轴向肌肉无力。肌电图 (EMG) 显示肌病模式，具有自发活动。肌炎特异性抗体和抗纹状体抗体均为阴性。心脏和呼吸功能得以保留。骨骼肌 MRI 无异常，而眼外肌在 T1 和 STIR 序列中显示双侧下直肌、内直肌和上斜肌高信号，伴有轻度肌肉萎缩。肌肉活检显示肌内膜炎症浸润，在非坏死细胞簇中观察到 MHC-1 表达。在束周区域观察到CD56阳性细胞。患者停用派姆单抗并接受皮质类固醇治疗，临床逐渐改善且 CK 正常化。我们的研究结果支持这一临床实体，表明孤立性眼肌炎代表了以眼部症状为主的全身性肌炎的一个亚组。