Department of Neurology, Keio University School of Medicine, Tokyo, Japan.
Pediatr Neurol. 2011 Aug;45(2):114-6. doi: 10.1016/j.pediatrneurol.2011.04.009.
Autoantibodies to signal recognition particle have been associated with juvenile and adult-onset necrotizing myopathy. However, only a few teenage patients with anti-signal recognition particle myopathy have been reported, and to date, to our knowledge, no patient younger than 10 years has been documented. We describe 2 Japanese girls with anti-signal recognition particle myopathy who developed symptoms from the ages of 5 and 9 years, respectively. Both patients had progressive muscle weakness and atrophy without myalgia. Facioscapulohumeral muscular dystrophy was initially suspected because of asymmetric shoulder girdle muscle involvement in one patient, and limb girdle muscular dystrophy due to proximal limb muscle weakness in the other. There were no extramuscular manifestations, including fever or arthritis. Serum creatine kinase levels were elevated to 2,467-4,629 IU/L. Results of muscle biopsy revealed necrotizing myopathy with minimal to mild endomysial fibrosis but without inflammatory infiltrates. Immunosuppressive agents were not effective for muscle weakness, resulting in marked disability. Anti-signal recognition particle myopathy can occur in the first decade of life and should be included in the differential diagnosis for children with progressive limb girdle muscle weakness and high creatine kinase levels.
抗信号识别颗粒自身抗体与青少年和成人发病的坏死性肌病有关。然而，仅有少数青少年抗信号识别颗粒肌病患者被报道，据我们所知，目前尚未有 10 岁以下的患者被记录。我们描述了 2 例日本女孩，她们分别在 5 岁和 9 岁时出现症状。这 2 位患者均有进行性肌无力和肌肉萎缩，但无肌痛。由于 1 位患者存在不对称的肩胛带肌肉受累，最初怀疑为面肩肱型肌营养不良症，而另一位患者则因近端肢体肌无力而被诊断为肢带型肌营养不良症。她们均无肌肉外表现，包括发热或关节炎。血清肌酸激酶水平升高至 2467-4629IU/L。肌肉活检结果显示为伴有轻微至轻度的肌内膜纤维化的坏死性肌病，但无炎症浸润。免疫抑制剂对肌无力无效，导致严重残疾。抗信号识别颗粒肌病可发生在生命的第一个十年，对于进行性肢体带肌无力和高肌酸激酶水平的儿童，应将其纳入鉴别诊断。
