METHODS: Three cases with myositis from the Myositis Clinical Database of Peking University First Hospital were identified with AMA positivity. Their clinical records were retrospectively reviewed and the data was extracted. All the 3 cases underwent muscle biopsy.
RESULTS: Three middle-aged patients presented with chronic-onset weakness of proximal limbs, marked elevation of creatine kinase, and AMA-positivity. Two of the 3 cases meet the criteria of primary biliary cholangitis. All the 3 cases presented with cardiac involvement and proteinuria. Two cases developed type 2 respiratory failure. MRI of the thigh muscle showed multiple patches of edema bilaterally in both cases, mostly in the adductor magnus. Pathological findings include degeneration of muscle fibers, diffused MHC-I positivity, and complement deposits on cell membranes. Vacuoles without rims of different sizes were discovered under the membrane of the muscle fibers. A few RBFs were discovered in case 1, while a diffused proliferation of endomysium and perimysium was shown in case 2.
CONCLUSIONS: AMA-positive inflammatory myopathy is a disease that could affect multiple systems. Apart from inflammatory changes, the pathological findings of muscle can also present vacuoles.
方法:北京大学第一医院肌炎临床数据库中发现3例肌炎患者AMA阳性。对他们的临床记录进行回顾性审查,并提取数据。3例均行肌肉活检。
结果:三名中年患者表现为慢性起病的近端肢体无力,肌酸激酶明显升高,和AMA阳性。3例中有2例符合原发性胆汁性胆管炎的标准。3例均表现为心脏受累和蛋白尿。2例发生2型呼吸衰竭。两种情况下大腿肌肉的MRI均显示双侧多处水肿,主要是内收肌。病理结果包括肌纤维变性,弥漫性MHC-I阳性,和补体沉积在细胞膜上。在肌纤维膜下发现了没有不同大小边缘的液泡。在情况1中发现了一些RBFs,而在情况2中显示了内膜和周围膜的扩散增殖。
结论:AMA阳性炎性肌病是一种可影响多个系统的疾病。除了炎症改变,肌肉的病理发现也可以呈现空泡。