Case of the Month
Myositis with antimitochondrial antibodies diagnosed by rectus abdominis muscle biopsy
Article first published online: 3 APR 2013
Copyright © 2012 Wiley Periodicals, Inc.
Muscle & Nerve
Volume 47, Issue 5, pages 766–768, May 2013
How to Cite
Uenaka, T., Kowa, H., Sekiguchi, K., Nagata, K., Ohtsuka, Y., Kanda, F. and Toda, T. (2013), Myositis with antimitochondrial antibodies diagnosed by rectus abdominis muscle biopsy. Muscle Nerve, 47: 766–768. doi: 10.1002/mus.23730
- Issue published online: 22 APR 2013
- Article first published online: 3 APR 2013
- Accepted manuscript online: 21 NOV 2012 05:29AM EST
- Manuscript Accepted: 14 NOV 2012
- antimitochondrial antibody;
- anti-M2 antibody;
- cardiac complication;
- primary biliary cirrhosis
Antimitochondrial antibodies are autoantibodies detected in 90% of primary biliary cirrhosis (PBC) patients. Some PBC cases are complicated by myositis, which is difficult to confirm due to minimal histological evidence of inflammation in limb muscles.
Our aim was to determine the extent of inflammatory changes in a truncal muscle biopsy specimen from a PBC patient.
A 48-year-old woman with a 5-year history of atrial fibrillation and chronic heart failure was evaluated for elevated serum creatine kinase level. Antimitochondrial M2 antibodies were detected, and PBC was diagnosed. A biceps brachii biopsy specimen showed mild, non-specific myogenic changes; a second biopsy was performed on the rectus abdominis muscle, which showed typical inflammatory changes. Myositis with antimitochondrial M2 antibodies was confirmed.
In myositis patients with antimitochondrial M2 antibodies, muscles of the extremities are involved to a lesser extent. Radiological and histological examination focusing on truncal muscles, including a biopsy, is important. Muscle Nerve 47: 766–768, 2013