Horneff G, Paetzke I, Neuen-Jacob E
Department of Paediatrics, University Hospital, Martin-Luther University Halle-Wittenberg, Germany.
Clin Rheumatol. 2001;20(1):57-60. doi: 10.1007/s100670170105.
A 13-year-old girl was referred to our clinic because of a positive rheumatoid factor test, muscle pain and weakness. Laboratory evaluation revealed an increased ESR, hypergammaglobulinaemia, antinuclear antibodies, circulating immune complexes, complement consumption and elevated serum creatine kinase (CK) activity. A needle biopsy of the dolent muscle showed normal routine histology. Immunohistochemistry disclosed single lymphocytes and a weak myocytic HLA class I expression. The diagnosis of myositis was considered and corticosteroids were initiated, leading to an increase of complement levels and a decrease of CK-activity and ESR. She subjectively felt stronger but still reported exercise intolerance and metabolic myopathy was considered. Myophosphorylase activity was completely lacking, establishing the diagnosis of McArdle's disease. CK level was found to be elevated in an obese 4-year-old brother too, who refused extensive walking but reported no muscle pain. Myophosphorylase deficiency was demonstrated by histochemistry and by biochemical analysis of his muscle. The female case illustrates that in children with the clinical picture of inflammatory myopathy and serological but not clinical response to therapy underlying metabolic muscle disorders should be excluded. Since the pathogenesis of polymyositis remains unclear, we speculate that inflammatory changes observed in the muscles may have been initiated by muscular damage resulting from the underlying metabolic disease. The serological changes remained unexplained and may contribute to a so far undeterminable connective tissue disease.
一名13岁女孩因类风湿因子检测呈阳性、肌肉疼痛和无力被转诊至我们的诊所。实验室检查显示血沉加快、高丙种球蛋白血症、抗核抗体、循环免疫复合物、补体消耗以及血清肌酸激酶（CK）活性升高。对疼痛肌肉进行针吸活检，常规组织学检查显示正常。免疫组化显示有单个淋巴细胞以及肌细胞HLA I类表达较弱。考虑诊断为肌炎，并开始使用皮质类固醇治疗，这导致补体水平升高、CK活性和血沉降低。她主观感觉体力增强，但仍报告有运动不耐受，考虑存在代谢性肌病。肌磷酸化酶活性完全缺乏，从而确诊为麦克尔憩室病。在一名肥胖的4岁弟弟身上也发现CK水平升高，他拒绝长时间行走，但未报告肌肉疼痛。通过组织化学和对其肌肉的生化分析证实存在肌磷酸化酶缺乏。该女性病例表明，对于有炎症性肌病临床表现且对治疗有血清学而非临床反应的儿童，应排除潜在的代谢性肌肉疾病。由于多发性肌炎的发病机制仍不清楚，我们推测在肌肉中观察到的炎症变化可能是由潜在代谢疾病导致的肌肉损伤引发的。血清学变化仍无法解释，可能与一种迄今尚未确定的结缔组织疾病有关。
