肢带型肌营养不良症2B型与免疫介导的坏死性肌病临床及影像学差异分析

Clinical and imaging differences between limb-girdle muscular dystrophy type 2B and immune-mediated necrotizing myopathy

目的探讨肢带型肌营养不良症2B型(LGMD2B)与免疫介导的坏死性肌病(IMNM)的临床和影像学差异。方法纳入2014年1月至2018年12月收治的LGMD2B型(45例)和IMNM(45例)患者,记录性别、发病年龄、确诊年龄和延误就诊时间;酶耦联法测定血清肌酸激酶水平;英国医学研究理事会6级测定法评价颈屈肌、上肢近端和远端肌力、下肢近端和远端肌力并计算肌力百分比;双大腿MRI评价骨骼肌脂肪浸润和水肿程度。结果LGMD2B型患者发病年龄(Z=-3.605,P=0.000)和确诊年龄(Z=-2.757,P=0.006)早于、就诊延误时间长于(Z=-4.749,P=0.000)、血清肌酸激酶水平高于(Z=-2.247,P=0.025)IMNM患者。IMNM患者颈屈肌肌力(Z=-6.320,P=0.000)和肌力百分比(t=-6.320,P=0.000),以及上肢近端肌力(Z=-3.528,P=0.000)和肌力百分比(t=-3.762,P=0.000)低于LGMD2B型患者,而LGMD2B型患者下肢远端肌力(Z=-3.256,P=0.001)和肌力百分比(t=-2.883,P=0.004)低于IMNM患者。LGMD2B型患者双大腿前群肌(Z=-3.119,P=0.002)和后群肌(Z=-2.534,P=0.011)脂肪浸润程度高于IMNM患者,而IMNM患者双大腿后群肌水肿程度高于LGMD2B型患者(Z=-3.887,P=0.000)。结论与IMNM患者相比,LGMD2B型患者发病年龄更早、延误就诊时间更长、下肢远端肌力更差、血清肌酸激酶水平更高、大腿肌肉脂肪浸润程度更严重;而IMNM患者则呈现更为严重的颈屈肌和上肢近端肌无力,以及明显的大腿后群肌水肿。

Objective To investigate the clinical and imaging differences between limb-girdle muscular dystrophy type 2B(LGMD2B)and immune-mediated necrotizing myopathy(IMNM).Methods Forty-five patients with LGMD2B and 45 patients with IMNM from January 2014 to December 2018 were included.Sex,age of onset,age of diagnosis and time of delay in admission were recorded,and serum creatine kinase(CK)level was measured.Cervical flexion,proximal and distal upper limbs,proximal and distal lower limbs were evaluated by Medical Research Council(MRC)Level 6 and muscle strength percentages were calculated.Skeletal muscle fatty infiltration and edema degree on both thighs were evaluated by MRI.Results The onset age(Z=-3.605,P=0.000)and diagnosis age(Z=-2.757,P=0.006)of LGMD2B patients were earlier than those of IMNM patients,while the delay time of admission was longer than that of IMNM patients(Z=-4.749,P=0.000),the serum CK was higher than that of IMNM patients(Z=-2.247,P=0.025).The muscle strength of neck flexion(Z=-6.320,P=0.000)and percentage of muscle strength(t=-6.320,P=0.000),the muscle strengh of proximal upper extremities(Z=-3.528,P=0.000)and percentage of muscle strength(t=-3.762,P=0.000)in IMNM patients were lower than those in LGMD2B patients,while the muscle strengh of distal lower extremity(Z=-3.256,P=0.001)and percentage of muscle strength(t=-2.883,P=0.004)in LGMD2B patients were lower than those in IMNM patients.LGMD2B patients had higher muscle fatty infiltration degree in anterior group(Z=-3.119,P=0.002)and posterior group(Z=-2.534,P=0.011)of thigh muscle than IMNM patients,but IMNM patients had highter thigh muscle edema degree in posterior group than LGMD2B patients(Z=-3.887,P=0.000).Conclusions Compared with IMNM patients,LGMD2B patients had earlier onset age,longer delay in diagnosis time,worse muscle strength of distal lower extremities,higher serum CK and more obviously thigh muscle fatty infiltration.In IMNM patients,muscle weakness of neck flexion and proximal upper extremities,thigh muscle edema of posterior group were more obvious.These characteristics contribute to the clinical differentiation of the two diseases.