Myopathy with anti-signal recognition particle antibodies: clinical and histopathological features in Chinese patients.
Myopathy with anti-signal recognition particle antibodies (SRP) is generally thought to be immune-mediated necrotic myopathy in previous studies. We report the clinical and histopathological features of myopathy with anti-SRP antibodies in Chinese patients. Muscle biopsy and immunoblots for myositis antibodies were carried out in 123 patients with idiopathic inflammatory myopathy. Among them, 16 (13.0%) patients had anti-SRP antibodies. Age of onset ranged from 24 to 77 years, and the disease began insidiously. Fourteen of 16 patients presented with chronic progression of proximal limb weakness, with 6 having myalgia. Serum creatine kinase levels ranged from 400 to 9082 IU/L. Muscle biopsies showed necrotic and/or regenerative muscle fibers in all 16, infiltrates of lymphocytes in 11 and morphological features of muscular dystrophy in 7. Eleven patients showed focal or diffuse major histocompatibility complex class 1 expression in sarcolemma or cytoplasm of muscle fibers, with 9 showing deposition of membrane attack complex in necrotic muscle fibers and 2 around capillaries. These findings indicate that anti-SRP antibodies are most likely to be related to IMNM. Myopathy with anti-SRP antibodies is not infrequent in Chinese patients with idiopathic inflammatory myopathy.
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Lu
L
Wang
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Linlin
L
Liu
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Hongjun
H
Hao
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Feng
F
Gao
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Xiao
X
Liu
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Zhaoxia
Z
Wang
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Wei
W
Zhang
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
He
H
Lv
Department of Neurology, Peking University First Hospital, Beijing 100034, China. Electronic address: yuanyun2002@126.com.
Yun
Y
Yuan
D000328:Adult; D000368:Aged; D044466:Asian People; D001323:Autoantibodies / Q000097:blood*; D002681:China; D003402:Creatine Kinase / Q000097:blood; D018450:Disease Progression; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000473:pathology / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D063806:Myalgia / Q000503:physiopathology; D009220:Myositis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology*; D018271:Signal Recognition Particle / Q000276:immunology*; D013848:Thigh / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult
D001323:Autoantibodies; D018271:Signal Recognition Particle; D003402:Creatine Kinase
Immunoblot; Myositis; Pathology; Signal recognition particle