The MITAX, MYOACT and MDI tools, which are now undergoing validity testing, should enhance the consistency, comprehensiveness and reliability of disease activity and damage assessment in patients with myositis.

No abstract

Infliximab treatment was not effective in refractory inflammatory myopathies. In view of radiological and clinical worsening, and activation of the type I IFN system in several cases, infliximab is not an alternative treatment in patients with treatment-resistant myositis.

Objective. To investigate the benefits and safety of an intensive muscular training program in patients with chronic polymyositis (PM) and dermatomyositis (DM).Methods. Nine patients with chronic PM or DM (median age 53 years, range 44 -61) were included. Assessments of impairment (10 -15 voluntary repetition maximum [VRM], the Functional Index 2 [FI-2], the Grippit, and pain rated on the Borg CR-10 scale), activity limitation (Myositis Activities Profile), and participation restriction (patients' disease impact on well-being) were performed 4 weeks prior to baseline, at baseline, and after 7 weeks of exercise. A 6-item core set of disease activity measures was administered and muscle biopsy samples of vastus lateralis were obtained at baseline and after 7 weeks of exercise. Response criteria at an individual level were set for disability and disease activity. The patients exercised 3 days per week for 7 weeks on loads allowing 10 VRM. Results. On a group level there were no significant differences between assessments at 4 weeks before baseline compared with baseline. The group improved significantly regarding 10 -15 VRM and FI-2 at 7 weeks compared with baseline (P < 0.05). All patients were responders with respect to impairment and 2 were activity limitation responders whereas participation restriction remained unchanged in all. Two patients were responders with reduced disease activity and no patient had signs of increased muscle inflammation in the muscle biopsy sample after 7 weeks of exercise. Conclusion. Patients with chronic, stable PM and DM can perform this intensive resistive exercise program with beneficial effects on impairment and activity limitation without increased muscle inflammation.

IntroductionThis randomized, controlled study on patients with polymyositis or dermatomyositis was based on three hypotheses: patients display impaired endurance due to reduced aerobic capacity and muscle weakness, endurance training improves their exercise performance by increasing the aerobic capacity, and endurance training has general beneficial effects on their health status.MethodsIn the first part of this study, we compared 23 patients with polymyositis or dermatomyositis with 12 age- and gender-matched healthy controls. A subgroup of patients were randomized to perform a 12-week endurance training program (exercise group, n = 9) or to a non-exercising control group (n = 6). We measured maximal oxygen uptake (VO2 max) and the associated power output during a progressive cycling test. Endurance was assessed as the cycling time to exhaustion at 65% of VO2 max. Lactate levels in the vastus lateralis muscle were measured with microdialysis. Mitochondrial function was assessed by measuring citrate synthase (CS) and β-hydroxyacyl-CoA dehydrogenase (β-HAD) activities in muscle biopsies. Clinical improvement was assessed according to the International Myositis Assessment and Clinical Studies Group (IMACS) improvement criteria. All assessors were blinded to the type of intervention (that is, training or control).ResultsExercise performance and aerobic capacity were lower in patients than in healthy controls, whereas lactate levels at exhaustion were similar. Patients in the exercise group increased their cycling time, aerobic capacity and CS and β-HAD activities, whereas lactate levels at exhaustion decreased. Six of nine patients in the exercise group met the IMACS improvement criteria. Patients in the control group did not show any consistent changes during the 12-week study.ConclusionsPolymyositis and dermatomyositis patients have impaired endurance, which could be improved by 12 weeks of endurance training. The clinical improvement corresponds to increases in aerobic capacity and muscle mitochondrial enzyme activities. The results emphasize the importance of endurance exercise in addition to immunosuppressive treatment of patients with polymyositis or dermatomyositis.Trial registrationClinicalTrials.gov: NCT01184625

Our results indicate that this home exercise programme can be safely employed in patients with stable, inactive PM and DM, with beneficial effects on muscle function.

Objective. To determine the effects of a 12-week endurance exercise program on health, disability, VO 2 max, and disease activity in a multicenter randomized controlled trial in patients with established polymyositis (PM) and dermatomyositis (DM), and to evaluate health and disability in a 1-year open extension study.

Objective. To test the hypothesis that oral creatine supplements with exercise are more effective than exercise alone in improving muscle function in patients with established dermatomyositis or polymyositis receiving chronic medical therapies who are clinically weak yet stable. Methods. In a 6-month, 2-center, double-blind, randomized controlled trial, patients were randomized to receive oral creatine supplements (8 days, 20 gm/day then 3 gm/day) or placebo. All patients followed a home exercise program. The primary outcome was aggregate functional performance time (AFPT), reflecting the ability to undertake high-intensity exercise. Secondary outcomes included a functional index measuring endurance and muscle bioenergetics on 31 P magnetic resonance spectroscopy ( 31 P MRS). Patients were receiving stable immunosuppressive treatment and/or corticosteroids. Results. A total of 37 patients with polymyositis or dermatomyositis were randomized (19 to creatine, 18 to placebo); 29 completed 6 months. Intent-to-treat analyses demonstrated that AFPT improved significantly at 6 months with creatine (median decrease 13%, range -32-8%) compared with placebo (median decrease 3%, range -13-16%; P ‫؍‬ 0.029 by Mann-Whitney U test). A completer analysis also showed significant benefits from creatine (P ‫؍‬ 0.014). The functional index improved significantly with both creatine and placebo (P < 0.05 by paired Wilcoxon's rank sum test), with a significant benefit between groups in the completer analysis only. Phosphocreatine/␤-nucleoside triphosphate ratios using MRS increased significantly in the creatine group (P < 0.05) but not in the control group. No clinically relevant adverse events were associated with creatine. Conclusion. Oral creatine supplements combined with home exercises improve functional performance without significant adverse effects in patients with polymyositis or dermatomyositis. They appear safe, effective, and inexpensive.