title: Two cases of refractory polymyositis accompanied with steroid myopathy.
abstract: Polymyositis (PM) is an inflammatory muscle disease characterized by chronic inflammation in skeletal muscle. Although most patients with PM respond to corticosteroids, some cases show an unsatisfactory response and other therapeutic options must be considered. Furthermore, glucocorticosteroid (GC) toxicity leads to a significant disability known as steroid myopathy, particularly in elderly patients. Here we report two patients with refractory PM. Combined treatment with high-dose GCs, tacrolimus, and intravenous immunoglobulin resulted in beneficial effects against myositis. However, muscle weakness and the disability progressed due to steroid myopathy, and subsequent oral intake became impossible because of swallowing disturbance in these two patients. Nutritional intervention, including branched-chain amino acids (BCAAs) and rehabilitation, was undertaken in addition to treatment against myositis. These treatments finally improved the muscle weakness and activities of daily living, and the two patients were discharged after recovery. The high-dose GC treatment caused elevation of serum levels of amino acids, including BCAAs, but these amino acids subsequently declined during BCAA replacement therapy. These findings suggest that the catabolic effects of the glucocorticoid treatment impair the balance of amino acids, including BCAAs, within the muscle, leading to steroid myopathy.
authors.affiliation: Department of General Internal Medicine and Rheumatology, NHO National Nagasaki Medical Center , Omura , Japan.
authors.forename: Yasumori
authors.initials: Y
authors.lastname: Izumi
authors.forename: Taiichiro
authors.initials: T
authors.lastname: Miyashita
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Kitajima
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yoshimura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeoka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Eguchi
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Motomura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Migita
mesh_terms: D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008875:Middle Aged; D018908:Muscle Weakness / Q000139:chemically induced* / Q000188:drug therapy; D018482:Muscle, Skeletal / Q000187:drug effects; D017285:Polymyositis / Q000188:drug therapy*; D016559:Tacrolimus / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D016756:Immunoglobulins, Intravenous; D016559:Tacrolimus
keywords: Branched-chain amino acids; Glucocorticoid; Polymyositis; Steroid myopathy